MXPA98010744A

MXPA98010744A - Methods and devices for oxidizing an hydrocarbon to form an ac

Info

Publication number: MXPA98010744A
Application number: MXPA/A/1998/010744A
Authority: MX
Inventors: W Dassel Mark; C Decoster David; M Rostami Ader; Vassiliou Eustathios; M Aldrich Sharon
Original assignee: Rpc Inc
Priority date: 1996-06-24
Filing date: 1998-12-15
Publication date: 2000-08-01

Abstract

Methods and devices are described for controlling the reaction of a hydrocarbon to an acid by making adjustments related to the phase. In order to improve the reaction rate and reactivity of the oxidation, a single phase is obtained at the operating temperature and it is maintained by adjusting one or more of the gaseous oxidant flow rate, pressure in the reaction zone, temperature in the zone of reaction, hydrocarbon feed regime, solvent regime, water feeding regime if the water is being fed, catalyst feed rate and other parameters. Methods and devices are also described, wherein a hydrocarbon is reacted in a state of rest with a gaseous oxidant to form an acid in a liquid mixture. The amount of water is maintained between a maximum level of water, above which the maximum level substantially single liquid phase is transformed to two liquid phases and a minimum level below which the catalyst is precipitated. Furthermore, methods are described, wherein the temperature of the mixture is decreased to the point at which the solid dibasic acid precipitates, while maintaining a single liquid phase and optionally all the catalyst in solution. At least part of the formed acid is then removed. The preferred hydrocarbon is cyclohexane, the preferred acid is adipic, the preferred solvent is acetic acid and the preferred catalyst is cobal acetate tetrahydrate.

Description

METHODS AND DEVICES FOR OXY GIVING A HYDROCARBON TO FORM A N OCI TECHNICAL FIELD ICO This invention relates to methods and devices for forming reaction products and especially dibasic acids, by oxidizing a hydrocarbon under controlled conditions. PREVIOUS ICA TECHNIQUE There is a plethora of references (both patent and articles in the literature) dealing with the formation of acids, one of the most important being adipic acid, by oxidation of hydrocarbon. Adipic acid is used to produce Nylon 66 fibers and resins, polyesters, polyurethanes and various other compounds. There are different processes to manufacture adipic acid. The conventional process involves a first step of oxidizing cyclohexane with oxygen or a mixture of cyclohexanone and cyclohexanol (KA mixture) and then oxidizing the mixture of KA with nitric acid to adipic acid. Other processes include, the "Hydroperoxide Process", the "Boric Acid Process" and the "Direct Synthesis Process", which involves the direct oxidation of cyclohexane to adipic acid with oxygen in the presence of solvent, catalyst, initiators or promoters . The Direct Synthesis Process has been given attention for a long time. However, little commercial source has been found to date. One of the reasons is that although it looks very simple at first glance, it is extremely complex indeed.

Due to this complexity, you can find results, comments and major conflict reviews in different references.

It is well known that after a reaction has taken place according to the Direct Synthesis, a mixture of two liquid phases is present at room temperature, together with a solid phase mainly consisting of adipic acid. The two liquid phases have been called the "Polar Phase" and the "Non-Polar Phase". However, no attention has been paid to the importance of the two phases except for the separation of the adipic acid from the "Polar Phase" and recycling these phases to the reactor partially or totally with or without additional treatment. It is also important to note that most studies on Direct Oxidation conducted in a batch mode, literally or for all practical purposes. There are a plethora of references dealing with the oxidation of organic compounds to produce acids, such as, for example, adipic acid and / or intermediates, such as for example cyclohexanone, cyclohexanol, cyclohexyl hydroperoxide, etc. The following references, among the plethora and others, can be considered as representative of oxidation processes related to the preparation of diacids and intermediates. Patent of E. U.A. 5,463,119 (Kollar, U.A.A. Patent 5, 374,767 (Drinkard et al.), U. U.A. Patent 5,321,157 (Kollar), U.A.A. Patent 3,987, 100 (Barnette et al.), U.S. Patent 3, 957, 876 (Rapoport et al.), U.S. Patent 3,932, 513 (Russell), U.S. Patent 3,530,185 (Pugi), U.S. Pat. US 3,515,751 (Oberster et al.), US Patent 3,361,806 (Lidov et al.), US Patent 3,234,271 (Barker et al.), US Patent 3,231,608 (Kollar), US Patent 3,161,603 (Leyshon et al.), US Patent 2,565,087. (Porter et al.), U.S. Patent 2,557,282 (Hamblet et al.), U.S. Patent 2,439,513 (Hamblet et al.), U.S. Patent 2,223,494 (Loder et al.), U.S. Patent 2,223,493 (Loder et al.), German Patent DE 4426 132 A1 (Kysela et al.), PCT International Publication WO 96/03365 (Constantini et al.) None of the above references, or any other reference known to the inventors describe, suggest or imply, only or in combination, oxidation reactions to the intermediate oxidation products under conditions subject to intricate and critical controls and requirements of the present invention as described and claimed. Our Patents of E.U.A. 5,580,531, 5,558, 842, 5,502,245, as well as our International PCT Publication WO 96/40610 describe methods and apparatus in relation to control reactions in atomized liquids. DESCRIPTION OF THE INVENTION As mentioned above, the present invention relates to methods and devices for oxidizing a hydrocarbon, such as cyclohexane for example, to an acid, such as adipic acid for example. More particularly this invention pertains to a method for controlling in a first reaction zone the oxidation of a hydrocarbon to form an acid in the presence of a catalyst, a solvent, an optional initiator, water, and oxidation products.; the hydrocarbon, the catalyst, the solvent and at least part of the oxidation products that at least partially form a liquid mixture, the method characterized by the steps of: (a) contacting the liquid mixture with a gaseous oxidant in the first reaction zone at a first temperature, the first temperature being suitably high for oxidation to proceed; (b) driving the oxidation to a stable state at a first level of hydrocarbon, a first level of solvent, a first level of catalyst and a first level of water; (c) controlling at least one of the first hydrocarbon level, the first level of the solvent, the first level of the catalyst and the first level of water, in a manner that causes the formation and / or maintains a single liquid phase in the first reaction zone, regardless of the presence or absence of a solid phase and if necessary; (d) make adjustments related to the phases of the liquid mixture, the adjustments related to phases being based at least partially on the phase formation ratios, wherein the liquid mixture is at a second temperature, and wherein the adjustments related to phases approaches the formation and / or maintenance of a single liquid phase.

The second temperature is preferably substantially the same as the first temperature. However, it may be different than the first temperature. The adjustments related to phases of the mixture of liquids in the first reaction zone, can be carried out by a variable selected from a group consisting of temperature in the first reaction zone, pressure in the first reaction zone, flow of gaseous oxidant in the first reaction zone, water flow rate in the first reaction zone, water removal rate of the first reaction zone, rate of catalyst flow in the first reaction zone, flow rate of hydrocarbon in the first reaction zone, regime of hydrocarbon removal in the first reaction zone, solvent flow regime in the first reaction zone, solvent removal regime in the first reaction zone, gas flow regime recycled in the first reaction zone and a combination thereof. It is preferable that the method comprises a step to determine one or more of: a maximum hydrocarbon level, a maximum water level and a maximum catalyst level, at or above which, the single liquid phase is transformed to two liquid phases; and a minimum solvent level, at or below which, the single liquid phase is transformed into two liquid phases; under a group of conditions, where the levels that are not being determined remain constant. The step to determine one or more of the levels, in or on which, the single liquid phase is transformed to two liquid phases, can further comprise the steps of: obtaining a sample of a mixture of liquids from the first reaction zone; and adding to the sample hydrocarbon, or water, or catalyst, or a combination thereof, until a second liquid is formed. The first hydrocarbon level, the first water level and the first level of catalyst are preferably controlled to be below the maximum hydrocarbon level, the maximum water level and the maximum catalyst level, respectively, and the first level of solvent is controls to stay above the minimum solvent level. The sample can be analyzed to obtain data of sample compositions and therefore of the contents of the reaction zone. The composition data of the sample can be compared with phase diagrams and the adjustments related to the phase can be made in the first reaction zone, if the formation of a second liquid phase is being achieved. The composition data of the sample can also be compared with one or more of the maximum hydrocarbon levels, the maximum water level, the maximum catalyst level and the minimum solvent level and then adjustments related to the phase can be made in the first reaction zone, if one or more of the maximum hydrocarbon level, the maximum water level, the maximum catalyst level and the respective minimum solvent level, is being reached. If the additional hydrocarbon, or water, or catalyst necessary for the formation of a second liquid phase is less than 10% by weight of the total hydrocarbon, or water, or catalyst contained in the reaction zone or a sample from the reaction zone, then the maximum level of hydrocarbon or water or catalyst is being reached and corrective measures have been taken. Examples of said corrective measures is to reduce the first level of hydrocarbon or the first level of water or the first level of catalyst, or increase the first level of solvent, or a combination thereof. It is preferable that the additional hydrocarbon, or water, or catalyst, necessary for the formation of a second liquid phase should be controlled to more than 10% (and in some cases, more than 20%) by weight of the hydrocarbon, or total catalyst water, respectively, contained in the reaction zone or a sample taken from them. One or more of the first hydrocarbon level, the first catalyst level and the first water level can be controlled to stay within a majority scale, or a minority scale. The majority scale is defined as a scale between a high predetermined majority level and a low majority level predetermined, the high majority level being below the maximum level at or above which the maximum level of a second phase is formed, the majority level low. being between the high majority level and an average of the maximum level and a minimum level and below which the catalyst of the minimum level precipitates. It is also preferable that the high majority level approaches the level at which the formation of the second phase is approaching. At other times, it may be preferable that the first level of water and / or the first level of solvent be controlled to remain within a minority scale, the minority scale being a scale between a predetermined low minority level and a predetermined high minimum level, the low minority level being above the minimum level at or below which the catalyst precipitates and the high minority level being between the low minority level and an average of the minimum level and maximum level, at and above which the level is formed maximum of a second phase. The high importance of controlling the diverse levels within the majority and / or minority scales, is that within these scales the unintentional and / or accidental formation of the second liquid phase or catalyst precipitation is minimized, if not eliminated . Depending on each individual case, and the degree of control that can be achieved, the high and low majority and minority levels can be predetermined. The first temperature can be controlled by evaporating the condensable volatile material from each reaction zone and by recycling at least part of the condensable volatile material to the reaction zone as it condenses. The methods and devices of the present invention are particularly suitable in the case that the acid comprises adipic acid, that the hydrocarbon comprises cyclohexane, that the solvent comprises acetic acid, that the catalyst comprises a cobalt salt and that the optional initiator comprises an compound selected from a group comprising, acetaldehyde, cyclohexanone and a combination thereof. The methods of this invention may further comprise a step of controlling at least one level of the first level of water and the first level of solvent in a manner that is higher than the respective level, at or below which, the catalyst is precipitated.; and the first level of hydrocarbon and the first level of catalyst that is lower than a respective level, in or on which, the catalyst precipitates. The above methods may further comprise the steps of: taking a sample from the first reaction zone; decreasing the temperature of the sample to a second predetermined temperature, and if a second liquid phase is formed at a critical temperature on the scale between the first and second temperatures; any decrease in the first reaction zone of the first level of a component selected from a group consisting of hydrocarbon, water, catalyst and a mixture thereof to a degree that a second liquid phase is not formed in a new sample on the scale between the first and second temperatures, or increase the reaction zone of the first level of solvent to a degree that in a new mixture a second liquid phase is not formed in the scale between the first and second temperatures, or increase in the first zone of Reacting the first temperature to a third temperature to at least the difference between the critical temperature and the second temperature, or a combination thereof. It is preferable that the level of water within the upper or lower limits be controlled (maximum level of water on which a second liquid phase is formed and the minimum levels of water below which the catalyst is precipitated, respectively) is based on in determining the composition of a single phase liquid mixture of the first reaction zone, comparing the composition with phase diagrams and catalyst precipitation data and adding water to a single phase liquid mixture in the first zone of reaction if the lower limit is being reached or removing water from the first reaction zone if the upper limit is being reached. The methods of this invention may also comprise combinations of the following steps: taking a sample from the first reaction zone; confining the sample within a closed cell under adequate pressure to retain the sample in a substantially liquid form; raising the temperature of the cell of the first temperature to a higher temperature; and if the catalyst is precipitated within a predetermined elevation in temperature; Raise the water level or the solvent level in the first reaction zone, decrease the hydrocarbon level or the level of catalyst in the first reaction zone. In a different version of the present invention, the methods may comprise a combination of the following steps: forming a sample from the first reaction zone; confining the sample within a closed cell under adequate pressure to retain the sample in a substantially liquid form; adding hydrocarbon to the sample to determine if the catalyst is precipitated before the formation of a second phase; and controlling in the first reaction zone the first level of hydrocarbon that will be maintained at a level below the level required to cause precipitation at levels of solvent, catalyst and water present in the cell. The methods of this invention may further comprise the steps of: decreasing the first temperature of the reaction mixture to a second temperature, while maintaining a single liquid phase at the second temperature; and remove at least part of the acid formed. The decrease of the first temperature of the reaction mixture to the second temperature can be carried out at least partially by an operation selected from a group consisting of: (a) evaporating at least part of the hydrocarbon, (b) decreasing the first pressure at a second pressure, (c) adding matter that has a temperature lower than that of the first temperature, (d) adding volatile matter, such as cyclohexane for example, (e) removing heat by external means, (f) remove a first amount of heat by any suitable means and add a second amount of clear by external means, the first amount of heat being greater than the second amount of heat, and (g) a combination of the same. The maintenance of a single liquid phase at a second temperature can be controlled by adjusting the level of hydrocarbon, or water, or solvent, or a combination thereof, to the second temperature. The decrease of the first temperature to a second temperature can preferably be carried out in a second zone. The decrease in the first temperature at the second temperature may involve an intermediate step of lowering the first temperature to a first intermediate temperature by lowering the first pressure to an intermediate pressure to form a first intermediate liquid phase containing no substantial amount of solid phase. The methods and devices of the present invention are particularly suitable in the case that the acid comprises adipic acid, that the hydrocarbon comprises cyclohexane, that the solvent comprises acetic acid, that the catalyst comprises a cobalt salt, and the optional initiator comprises a compound selected from a group comprising acetaldehyde, cyclohexanone and a combination thereof. At least part of one or more of the products, intermediates, by-products, reagents, solvents, gases and other existing ingredients can be recycled either directly to the first reaction zone or indirectly after the post-treatment, or in a combination thereof . The present invention also relates to a reactor device for oxidizing a hydrocarbon, the hydrocarbon being at least partially in a liquid state, with a gaseous oxidant to form an acid, the device comprising: a first reaction chamber; a temperature monitor connected to the reaction chamber by measuring the temperature inside the reaction chamber; the phase detection means to detect characteristics related to phase of the ingredients within the first reaction chamber; and phase control means for forming phase related adjustments and controlling the phase characteristics of the ingredients within the first reaction chamber, if desired. The phase control means may further comprise temperature control means for controlling the first temperature. The phase control means may further comprise correlation means for correlating the phase diagram data with ingredients in the reaction chamber and adjusting the feed rates of the ingredients to the reaction chamber for the formation of a single liquid phase . The phase detection means can provide information to the phase control means by adjusting the feed rates of the ingredients fed into the reaction chamber towards the formation or maintenance of a single liquid phase. The reactor device of the present invention can further comprise variable control means for controlling in the reaction chamber a variable selected from a group consisting of temperature in the first reaction chamber, pressure in the first reaction chamber, flow rate of gaseous oxidant in the first reaction chamber, water regime in the first reaction chamber, rate of water removal in the first reaction chamber, rate of catalyst flow in the first reaction chamber, rate of hydrocarbon flow in the first reaction chamber, the hydrocarbon removal regime in the first reaction chamber, the solvent flow rate in the first reaction chamber, the gas flow rate recycled in the first reaction chamber and a combination thereof. The reactor device may further comprise: liquid feeding means for at least partially supplying hydrocarbon, solvent, catalyst, optionally initiator and optionally water in the first reaction chamber; means for removing water to remove water from the first reaction chamber; gas feed means for feeding oxidant into the first reaction chamber; and water level control means for controlling the water level in the reaction chamber on a scale between approximately a minimum level of water, over which the maximum level of substantially a single liquid phase is transformed to two liquid phases and a lowest level at which the catalyst precipitates. The water level control means may comprise water level sensing means for detecting the water level placement with respect to the maximum level and the minimum level. The reactor device may also comprise a controller connected to the water level sensing means for receiving information regarding the placement of the water level and using said information to adjust the water level in a way to control the water level between the maximum level and the minimum level in the reaction zone.The water level sensing means may comprise a temperature operated detector, or an operated water addition detector or both to detect the placement of the water level with respect to the minimum level and the maximum level, respectively. In addition, the water level control means may comprise means for detecting the level of the analytical water to detect and / or determine the water level in the first reaction chamber and wherein the reactor device further comprises a controller connected to the Analytical water level detection means to receive information regarding the water level in the reaction chamber, compare the information with the phase diagram data and catalyst precipitation data, stored in the controller and using the comparison to adjust the level of the water in the first reaction chamber in a way that the water level is controlled between the maximum level and the minimum level. The reactor device may further comprise a distillation column or a condensate, connected to a line of gas exiting the first reaction chamber. A decanter or reaction chamber can be connected to the condenser. The water level sensing means may comprise a temperature operated detector for detecting the placement of the water level with respect to the minimum level and / or a detector operated by the addition of water to detect the placement of the water level with respect to the water level. maximum level.

The reactor device can also comprise: first temperature control means connected to the first reaction chamber for controlling the temperature in the first reaction chamber; first pressure control means connected to the first reaction chamber for controlling the pressure in the first reaction chamber; first hydrocarbon feed means connected to the first reaction chamber to feed hydrocarbon into the first reaction chamber; first means for feeding gaseous oxidants connected to the first reaction chamber for feeding gaseous oxidant into the first reaction chamber; a second chamber connected to the first reaction chamber; second temperature control means connected to the second chamber for controlling the temperature in the second chamber; second pressure control means connected to the second chamber for controlling the pressure in the second chamber; a controller to control various parameters in the cameras in a way that in the second chamber there is a single liquid phase. A co-denser or de-concentration column can be connected to the second reaction chamber and to the second chamber. A holding chamber or decanter can be connected to the condenser.

The reactor device may further comprise a first intermediate chamber communicating with the first reaction chamber; first intermediate temperature control means connected to the first intermediate chamber for controlling the temperature in the first intermediate chamber; first intermediate pressure control means connected to the intermediate chamber for controlling the pressure in the first intermediate chamber; first intermediate external heating means for supplying thermal energy to the material within the first intermediate chamber; a capacitor connected to the first intermediate chamber; separation means connected to or being part of the second chamber for at least partially separating the dibasic acid from the mixture. It may further comprise: a second intermediate chamber connected to the first intermediate chamber and the second chamber; second intermediate external cooling means for removing the thermal energy of the matter within the second intermediate chamber. A second phase control means can be connected to the second chamber ensuring the existence of a single liquid phase in the second chamber. As well, a catalyst precipitation control means can be connected to the second chamber to ensure the absence of the precipitated catalyst in a second chamber. Under certain circumstances, at least two of the cameras can be one and the same unit. One or more of the reaction chambers or other chambers may be of the atomization or stirred reactor type. In any of the chambers described above, the means to add heat by internal or external means, removing the heat by internal or external means, adding volatile matter, removing volatile matter, controlling temperature, controlling pressure, etc. , they can be incorporated. In the embodiments described herein, the amount of water present includes amounts of water introduced by other means, such as crystalline water of cobalt acetate tetrahydrate (I I), for example, unless otherwise specified. In the case where water, such as crystalline water for example, is not taken into account to be part of the water level, then it is counted by being part of the entity that introduces it, such as a catalyst for example. This invention covers both cases. The control can be achieved either by taking into account the additional water, such as for example the crystalline water of the catalyst, or taking into account said additional water, depending on the particular situation. By the term "state at rest" it is understood that the reaction has reached an equilibrium, whose equilibrium, however, can be adjusted periodically or continuously in order to achieve a desired result. If, for example, more water is needed in the reaction zone to avoid catalyst precipitation, the water feed rate to the reaction zone can be increased appropriately and still the reaction can be considered to be a "state in repose". Similarly, if less water is needed to avoid the formation of two phases, the water feed rate to the reaction zone can be properly lowered and still the reaction can be considered to be in a "quiescent state". The terms "substantially a single liquid phase", "substantially a single liquid phase", "single liquid phase" and "single phase" are for all purposes synonymous for the purposes of this invention. They are intended to indicate that there is no second liquid phase present, while a solid phase may or may not be present. The terms "second phase formation" or "second stage formation" refer to a second liquid phase and not a solid phase, unless otherwise specified. The term "level" of an ingredient (reactant, reaction product, inert material or any other type of material present) includes both "the relative level" and the "percentage level". According to the present invention, both methods and devices can be carried out using either one or the other type of "levels". Sometimes it may be easier to use one type instead of another. "Relative Level" of an ingredient denotes the amount of the ingredient present in units of weight or units of volume, in a reaction zone or in a cell for example, compared to 100 units, in units of weight or in units of volume, respectively, of the rest of the ingredients present, or the rest of the ingredients under consideration. The rest of the ingredients present or the rest of the ingredients under consideration, in this case, have a constant relationship with respect to one another. On the other hand, the "percentage level" is the level expressed as a percentage based on the total amount of all or a desired number of specific ingredients. The percentages can also be expressed by weight or volume. A controller, preferably a computerized controller, can easily and accurately handle any type of "level". Programming a computerized controller to perform these functions is a routine process, well known in the art. In accordance with this invention, a controller, based on received information, of a reaction zone for example, controls feed rates, temperatures, pressure and other parameters in order to achieve convenient results. Since the pure results with respect to the point of a formation of the second liquid phase (the results of which are received from a cell, such as the cells shown in Figures 2, 2A and 2B, which will be discussed in detail in a later section) they are obtained in relative levels, the maintenance or adjustments in the reaction zone are more precise when the "relative levels" are used. The controller can also be programmed, as is well known by those skilled in the art, to include flowchart simulation, which can be taken into account for the vapor / liquid balance and energy balance effects. BRIEF D ESCRI PCIÓ N OF DIJJJOS The understanding of the reactor of this invention will be improved by reference to the following detailed description taken in combination with the figures of drawings, wherein: FIGURE 1, schematically illustrates a preferred embodiment of the present invention. FIGURE 2 schematically illustrates an analyzer, which can be used in accordance with the present invention. FIGURE 3 illustrates the response of the phase analyzer of Figure 2 when the detector tracks the analyzer cell, which contains two liquid phases. FIGURE 4 shows the elements related to the pressure and gaseous oxidant flow rate controls. FIGURE 5 shows a ternary phase diagram of (acetic acid) / (cyclohexane) / (water) at 100 ° C at the level of 0% cobalt acetate tetrahydrate (I I). FIGURE 6 shows a ternary phase diagram of (acetic acid) / (cyclohexane) / (water) at 100 ° C at the level of 4% cobalt acetate tetrahydrate (I I). FIGURE 7 illustrates a block diagram of another preferred embodiment of the present invention.

FIGURE 8 schematically illustrates a top water level monitor, which can be used in the embodiment of the Figure 7, and which can also be used to determine conditions for substantially maintaining a single liquid phase during the activation of a hydrocarbon. FIGURE 8A schematically illustrates a monitor of the upper water level based on conductivity measurements, which can be used in the embodiment of Figure 1 and which can also be used to determine conditions for substantially maintaining a single liquid phase during the oxidation of a hydrocarbon. The monitor is displayed under conditions of substantially a single liquid phase. FIGURE 8B schematically illustrates the same upper water level monitor, based on conductivity measurements, as shown in Figure 8a under conditions of a second liquid phase formation. FIGURE 9 illustrates the response of a phase analyzer of Figure 8, when the detector tracks the analyzer cell, which contains two liquid phases. FIGURE 10 schematically illustrates a monitor of the lower water level, which includes a second cell, prior to precipitation of the catalyst after a predetermined elevation in temperature.

FIGURE 11 schematically illustrates the same monitor of the lower water level of Figure 10, after precipitation of the catalyst. FIGURE 12 shows a graph, which illustrates an example of how the predetermined elevation in temperature of the second cell of the monitor of Figure 10 can be determined. FIGURE 13 illustrates a block diagram of another preferred embodiment of the present invention, comprising a first reaction chamber and a second chamber. FIGURE 14 illustrates a block diagram of another preferred embodiment of the present invention, wherein external heating means have been provided between the first reaction chamber and the second chamber. FIGURE 15 illustrates a block diagram of yet another preferred embodiment of the present invention, wherein both the external heating means and the external cooling means have been provided between the first reaction chamber and the second chamber. BEST MODE FOR CARRYING OUT THE INVENTION As mentioned above, this invention relates to methods for forming intermediate oxidation products, such as acids, for example, by oxidizing a hydrocarbon with a gas containing an oxidant, preferably oxygen. A tubular rolling mini-reactor containing steel balls was used for a series of experiments. The steel balls were added to provide a highly improved surface factor by distributing a thin film on the surface of the steel balls. The surface factor is defined in this case as the ratio of the surface area of the liquid / gas interface per unit volume of liquid. The mini-reactor comprised of a tubular stainless steel case having an internal diameter of 1.8 cm, an external diameter of 5.7 cm, an external length of approximately 29.21 cm and an internal length of approximately 24.13 cm. The total capacity of the mini-reactor was 75 ce. Approximately 890 stainless steel balls having a diameter of 0.3 cm were used in the mini-reactor as agitation and mixing means, together with a rolling action of +33 degrees from the horizontal a frequency of 10 cycles per minute, unless that is established in another way. The mini-reactor had a top screw cap, a number of internal and external thermocouples to measure and control the temperature. It was surrounded by a heating tape and insulated with fiberglass. It had gas and liquid feed ports. It was also provided with a pressure transducer. Both temperature and pressure were recorded and controlled through a computer using supervisory control software. In operation of the mini-reactor, the following procedure was followed, unless otherwise stated. The system was initially purged with nitrogen, the feed was added, while purged with nitrogen, through the top of the mini-reactor that had an uncrowned position, the mini-reactor was crowned and purged again with nitrogen to a pressure of approximately 3.5 kg / cm2, the temperature was raised to the desired degree (usually from 100 to 105 ° C), the pressure was brought to approximately 7.03 kg / cm2 with nitrogen and the oxygen was introduced at a pressure of 7.03 kg / cm2 , thus bringing the total pressure around 14.06 kg / cm2. The pressure (P) and the pressure drop rate (d P / dt), among other variables, was then recorded. Unless the substantial reaction does not take place, the dP / dt goes from a regime of substantially zero to a maximum and then drops from nine to a substantially zero regime. In the different graphs or tables, when the terms "reaction regime" and "reactivity" are used, they correspond to the maximum d / dt in each particular case, unless otherwise noted. An initial sharp peak that precedes the maximum is not considered since it is thought to correspond to a rapid oxidation of the initiator, such as acetaldehyde for example. In the case where cyclohexanone is used as the initiator, said preceding peak is not acute or pronounced. Although the terms "promoter" and "initiator" are often used in the literature and in this work interchangeably to mean "exchanger", the stricter meaning of the term "initiator" should be used for a substance that decreases the reaction initiation period , such as acetaldehyde or cyclohexanone, or methyl ethyl ketone, for example, and the term "promoter" should be used for a substance that promotes the reaction, such as bromide ions in the case of producing terephthalic acid a. from p-xi leno, for example. The inventors also used a high pressure stirred glass tube to determine phase relationships under conditions of the actual temperature, pressure and reaction composition. The analysis of the reaction products was carried out by CLAR and CG, both of which are well known to those skilled in the art. After achieving a reaction in the di-straight Synthesis of cyclohexane to adipic acid, a mixture of two liquid phases at room temperature is present, together with a solid phase which mainly consists of adipic acid. The two liquid phases have been called the "Polar Phase" and the "Non-Polar Phase". However, no attention has been paid to the importance of the two phases, except for the separation of adipic acid from the "Polar Phase" and to recycle these phases to the reactor partially or totally with or without additional treatment.

The inventors of the present invention, using the above apparatuses, unexpectedly discovered that both the composition and a number of relations between the "Polar and" Non-Polar "phase are of greater importance for the reactions that take place during the Direct Synthesis. It was found that not only the ratio of the phases to the reaction temperature is important, but also the data on the ratio of the phases at room temperature can be used to control the reaction at reaction temperatures, which is totally unexpected, given that the phase relationship can change dramatically with temperature According to the present invention, the "Polar Phase" is a liquid phase containing predominantly polar components, while the "Non-Polar Phase" is a liquid phase containing predominantly polar components. In addition, when two liquid phases are present, one of which is more polar than to another is the "Polar Phase", while one that is less polar is the "Non Polar Phase". Under certain controlled circumstances, as explained in more detail below, the two phases can be operated in one phase, which is called the "Single Phase" according to this invention. The "Single Phase" may be a "Single Polar Phase" if it contains predominantly polar components, or a "Single Non-Polar Phase" if it contains predominantly non-polar components. In addition, as the temperature increases, one of the two phases may increase and the other decrease. If the "Polar Phase" decreases in a way that is finally absorbed by the "Non-Polar Phase", then the "Single Phase" formed as a "Non-Polar Phase Only". Similarly, if the "Non-Polar Phase" decreases in a way that is eventually absorbed by the "Polar Phase", then the "Single Phase" formed is a "Single Polar Phase". Regardless of the type of the phase, the "TA" phase is a phase that exists at room temperature; the "75 ° C" phase is a phase that exists at 75 ° C; the "100 ° C" phase is a phase that exists at 100 ° C, and so on. The ambient temperature is approximately 20 ° C. When phases are mentioned in this discussion, reference is made to the liquid phases, unless the solid phases are specifically cited and established as such. For purposes of clarity and brevity, the most preferred constituents can be used to exemplify the methods of the present invention, rather than more generic terms. For example "acetic acid" can be used in place of "solvent", but it should be understood that any other suitable solvent can be used in such methods. Examples of less preferred solvents are butyric acid, propionic acid, etc. In a similar form "acetaldehyde" can be used in place of the more generic name "promoter", and "cobalt acetate tetrahydrate" or "cobalt acetate" (both meaning "cobalt acetate tetrahydrate" unless otherwise specified). another way) can often be used in place of the term "catalyst". In addition to the formation of adipic acid, the methods of the present invention can also be applied to other monobasic or dibasic acids from the corresponding cyclic aliphatic hydrocarbons or aromatic hydrocarbons. Examples are the formation of glutaric acid of cyclopentane, formation of pimelic acid of cycloheptane and the like. In addition, the teachings of this invention can be used for the formation of benzoic acid from toluene, formation of phthalic acid to part of o-xylene, formation of isophthalic acid of m-xylene, formation of terephthalic acid of p-xylene and Similar.

From the point of view of quantity, the main polar component in the reaction mixture is acetic acid having a specific gravity slightly higher than 1 g / cc, and the main non-polar component is cyclohexane having a specific gravity slightly less than 0.8 g / cc, the polar phase is heavier than the non-polar phase, and if both are present, the non-polar phase tends to move towards the upper part, while the polar phase tends to move downwards. Therefore, in a test tube if a sample has a polar phase and a non-polar phase, the polar phase will reside in the lower part of the tube and the non-polar phase will reside in the upper part of the tube. It has been observed by the inventors that the addition of very small amounts of water, as well as very small changes in the amount of cobalt acetate tetrahydrate (I I), have a substantial effect on the ratio of the two phases. It is speculated that it occurs because water and cobalt acetate tetrahydrate (l l) are very polar compounds. For example, the composition of Table 1 was found to be in the form of two phases at room temperature. The lower phase, which is the polar phase of TA, constituted only about 3% (by volume) of the total, while the non-polar phase of TA constituted about 97 (by volume) of the total. At this point it is very important to note that substantially the total amount of the catalyst, determined colorimetrically, resided in the lower polar phase. For example, in this case, the upper phase was colorless and transparent, while the lower phase had a dense magenta color. As shown in Tables 2 and 3, after adding approximately only 0.4% (by weight) of the water to the composition shown in Table 1, the polar phase volume of TA increased approximately 17% (by volume). As more water was added, the polar phase of TA increased more and approximately 6% (by weight) water, the polar phase of TA constituted approximately 30% (by volume) of the total. The initial addition of water had a considerably greater effect on the increase of the polar phase of TA than the addition of additional amounts of water. However, at low concentrations of cyclohexane and higher concentrations of acetic acid, the water had a considerably lower effect on the ratio of the two phases. During the reaction of cyclohexane with oxygen, a considerable amount of water is produced, and therefore, the presence of water is a factor and not a matter of choice.

By adding a small amount (approximately 0.4 to about 1% by weight) of water an appreciable amount of polar phase of TA was formed (approximately 20% by volume). Then, by separating the two phases, and re-mixing them in different proportions to form the whole of a reaction feed mixture, it was unexpectedly found that, in the case of the mini-reactor, the reactivity of the mixture was proportional to the amount of the polar phase of TA present at a certain point and then decreased.

This drop in the batch-type mini-reactor may be due to the exhaustion of cyclohexane. TABLE 1 COMPOSITIONS OF MOTHER SOLUTION INGREDIENTS GRAMS% WEIGHT% MOLAR Acetate tetrahydrate 0.34 0.71 0.21 Cobalt (II) Acetic Acid 14.68 30.58 38.09 Acetaldehyde 0.34 0.71 1.20 Cicehexane 32.64 68.00 60.49 Total 47.00 TABLE 2 FOOD SOLUTIONS CONTAINING DIFFERENT AMOUNTS OF WATER Graduated Cylinder # I II III IV V VI Weight of Cylinder Empty gm 52.34 34.59 34.26 35.60 39.03 39.94 Weight of Cylinder + Mother Solution gm 57.39 39.74 39.44 40.97 44.49 40.13 Weight of the Feed Solution gm 5.06 5.15 5.18 5.36 5.46 5.19 Weight of Cylinder + Solution of gm 57.39 39.76 39.49 41.07 44.68 40.48 Feeding + Water Aggregate Water Weight gm 0.00 0.02 0.05 0.11 0.19 0.35 % in Weight of Water Added 0.00 0.41 0.94 1.92 3.36 6.33 TABLE 3 VOLUME OF POLAR PHASE OF TA (BOTTOM) COMPARED WITH THE NON-POLAR PHASE OF TA (SUPERIOR) Graduated Cylinder # i ii iii iv v vi Volume (mi) before Upper Phase 6.3 6.2 6.2 6.4 6.3 6.4 Add water Bottom Phase 0.2 0.2 0.2 0.3 0.3 0.3 Volume (mi) after Upper Phase 6.3 6.3 5.1 5.3 5.0 4.8 add water Lower Phase 0.2 1.1 1.3 1.4 1.8 2.0 % of Volume of the Water Phase before the addition 3.1 3.1 3.1 4.5 4.6 4.5 Water after the addition 3.1 17.1 20.31 20.9 26.5 29.4 It was also observed that at a level of approximately 20% polar phase of TA, specifically in case iii of Table 3, as the temperature increased, the polar phase progressively contracted to a very small volume and finally disappeared in the non-polar phase at a temperature of approximately 100 ° C. The consequence of this was that as the polar phase (which as mentioned before contains the majority, if not substantially all the catalyst) contracts between 80 ° C and 100 ° C, at some point it becomes over-saturated with the catalyst, which resulted in the precipitation of the catalyst. This is highly undesirable not only due to the highly diminished availability of the catalyst, but also because the material precipitated in a reactor causes loss of the utility of the reactor and plant, and the high cost of maintenance due to the obstruction of the lines, etc. Upon further heating the solution under vigorous stirring, at about 100 ° C, a single non-polar phase is formed and most of the precipitated catalyst is redissolved in the single polar phase, while it remains at rest in the precipitated form. Therefore, in this particular case, although a reaction of cyclohexane with oxygen could proceed at temperatures lower than 100 ° C, the reaction rate and reactivity could be considerably reduced, because the dissolved catalyst has been reduced, because the catalyst has dissolved in a very small polar phase, or precipitate. Another consequence of this is that unless a temperature of 100 ° C, or higher, is used, in this particular case, it is very difficult to contact the volume of the material, which is in the non-polar phase which substantially contains all the available cyclohexanone, with the catalyst, all of which resides substantially in the very small amount of the polar phase and with the gaseous oxygen phase. The concentration of water in the reactor, due to water formation, greater than one represented by cases ii and iii in Table 3, will significantly worsen the aforementioned detrimental effects. Higher temperatures may not always be a practical remedy for these problems, because in order to improve chemical performance, it may be advantageous to operate the reaction at lower temperatures. At relatively low proportions different from polar phase of TA to non-polar phase of TA (approximately less than 30% or 40% polar phase, in this particular case), there is a critical temperature for phase or phase transition, below which two liquid phases are formed, and the polar phase, which contains the majority, if not substantially all the catalyst present, which cause the reaction regime and reactivity suffer considerably. Therefore, it is important to operate the reaction at or above that temperature. It is more preferable to operate the reaction at a temperature of at least 5 ° C above the critical temperature for phase or the phase transition temperature. For different compositions, the critical temperature for the phase will vary, but it will be very easy to determine it using a transparent, high-pressure stirred glass bottle into which the mixture is introduced and the temperature rises with simultaneous observation of changes in temperature. phase. It should be emphasized that, as the amount of water present in the composition increases, the contraction decreases when the polar phase is heated and finally the two phases do not become a single phase, even at elevated temperatures, even at temperatures higher than desirable reaction temperatures. Therefore, in order to obtain a single phase, it is preferable that water and / or hydrocarbons be controlled by removal (water and hydrocarbon increase the critical temperature for phase), or the amount of solvent increased (the solvent decreases). the critical phase temperature). As the amount of acetic acid in a composition increases (including both polar and non-polar phases), the composition can withstand the presence of more water without the formation of two liquid phases within the range of convenient reaction temperatures. It is also observed that approximately a polar phase of TA of 65%, as the temperature increases, the non-polar phase contracts, and at a temperature of 97 ° C, it was completely absorbed by the polar phase to form a single polar phase , as defined above. In addition, it was observed that at higher amounts of water present (approximately 7% by weight of the total composition), the presence of two liquid phases still persisted at 120 ° C. Therefore, it is convenient that the reaction be operated in a manner that the amount of water remains adequately low (or removed), so as to avoid the formation of two phases at the operating temperature. As mentioned before, it was also observed that the larger the amount of polar phase of TA, the faster the reaction will be to a certain extent. A similar relationship was also observed between the maximum pressure drop regime (representing the reaction rate) and the absolute amount of catalyst in the mini-reactor.

It was also completely unexpected to find that the selectivity of molar percentage to adipic acid did not change with the polar phase of AT of present weight percentage or with the amount of catalyst present. It remained substantially constant. The selectivity of molar percentage to adipic acid was defined as the moles of adipic acid formed in the reaction, multiplied by 100 and divided by the sum of moles formed of adipic, glutaric and succinic acids. It was also found that, within the limits examined, the adipic acid selectivity was independent of the amount of acetaldehyde present or the molar ratio of acetaldehyde to cobalt acetate (I I). With respect to the TA and other temperature of the polar and non-polar phases, it should be noted that their compositions can vary considerably depending on the amount and nature of the catalyst, water, solvent, hydrocarbon, initiator, etc. Therefore different conclusions established below are related to the polar and non-polar phases made as described in each particular case. However, a person with ordinary experience in the field, based on the teaching of this invention, you can find desired relationships of other polar and non-polar phases on other occasions only with minimal effort. The implications of this finding have a huge impact on a large number of aspects with respect to the direct synthesis of adipic acid by oxidation of cliclohexane with oxygen. These findings indicate the following important steps of the process, among others that can be carried out to drastically improve and control the oxidation process. These steps can be carried out individually or in any combination, depending on the circumstances, including but not limited to, reactor design, design of reactor peripherals, pre-existing or new reactor, parameter limits, etc. (1) Because the reactivity shows a maximum on a scale of approximately 65% of the polar phase of AT (it is made in composition iii of Table 2) and above, especially, without sacrificing selectively, the reaction would appear to be directed towards This scale of the polar phase of TA (however, one should keep in mind the increase of the total level of catalyst when it increases in the polar phase of TA. (2) because the reactivity (the amount of reaction that takes place in a given reaction volume) shows a similar behavior with respect to the level of the catalyst, especially without sacrificing the selectivity, the reaction should be carried to the higher catalyst level, preferably under a point of precipitation at which the catalyst begins to precipitate. 3) because the cyclohexane is the main contributor to the formation of the non-polar phase, the reaction should preferably be directed towards the minimum amount of cyclohexane in t to the way that there is always an adequate amount of cyclohexane in the forms of liquid and vapor in order to avoid the depletion of the reaction due to the lack of cyclohexane; in all cases it is preferable that it is controlled below the amount that is formed that causes a second phase to the reaction conditions; the minimization of cyclohexane in the reactor has a very important additional beneficial effect, which is related to safety; in the case of accidental operation in the reactor, there will be considerably less fuel (cyclohexane) to promote an explosion; (4) Because acetic acid is a major contributor to polar phase formation, the reaction should be directed to the maximum amount of acetic acid in such a way that excessive dilution is prevented or prevented; this step should preferably be coordinated with step (3) so that the amount of acetic acid does not cause a decrease in the amount of cyclohexane to cause depletion of the reaction due to lack of cyclohexane; preferably, the amount of acetic acid used should be such that it produces a polar phase ratio from TA to nonpolar phase of TA on the scale of more than about 65% of the polar phase of TA by combining with a suitable amount of cyclohexane to avoid the exhaustion with cyclohexane of the reaction. (5) In order to operate with a single-phase system, which is highly operable for multiple reasons, the reaction should be maintained at a temperature equal to or higher than the critical phase temperature (as defined above) within the limits to ensure selectivity and production do not suffer from unacceptability. (6) Because water is a strong contributor to the formation of two phases of a single phase, which is undesirable, but which is thought to aid in the hydrolysis of the desired ester by-products formed during the reaction and due to which is also thought to increase the production and selectivity of adipic acid, its content in the reaction mixture should be directed to the maximum amount of water that does not cause the formation of a two-phase, single-phase system to at least one reaction temperature, unless the downstream separations are adversely affected in doing so. (7) In order to prevent or prevent the precipitation of the catalyst at room temperature or lower at which the adipic acid crystallizes, the amount of catalyst in the mixture should be driven to the region below the point of precipitation of the catalyst in the mixture. reacted and cooled; A preferred embodiment of this invention is illustrated in Figure 1. In Figure 1, a device or continuous reactor system 10 comprising a reaction chamber 12 is described. A recycle intake or inlet line 14, a new raw material feed or intake line 16, a feed line or gaseous oxidant admission 18, a gas outlet line 19, a sampling line 20, a predominantly non-gaseous expulsion line 21 and means for measuring temperature, such as thermocouples 22 and 24, for example, are connected to the reaction chamber 12. Other elements, commonly used with reaction chambers, such as for example pressure monitors and controllers, and the like, although preferably used in accordance with the present invention, are not shown in Figure 1 for the purpose of clarity Also, the optional means for carrying out the chemical analysis of the contents of the reaction chamber 12 are not shown, also for purposes of clarity. The sampling line 20 leads to a phase analyzer 26, which provides information of the liquid phase to a computerized controller 28 through the intake line 26 '. An example of the phase analyzer will be described at a later point. The optional means (not shown) for carrying out the chemical analysis of the content of the reaction chamber 12, preferably, also provides information of the content of ingredients to the computerized controller 28. The lines of introduction, expulsionThe words "admission" or "expulsion" are used for lines that feed or extract materials, respectively, while the words "entry" and "entry" or "exit" can be placed in a suitable location in reaction chamber 12. output "are used for lines that provide information to the computerized controller 28, or are used by the controller to control other elements of the device, respectively. The gas-free ejection line predominantly for non-gaseous materials leads to a handling station of 30, in which the reaction products, either by-products, unconverted raw materials, are separated by techniques well known in the art. Such techniques may involve filtration, distillation, crystallization, other types of separation, evaporation, cooling, heating, storage, decontamination, incineration, disposal, etc. The desired product of reaction follows the product path 32, the non-recyclable byproducts follow the path of non-recyclable 34, while the recyclable materials follow the line of recyclables 36, whose line 36 leads to an analytical apparatus 38 for content analysis of recyclables. The analytical apparatus 38 shows the recyclables for analysis and allows the largest portion of said recyclables to enter line 36ii. The line 36 may comprise one of a plurality of lines, depending on the nature of the recyclables. Some of these lines may include the analytical apparatus 38, if so desired (if for example the content of the recyclable material under consideration is known or previously determined by any of the techniques well known in the art.) Recyclables follow the line 36ii, which leads to a three-way valve 39, in a way that the recyclables can follow line 40 or 42 or both in any desired ratio.The line 42 leads back to the material handling station 30 for storage or retention or return to work it, or the like, while line 40 leads to a first heat exchanger (including cooler or heater or the like) 44. The 3-way valve 39 is controlled by the computerized controller 28 through the outlet line 38". Similarly, the heat exchanger 44 is controlled by the computerized controller 28 through the output line 44. Preferably one or more input lines (not m ostradas for clarity purposes) provide temperature information to the computerized controller 28 with respect to the recyclables as they enter and leave the heat exchanger 44. The recyclables enter the reaction chamber 12 after they pass through the flow meter 46, which gives flow data of recyclables to the computerized controller 28 through the input line 46 '. The input lines 22 'and 24' feed the computerized controller 28 with temperature information inside the reaction chamber 28. Both lines may be necessary, or only one, or more than two, depending on the information required in each particular case . The flow regulation valves 50, 52, 54, 56 and 58 are connected to the input lines 50i, 52i, 54i, 56i and 58i, which provide hydrocarbon, solvent, catalyst, promoter and other adjuncts, respectively, to a vessel Pre-mixed 48. The premixed container 48 is preferably small in size and placed in a form that all of its contents leave it and through line 16, so that if more than one phase is present, there is no accumulation of a particular phase in the pre-mixing vessel. The pre-mixing vessel 48 is connected to a second heat exchanger (including cooler or heater or the like) 60, which in turn is connected to the reaction chamber 12. The input lines 50i, 52i, 54i, 56i and 58i, however they can be connected directly to the second heat exchanger 60 or to the reaction chamber 12. The flow regulation valves 50, 52, 54, 56 and 58 are controlled by the computerized controller 28 through the output lines 50", 52", 54", 56" and 58", respectively A number of flow meters (not shown for of clarity) connected to the lines 50i, 52i, 54i, 56i and 58i, provide flow information regarding the hydrocarbon, solvent, catalyst, promoter and other adjuncts, to the computerized controller 28 through a multiple input line 62. The Reaction chamber 12 can be heated or cooled by heating means (not shown) well known in the art Lines 14 and 16 can be fused in a single line (not shown) and fed to the reaction chamber through a single line The phase analyzer 26 or an additional phase analyzer (not shown) can also be connected to this single line, so as to detect the presence of a second qualitative or quantitative phase, even before the liquid enters the chamber. reaction and an It is preferable that the determination of the second phase takes place under the same temperature and pressure of the reaction (if the pressure is not excessive). An example of the phase 26 analyzer is best illustrated in ia Figure 2. It can comprise a cell at least partially transparent 62 for accepting liquid from the reaction chamber 12 and a detector 66 adapted to move up and down the height of the cell 62, in order to detect the presence of more than one liquid phase 64. The nature of cell 62 is preferably such that it accepts high pressures, preferably similar to reaction pressures. The detector 66 can be a color detector, a refractive index detector, an ultrasonic detector, or in general any type of detector that can distinguish and differentiate between liquids using a property of the two liquids, whose property can differentiate one from the other. other. If the phases are separated by a lower phase that have a height "a" and towards an upper phase that has a height "b", the differential of the property detected by distance traced dP / ds ("p" being the property, such as for example color, and "s" being the distance traced as shown by arrows A) will give a graph as shown in Figure 3, where a '/ b' = a / b, from which the degree of the second phase formation can be determined.

If the phases are difficult to separate into different portions, additional techniques can be used to assist in separation. Centrifugation, ultra-centrifugation, addition of flocculation agents and the like are examples of such techniques. Although in Figure 2 the detector 66 is shown to reside outside the cell, it can reside very well inside cell 62. A conductivity detector is an example of a detector that should come into contact with the liquid phases and preferably be inside. of the cell. The detector can be a single detector that travels up and down the cell height, or in some way travel the cell, or it can be two or more detectors located at rest in different positions of the cell. In the case of using two detectors, it is preferable to use a detector in the vicinity of the lower part of the cell and a detector in the vicinity of the upper part of the cell. It is obvious that in the case of relative movement of the detector with respect to the ceida, the cell can be the moving element and the detector can be the element at rest. Instead of using a detector, an observer can visually detect the levels of the two liquids and provide this information to the computerized controller 28. The phase detector can also be based on the measurement or detection of the turbidity (velocity) of the mixture. one phase dispersed in another the other phase, since the phases, for all practical purposes and substantially always, will have different refractive indices. A single liquid phase will be transparent, but a second phase dispersed in another phase will produce a cloudy mixture. Care must be taken in this case to filter any solid matter before determining the turbidity. The light screening can also be used for the detection of a finely emulsified second phase in a first liquid phase. The temperature at which the cell 62 and its contents are subjected can be room temperature in the range of 20 to 25 ° C, any other temperature, or preferably the same temperature as the first temperature, which is the reaction temperature in the reaction chamber 12 in the area where the reaction occurs (reaction zone). Depending on the temperature at which cell 62 operates it may have to be under pressurized conditions and closed to maintain its content in the liquid state. In operation of this embodiment (see Figure 1), the hydrocarbon, solvent, catalyst, promoter and any other desired adjunct are added to the pre-mixed container 48, where they are mixed. The pre-mixing vessel is small enough and placed in a way that if there is a phase separation, no particular part remains, but all phases are combined and proceed through the second heat exchanger 60 and the reaction chamber 12 through line 16. Feeding regimes of the new raw materials fed through lines 50i, 52i , 54i, 56i and 58i depend on the feed rates of the recyclables fed to the reaction chamber 12 through the recharge feed line 14. Information regarding the analytical results of the analytical apparatus 38 is provided to the computerized controller 28, which combines this information with the information of the flow meter 46 and the information of the flow meters (not shown) of the lines 50¡, 52i, 54i, 56i and 58i, and calculates the total feeding regime of each individual ingredient that enters the reaction chamber 12. The computerized controller preferably gives precedence to the recyclables, and then adjusts each of the valves 50, 52 , 54, 56 and 58 through the output lines 50", 52", 54", 56", and 58", respectively, in a way that the total feed rate of each individual ingredient entering the chamber reaction 12 has a desired value. The desired value of each ingredient feeding regime is preferably adjusted to the formation and maintenance of a single phase at the reaction temperature, otherwise called the first temperature. Of course, when the operation begins, there are no recyclable materials, so that only new raw materials begin to enter the system through one or more of lines 50i, 52i, 54i, 56i and 58i and finally enter into the system. the reaction chamber 12 through the line 16. During the start of the operation, the different feed rates of the new raw materials are arranged so that a single phase comes out at the first temperature. As mentioned before, when discussing a single phase of multiple phases in this description, the inventors mean a single phase or multiple liquid phases. When the inventors wish, they refer specifically to a solid phase. The rest of the materials are also preferably arranged to make such that when the water begins to form during oxidation a second phase is not formed. The amount of water formed depends on the conversion taking place when the system obtains a resting state. Most solvent, acetic acid for example, is present in this state at rest, most of the water can be supported by the system without the formation of a second phase. Since water formation is substantially unavoidable when a hydrocarbon is oxidized and in some aspects its presence may still be desirable (at least for partial hydrolysis of undesirable ester byproducts, for example), it is preferable to work it to a state at rest on the which may contain at least a predetermined water content without the formation of a second phase. Removal of water at any step of the process, if necessary or desired, can be achieved in a number of ways, including for example distillation, addition of acid anhydrides and other methods well known in the art. The more hydrocarbon, cyclohexane, for example, is present in the reaction chamber, the greater the potential for the formation of a second phase. At the same time, if very little hydrocarbon is present, the reaction begins to run out due to lack of hydrocarbon. In accordance with the present invention, the amount of hydrocarbon present in the resting state is preferably just above the point at which depletion is observed. "Just above" depletion means preferably between 0 to 20% above depletion and more preferably from 5 to 20% above depletion. At the same time that the ingredients mentioned above intone reaction chamber 12, a gas containing an oxidant, preferably oxygen, enters the reaction chamber through the gaseous oxidant feed line 18, and comes into contact with the mixture containing the hydrocarbon. The reaction temperature, or first temperature, is monitored by one or more thermocouples, such as thermocouples 22 and 24, for example, which provide temperature information to the controller 28. The computerized controller 28, based on this temperature information sets the first and second heat exchangers through the outlet lines 44"and 60", respectively, in a form that in combination with the heat released by the reaction and the thermal characteristics of the reaction chamber 12, the first temperature obtains and maintains a desired value. In order to lower the temperature in the reaction chamber, the heat exchangers are adjusted to lower the temperatures in lines 14 and 16. In addition, instead, the reaction chamber itself can be provided with means of heating and / or cooling (not shown for purposes of clarity, but well known in the art), controlled by the computerized controller 28, so that the temperature obtains and maintains the desired value. The desired value, of course, can be a desired scale of values. As the first temperature or reaction temperature rises, the potential for single-phase formation increases, and the rate of reaction increases. However, the selectivity of the desired final product may suffer. Therefore, a balance between the reaction regime, selectivity and the reaction temperature (first temperature) has to be decided. Therefore, the decision may depend on the particular circumstances and can be based on economic, safety, environmental and other considerations. Therefore, the temperature can be adjusted through the computerized controller 28 within the desired scale in a way that promotes the formation and / or maintenance of a single phase. If a single phase already exists, the temperature can preferably be reduced to the minimum limit of the desired scale and maintained there, if this decrease in temperature does not cause the formation of a second phase. The decrease in pressure within the reaction chamber 12 moves the system to a single-phase formation because more hydrocarbon, cyclohexane, is evaporated for example and the hydrocarbon content in the liquid decreased. If the inert gases are present in the gaseous oxidant (if the gaseous oxidant is predominantly a mixture of oxygen and nitrogen, for example), it is preferable that the partial pressure of the oxidant, oxygen, for example, be kept constant during the decrease in pressure total. The increase of diffused gas in the case of a stirred tank reaction chamber, or in general the flow of the gaseous oxidant in the case of an atomization reactor (described for example in our Patent and Patent Application mentioned above) has an effect similar in a way that decreases the pressure. The decrease of the conversion, or holding time in the reaction chamber 12, decreases the amount of water formed, which has an effect to promote the formation of a single phase. The lower conversion decreases the amount of acid formed, predominantly for example adipic acid, in the oxidation of cyclohexane, which has little or no effect on the formation of the second phase. The lower conversion also increases the amount of unreacted hydrocarbon, cyclohexane for example, present in the reaction zone that promotes the formation of two liquid phases, but this effect is small compared to the stronger effect of water. The net result is thought to be that which promotes the formation of the lower conversion of a single liquid phase. The decrease in the amount of catalyst, cobalt acetate tetrahydrate (I I) for example, also promotes the formation of a single phase. It should be noted here that when cobalt tetrahydrate (I I) is used, the water is necessarily introduced, corresponding to the hydration water of the cobaltose acetate salt. If the formation of a second phase is detected by the phase detector 26, the detector 26 transfers said information to the computerized controller 28 through the input line 26 '. The computerized controller 28 in turn performs the steps toward the reformation of a single phase in the reaction chamber 12, ordering one or more of the elements it controls to function in a manner directed to the reformation of the single phase as It is described before. Although, depending on the particular circumstances, the operation or activation of the various elements controlled by the computerized controller 28 may be arranged in any desired order of precedence, it is convenient in most cases, in accordance with the present invention, to arrange as follows: For stirred tank reactors, when the formation of a second phase is detected at the same temperature as the temperature prevailing in the reaction zone, the computerized controller gives precedence to decrease the hydrocarbon feed rate in Step form closing the valve 50 through the outlet line 50. The steps preferably are between 1 to 60% of the feed rate at the time when the formation of the second phase is detected, more preferably from 1 to 30%, and even more preferably 2 to 10%, at a predetermined time (preferably 1/2 to 10 minutes, and more preferably 1 to 2 minutes) after each step, a sample was taken again through line 20 to the phase analyzer, where it is examined, and the results are provided to the computerized controller 28. If only one has been reformed phase, no additional action is taken. If a single phase has not been formed, the same process can be repeated. If for some reason the water is fed into the system via line 58¡, the computerized controller 28 gives second precedence to valve 58 through the output line 58"and a similar procedure is followed as before. step, however, can ensure the first precedence in the event that the amount of cyclohexane fed to reaction chamber 12 moves downward to a point at which the reaction begins to run out due to lack of adequate hydrocarbon, such as cyclohexane for example, the next or third precedence is given to the gaseous oxidant flow rate through line 18, which is also regulated (not shown in Figure 1 for purposes of clarity) but the computerized controller 28, as shown in FIG. shows better in Figure 4, where most of the elements are not shown Figure 4 shows the elements related to pressure and gaseous oxidant flow rate controls. n 12 is provided with a pressure monitor 68, which transmits pressure information to computer controller 28 via the input line 68 '. The gaseous oxidant feed line is provided with a flow meter 70, which provides flow rate information to the computerized controller 12 through the input line 70 '. The computerized controller 28 controls the valve 72 on the gaseous feed line and the valve 74 on the gas expulsion line 19 through the outlet lines 72"and 74". If the steps described above are not adequate to eliminate the second phase, and provide a single phase, the computerized controller 28 opens the valve 72 in a manner that stepwise increases the flow of the value it had to a higher value, which causes removal of hydrocarbon and water. The steps or increases of the increment, preferably are between 1 to 60% of the feeding regime at the moment in which the formation of the second phase is detected, more preferably from 1 to 30% and even more preferably from 2 to 10%. As in the previous cases, a predetermined time (preferably from 1/2 to 10 minutes, and more preferably 1 to 2 minutes) after each step, a sample is taken back through line 20 to the phase analyzer, where it was examined and the results are provided to the computerized controller 28. If it has been reformed a single phase, no additional action is taken. If a single phase has not been formed, the same process can be repeated. In order to maintain the pressure inside the constant reaction chamber, the valve 74 also opens accordingly, so that the pressure is not increased as detected by the pressure monitor 68.

The next or fourth precedence is given to the pressure inside the chamber 12. If the steps described above are not adequate to eliminate the second phase and provide a single phase, the computerized controller 28 further closes the valve 72 and also opens the valve 74 in a way that the pressure decreases step by step the value it had at a lower value. The steps or increases in pressure are preferably between 5 to 30% of the pressure at the time the formation of the second phase is detected, more preferably from 5 to 20%, and even more preferably from 10 to 20%. As in the previous cases, a predetermined time (preferably 1/2 to 10 minutes and more preferably 1 to 2 minutes) after each step, a sample was taken again through line 20 to the phase analyzer , where it is examined and the results are provided to the computerized controller. 28. If you have reformed a single phase, no additional action is taken. If a single phase has not been formed, the same process is repeated. In order to maintain the partial pressure of the oxidant constant, which is a preferred mode of operation, the oxidant, for example of oxygen, can be added through an additional door (not shown). The computerized controller gives the fifth precedence to increase the solvent supply regime, for example acetic acid, by step opening the valves 52 through the outlet line 52. The steps are preferably between 1 to 60% of the régime. They are fed from the initial feed, more preferably from 1 to 30% and still more preferably from 2 to 10%, at a predetermined time (preferably 1/2 to 10 minutes, and even more preferably from 1 to 2 minutes). from each step, a sample was taken again through line 20 to the phase analyzer, where it is examined and the results are provided to the computerized controller 28. If a single phase has been reformed no additional action is taken. a single phase has been formed, the same process is repeated, the computerized controller gives the sixth precedence to reduce the conversion or increase the feeding regime of all the incoming raw material, excluding the catalyst and the regime of the products that leave through the predominantly gas-free exit line 21, all in a proportional manner. This increase was carried out in steps by additionally opening the simplified valves, in a way that all the allocations increase and the product that leaves flows proportionally to the others. The steps preferably as in other cases between 1 to 60% of the initial feed rates and outflows, more preferably from 1 to 30% and even more preferably from 2 to 10%. At a predetermined time (preferably 1/2 to 10 minutes, and more preferably 1 to 2 minutes) after each step, a sample is taken again through line 20 to the phase analyzer, where it is examined and the results are provided to computerized controller 28. If you have reformed a single phase, no additional action is taken. If a single phase has not been formed, the same process can be repeated.

The seventh precedence is given to the temperature, with permitted increments only within a predetermined region as described above. The eighth precedence is given to decrease the rate of catalyst feeding. In the above description of precedence to obtain and maintain a single phase within the reaction zone, mention is made only of valves for introducing new raw materials. However, it should be understood that this could preferably be carried out in combination with the control of the recyclables of information received from the analytical apparatus 38 through the input line 38 ', and of the flow meter 46, by adjusting the flow through the the valve 39 and the temperature through the heat exchanger. In the case of atomization reactors, the temperature control to obtain and maintain a single phase could take at least the third precedence. It should also be noted that a combination of different levels of preference can be used in a multi-step process at each precedence level. For example, the computerized controller can be programmed to carry out only one step or a predetermined number of steps in each level of precedence, the number of steps being the same or different at each particular level. Also, the computerized controller can be programmed to change the precedence levels, depending on the particular circumstances. A preferable type of computerized controller comprises a "learning computer" or a "neuro-computer", the functionality of which is known in the art and which collects information from different places on the device (for example, pressure, temperature, analysis). chemical or other, etc.), stores this information together with the result (reaction regime, for example) and is scheduled to use this information in the future, along with other data if applicable, to make decisions regarding the action which should be taken (for example with respect to precedence, steps within precedence, etc.) in each case. Although the various functions are preferably controlled by the computerized controller 28, if possible, in accordance with this invention, use manual controls to control one or more functions. If the phase analyzer is at room temperature, the correlations can be made between the analytical results and the polar phase relationship TA to nonpolar phase of TA. If the ratio is small with substantially all of the catalyst in the polar phase of TA, the solvent should be added in amounts adequate to the ratio of solvent to hydrocarbon of preferably greater than 0.5, and more preferably between 0.5 and 1 at water levels preferably less than 5% All relationships in this discussion are by weight, unless stated otherwise.

As mentioned before, the methods of the present invention may also comprise a step to correlate the phase diagram data with selected variables from a group consisting of temperature in the reaction zone, pressure in the reaction zone, flow rate of gaseous oxidant, water feed rate, catalyst feed rate, hydrocarbon feed rate, solvent feed rate and a combination thereof, in order to control the oxidation of the hydrocarbon by controlling preferably in the reaction zone a variable selected from a group consisting of temperature in the reaction zone, pressure in the reaction zone and flow regime of gaseous oxidant, water feed rate, catalyst feed rate, hydrocarbon feed rate, solvent feed and a combination thereof. An example of said a ternary phase diagram of (Acetic Acid) / (Cyclohexane) / (Water) at 100 ° C, at a catalyst level of 0%, shown in Figure 5, wherein the regions of a Ri phase and two phases of R2 will be separated by the transition line T0. The region of a phase R1 is above the transition line T0, while the two-phase region of R2 is below the transition line T0. Another example of said ternary phase diagram of (Acetic Acid) / (Cichloxane) / (Water) at 100 ° C, at a level of 4% catalyst is shown in Figure 6, where the regions of an R-phase And two phases R2 are separated by the transition line T. The region of a phase R ^ is above the transition line T4, while the region of two phases R2 is under the transition line T4. As can be seen, the presence of a catalyst, in this case cobalt acetate (II) tetrahydrate, suppresses the region of one. phase to a certain degree. The presence of adipic acid in the mixture of the components does not substantially change the transition curve. Ternary diagrams for different levels of catalyst, temperature and / or other components, which can influence the transition curves can be created very easily, preferably experimentally. Thermodynamic databases and computer flowchart simulation programs can be used, for example, as guidelines for determining the approximate position of the transition curve, which is refined and defined more precisely by limited experimentation. An easy way to build an experimental ternary diagram at a given catalyst level, temperature, etc. , for example, to select different positions in the region of a phase of the theoretical diagram close to the theoretical transition curve and to start the addition of water until a second phase is formed. This will define an experimental point on the experimental transition curve for the given catalyst level, temperature, etc. The exact compositions of different experimental points in the diagrams shown in Figures 5 and 6 are listed in Tables 4 and 5, respectively. The points to the left of point 1 are omitted because the amount of cyclohexane involved is too small for most practical purposes. TABLE 4 COMPOSITIONS THAT DEFINE THE TRANSITION CURVE T0 IN FIGURE 5 Experimental Data (0% Catalyst) Components Quantity% in Quantity% in (grams) weight (grams) weight Acetic Acid 1 15.105 75.70 2 15.589 77.93 Water 3.750 18.79 2.646 13.23 Cichonhexane 1.099 5.51 1.768 8.84 Total 19,954 20,000 Acetic acid 3 15.124 75.27 4 12.005 62.18 Water 1,762 8.77 0.895 4.64 Cyclohexane 3.207 15.96 6.408 33.19 Total 20,093 19,308 Acetic acid 5 9.859 48.30 6 6.550 32.75 Water 0.537 2.63 0.140 0.70 Cyclohexane 10,018 49.08 13,310 66.55 Total 20,411 20,000 TABLE 5: COMPOSITIONS THAT DEFINE THE TRANSITION CURVE T4 IN FIGURE 6 With 4% Catalyst Base catalyst free 1 Components Quantity% by weight Quantity% by weight (grams) (grams) Acetic acid 15,198 72.88 15,198 75.95 Cyclohexane 1,000 4.80 1,000 5.00 Catalyst 0.844 4.05 0.000 0.00 Water * 3.812 18.28 3.812 19.05 Total 20,854 20,010 2 Components Quantity% by weight Quantity% by weight Acetic Acid 17,000 76.08 17,000 79.07 Cichonhexane 2,000 8.95 2,000 9.30 Catalyst 0.844 3.78 0.000 0.00 Water * 2,500 11.19 2,500 11.63 Total 22,344 21,500 3 Components Quantity% by weight Quantity% by weight Acetic Acid 14,762 72.56 14,762 77.08 Cyclohexane 3.129 15.38 3.129 16.34 Catalyst 0.812 3.99 0.000 0.00 Water * 1,261 6.20 1,261 6.59 Total 20,344 19,152 4 Components Quantity% by weight Quantity% by weight Acetic acid 12.603 69.49 12.603 72.66 Ciciohexane 3.843 21.18 3.843 22.16 Catalyst 0.799 4.40 0.000 0.00 Water * 0.899 4.95 0.899 5.18 Total 18,144 17,345 Components Quantity% by weight Quantity% by weight Acetic Acid 13.606 67.68 13.606 70.48 Cyclohexane 4,807 23.91 4,807 24.90 Catalyst 0.798 3.97 0.000 0.00 Water * 0.893 4.44 0.893 4.63 Total 20.104 19.306 6 Components Quantity% by weight Quantity% by weight Acetic acid 9.799 47.25 9.799 49.22 Cicehexane 10,004 48.24 10,004 50.25 Catalyst 0.831 4.01 0.000 0.00 Water * 0.106 0.51 0.106 0.53 Total 20,740 19,909 * The crystalline water of cobalt acetate tetrahydrate (ll) is not included. When such diagrams are used by the controller to operate the system and ensure that the reaction is carried out in one phase, analysis of the contents of the reaction chamber, preferably by Gas and Liquid Chromatography, and the regimes can be carried out. Flows of different allocations (including recycled material) can be changed accordingly to produce characteristic blends for one phase. A similar procedure can be followed from the diagrams produced at different temperatures, so that temperature manipulations can produce the desired results. Therefore, for example, the various parameters can be changed to achieve the desired condition of a phase, including but not limited to temperature in the reaction zone, pressure in the reaction zone, gaseous oxidant flow rate, feed rate of water, catalyst feed rate, hydrocarbon feed rate, solvent feed rate and a combination thereof. We have discovered that the unexpected combination of two critical phenomena is of greater importance in the successful oxidation of a hydrocarbon, such as cyclohexane for example, to an acid, such as adipic acid for example. The first of two critical phenomena, as discussed above, is the formation of a second liquid phase during the time the reaction is taking place, if a second liquid phase is formed, during the time that the reaction is taking place. . If a second liquid phase is formed during the time the reaction is taking place, the reaction rate falls to unacceptable levels, followed by unacceptably slow conversion rates, poor yields and resulting in a totally non-economic operation for all ios practical purposes. The second of the critical phenomena is the precipitation of the catalyst during the time the reaction is taking place. Precipitation of the catalyst during the time when the precipitation is taking has similar results as the formation of the second liquid phase. Even in the case where only the partial precipitation of the catalyst takes place, this precipitation results in the deposition of the catalyst on different parts of the reactor system, plugging the pipes and valves, etc. The reaction rate and reactivity also suffer from precipitation of the catalyst. Therefore, there is a severe problem in the state of the present technique, when the reaction conditions allow precipitation or catalyst formation of a second liquid phase.

We have found that under a given set of conditions the amount of water in a liquid reaction mixture during an oxidation in the resting state of a hydrocarbon or a respective acid, has to be controlled within the critical limits defined by the point of a second liquid phase formation and point of catalyst precipitation. We have also found that under a given set of conditions and a minimum level of water under which the catalyst, for example cobalt acetate tetrahydrate (I I), is precipitated and over which the catalyst remains in solution. Speaking of the same, we have found that there is a maximum level of water on which a second liquid phase is formed and under which a single liquid phase is substantially maintained. Therefore, for a given group of conditions it is imperative that the level of water, in a liquid mixture suffering from oxidation, be controlled between a maximum level of water over which substantially a single liquid phase is transformed into two liquid phases and a minimum level, under which the catalyst is precipitated to a minimum level. The problem becomes more severe as the catalyst, for example cobalt acetate tetrahydrate (I I), increases the content and also as the hydrocarbon content increases, for example cyclohexane. It was also unexpectedly found that the catalyst, such as cobalt acetate tetrahydrate (I I) or cobalt 2-ethyl cobalt hexanoate (I I) for example, has a tendency to precipitate at higher temperatures. This unexpected finding is extremely important because it can be used to detect a water level at which the catalyst precipitation point is reached and the additional water should be added to avoid catalyst precipitation as will be described in detail below. Referring now to Figure 7, there is described a reactor system or device 1 10, comprising a reaction chamber 1 12 containing a reaction zone 1 14. Reactor system 1 10 is only partially shown to demonstrate the components necessary to exemplify the present invention. The diverse treatment, separation of product or by-product, recycling, etc. , devices, well known in the art, are not shown for purposes of clarity and brevity. The reaction chamber 1 12 comprises a reaction zone 1 14. The liquid supply means 1 15 which end in a supply line of two liquids 1 16 and a gas supply means 1 17 that end in an oxidant supply line 18, they are connected to the reaction chamber 1 12 to provide liquid feed and gaseous oxidant, respectively to the reaction zone 1 14. The reaction chamber 1 12 can be a stirred tank reactor, atomization reactor, reactor of recirculation or any type of reactor, known in the art. The liquid feed line 1 16 can be a single line or a multiple line. The liquid feed means 15 can include heat exchangers, pre-mix containers, flow meters, thermocouples, etc. , and are connected (not shown for purposes of clarity and brevity) to one or more inputs 120 of a controller 122. In turn, the controller 122 is connected to the liquid feeding means 1 15, through one of its outputs 124 and controls its operation by methods well known in the art. In a similar manner, the gaseous feed means 17 are connected (not shown for clarity and brevity) to one or more inputs 120 of a controller 122. In turn, the controller 122 is connected to the gaseous oxidant media. liquid 1 17, through one of its outlets 124 and controls its operation by methods well known in the art. In addition, the temperature monitor 126 and pressure monitor 228 are connected to the reaction chamber 12 to monitor the temperature and pressure in the reaction zone 1 14. They give relevant information to the controller 122 through the input lines (FIG. not shown) connected to the respective inputs 120 of the controller 122, so that the controller 122 adjusts the temperature and pressure to the reaction zone 14 in the reaction chamber 12, according to a predetermined manner programmed into the controller 122 by techniques well known in the art. A condenser 130 is also connected to the reaction chamber 1 12. U not for the main purposes of the condenser 130 is to remove the heat from the reaction zone 1 14. The condensable vapors, such as for example hydrocarbon, solvent, water and the like, they can be heated to reflux directly to the reaction zone 14 of the reaction chamber 112, or they can be directed to a decanter 132, where they can be separated into an upper phase and a lower phase 136. The natural gases are still line 38 to be scraped preferably in order to remove the exhaust condensables and in turn usually feeds into the atmosphere. Of course, at certain times, preferably before scraping, at least they are partially recycled to the reaction zone 114 of the reaction chamber 1 12. When they are recycled to the reaction zone, they can be introduced partially or totally, under the surface of liquids for dispersion and / or reaction. The decanter 132 is connected to the line 140, which in turn communicates totally or partially with the lines 142 and 144 through the first valve 143. Therefore, the upper phase 134 of liquid is partially or totally recycled to the reaction chamber 1 12 and / or partially or totally is removed through line 144, usually for additional treatment. The decanter 132 is connected to the line 146, which in turn communicates totally or partially with the lines 148 and 150 through the second valve 149. Therefore, the lower phase 136 of liquids is totally or partially recycled to the reaction chamber 1 12 and / or partially or totally is removed through line 150, usually for additional treatment. The first valve 143 and the second valve 149 are preferably controlled by the controller 122, so that the feed rates of each phase are recycled to the reaction chamber 12 or directed for treatment and / or disposal. Instead of the condenser 130 and the decanter 132, a distillation column (not shown) can be used for considerably better separation of the different condensed components, such as for example hydrocarbon, solvent, water, by-products, etc. Therefore, the distillation column can be used in the same way as the combination of the condenser and the decanter to remove heat and for the separation of the individual condensable components.

An analytical apparatus 152 is also connected to the reaction chamber 12 through the line 152 '. The analytical apparatus 152 is programmed by the controller 122 to take samples from the reaction chamber 12 and analyze them. This analytical apparatus preferably comprises HPLC and GC equipment, well known in the art and can be used to determine water, solvent, hydrocarbon, catalyst, oxidation products, oxidation byproducts, etc. Of course, the sampling of the contents of the reaction chamber 12 may be manual, with subsequent feeding to the analytical apparatus and after feeding the results of the analysis to the controller 122 for further processing. In addition to, or in place of the analytical apparatus 152, there is an upper water level monitor 154 (or 155) and a lower water level monitor 156 connected to the reaction chamber 1 12. The samples of the contents of the reaction 112 are provided to monitors 154 and 153 through lines 154 'and 156', respectively. As before, this operation can also be manual and / or can be based on visual observations, as will be explained in more detail later. The results of the two monitors 154 (or 155) and 156 can be fed automatically or manually to the controller 1 12. It is notorious that the upper water level monitor 154 (or 155) can also serve as a more versatile monitor for detecting the hydrocarbon level and / or catalyst level. In addition to, or instead of the water level, at which level a second liquid phase is formed. It may also serve to determine a second level of higher solvent in or on which the substantially single liquid phase is maintained or re-established in the reaction zone, despite the rise in the hydrocarbon level and / or catalyst level and / or water level, whose elevation could result in the formation of a second liquid phase if the solvent has remained at this initial level. An example of an upper water level monitor 154 is best shown in Figure 8. The water level monitor of the upper limit may comprise a first cell at least partially transparent 162 to accept the liquid from the reaction chamber 1 12 through the line 154 'and a first detector 166 adapted to move up and down the height of the first cell 162, in order to detect the presence of more than one liquid phase 164. The monitor 154 is also supplied with line 154", through which pure water or water from line 148 containing solvent, may be introduced to monitor 154 in predetermined amounts (the amount of solvent is usually greater than the amount of water in the lower phase and weight ratios of solvent to water of about 75 to 25 are within reality.) One outlet line 158 is used to remove liquids from the first cell 162 after one has been made. determination and a new determination is appropriate. The monitor 154 may also be provided with a mixing mechanism (not shown for clarity purposes), which may be based on shaking, shaking, mixing and any other technique well known in the art. Vigorous mixing is preferred. The nature of the first cell 162 of the monitor 154 is preferably such that it accepts high pressures, preferably similar to the reaction pressures. However, low pressures are also acceptable, while the contents (except for gases) of the cell are not substantially volatilized. For this purpose it is highly preferable that the cell be as complete as possible with the sample during its operation, which will be discussed in detail later. The first detector 166 can be a color detector, a refractive index detector, an ultrasonic detector or in general any type of detector that can distinguish and differentiate between liquids using a property of two liquids, that can properly differentiate one from the other. If the phases 161 are separated in a lower phase having a height "a" and in a higher phase having a height "b" the property differential detects by distance traced d P / ds ("p" being the property, such as for example color, and "s" being the distance traced as shown by arrows A) will give a graph as shown in Figure 9, where a '/ b' = a / b, from which the creation or presence and the degree of the formation of the second liquid phase can be determined. If the phases are difficult to separate into different portions, additional techniques to assist such separation can be used. Centrifugation, ultra-centrifugation, addition of flocculation agents and the like are examples of such techniques. Although in Figure 9 the first detector 166 is shown to reside outside the first cell, it may reside well inside the first cell 162. A conductivity detector of a detector example that could be in contact with the liquid preferably inside and more preferably in the lower part of the first cell 162. The first detector can be a detector only that travels up and down the height of the first cell, or in some way that tracks the first cell, or can be two or more detectors located at rest in different positions of the first cell. In the case of using two detectors, it is convenient to arrange a detector in the vicinity of the lower part of the first cell and a detector in the vicinity of the upper part of the first cell. It is obvious that in the case of the relative movement of the detector with respect to the first cell, the first cell can be the moving element and the detector the element at rest. Instead of a detector an observer can visually detect the creation or presence and levels of two liquid phases and provide this information to the controller 122. When two liquid phases are formed and are difficult to separate, the first detector 166 and can also be based in the measurement or detection of turbidity (nebulosity) of the mixture, if a liquid phase is dispersed or emulsified in the other liquid phase, because the two phases, for all practical purposes and substantially always, will have different refractive indexes . A liquid of substantially a single phase will be transparent but a second phase liquid dispersed or emulsified in the first liquid phase will produce a cloudy mixture. Care should be taken in this case to filter any solid matter before the determination of turbidity. The light screening can also be used for the detection of a second liquid phase finely emulsified in a first phase. Another example of an upper water level monitor 155, based on the conductivity detection, is shown in Figures 8A and 8B, and comprises a cell 163 similar to cell 162 of monitor 154 (Figure 8). In the vicinity of the bottom of cell 163, conductivity conductors measuring conductivity are located, by techniques well known in the art. Cell 163 is also connected to line 155 'from which it can accept a sample from reaction zone 1 14. It is also connected to line 155"through which water can be introduced. if appropriate, line 155"can be used for the introduction of other liquids, such as for example hydrocarbon, catalyst, solvent, a mixture thereof and the like. Line 159, connected to cell 163, is used as an output line for the contents of cell 162, when no more are needed. Figure 8A shows a phase in cell 163, while Figure 8B shows a formation of the second liquid phase, which can be easily detected by conductivity probe 167, since the reaction phase formed will have a slightly different conductivity compared with a liquid phase system. Because the hydrocarbon, such as cyclohexane for example, with a small amount of dissolved solvent, is lighter than water with a large amount of dissolved solvent, such as acetic acid for example, the second liquid phase, which will be the polar phase, will reside in the lower part of cell 163 and will give a highly increased conductivity. Therefore, it will be detected more easily. More conductivity probes can be placed in different positions of the cell to detect the relationships of the two phases, if desired. In the case where the second liquid phase is expected to take place in the vicinity of the upper part of cell 163, the conductivity probe can be placed in a consequently appropriate position. A low water level monitor 156, to detect catalyst precipitation, is best illustrated in Figures 10 and 11. The monitor 156 comprises a second cell 164 at least semi-transparent, and preferably transparent, which is provided with heating means, such as heating coil 160 for example and a second detector 168, which is capable of measuring light absorption (preferably visible in this particular case), or turbidity and the like, through a medium. The second cell 164 is also provided as a thermocouple 170 to monitor the temperature of the contents of the second cell 164.

The second cell 164 is connected to the line 156 'from which it is supplied with the liquid mixture from the reaction zone 1 14 of the reaction chamber 1 12. An output line 172 is used to remove the liquids. of the second cell 164 after a determination has been made and a new determination is convenient. The monitor 156 is preferably provided with a mixing mechanism (not shown for purposes of clarity), which may be based on shaking, shaking, mixing and any other technique well known in the art. The second cell 164 preferably is such that it accepts high pressures and temperatures as in the case for the first cell 162. The analytical apparatus 152, shown in Figure 7, may comprise one or more devices or one or more groups of devices for analyzing no. only the composition of reaction zone 14, but also the composition of various streams. A liquid transfer line 174 is connected to the reaction chamber 1 12 to remove the flowable matter from the reaction zone 1 14 for removal of the oxidation product, such as adipic acid for example, additional treatment for removal of undesirable byproducts, recycling of other material, etc. In operation of this embodiment, the hydrocarbon, such as cyclohexane for example, solvent, such as acetic acid for example, catalyst, such as for example cobalt acetate tetrahydrate, and an initiator such as for example cyclohexanone and acetaldehyde, are initially charged in reaction zone 1 14 of reaction chamber 1 12 through line 1 16. As mentioned above, line 1 16 can be a single line or a multiple line for introducing raw material as a whole or as individual currents or as combinations of currents. A small amount of water (for example 0.2 to 2% by weight based on the total charge, depending on individual circumstances) can also be added to the reaction zone 1 14. The raw material can be introduced at a reaction temperature, whose reaction temperature in the case of cyclohexane adipic acid preparation is preferably in the range of about 60 to 160 ° C, more preferably in the range of 80 to 120 ° C, and even more preferably in the 90 ° to 1 10 ° C. Alternatively, the raw material may be introduced at a different temperature than the reaction temperature, preferably at a lower temperature and then brought to the reaction temperature by means of heating or cooling elements, consequently inside or outside the reaction chamber 12. In the case of a stirred tank reactor, the reaction chamber is filled to a predetermined degree, preferably larger than the capacity of the reaction chamber 12. In the case of an atomization reactor, preferably, a small charge in the The lower part of the reaction chamber 1 12 is introduced, which is recirculated from the upper levels to the reaction chamber 12 towards the interior of the reaction chamber 12, in the form of a spray, as discussed in our patents and applications mentioned above that deal with atomization reactors. For purposes of simplicity, the following discussion will be directed predominantly at stirred tank reactors. The temperature is monitored by the temperature monitor 126 and the pressure by the pressure monitor 128. The temperature monitors, for example such as thermocouples and pressure monitors, for example as voltage gauges or coil manometers for example are well known in the field. The information received from the temperature monitor 126 and the pressure monitor 128 is fed to the controller 122 through the inputs 120. The monitor 122 in turn adjusts the temperature and the pressure in the reaction zone 14 in the control chamber. reaction 1 12 to be within the desired limits, by techniques well known in the art. The pressure in the reaction zone 14 is preferably adjusted to be a large part of the hydrocarbon and the solvent remains as liquids at the operating temperature. In the case of the oxidation of cyclohexane to adipic acid, pressures between 0.703 and 35.15 kg / cm2 were preferred, although they can vary from a few kg / cm2 to thousands of kg / cm2 under certain circumstances. During the loading of raw material, or after the desired charge has been completed, a gaseous oxidant begins to be introduced through the oxidant feed line 1 18. The gaseous oxidant preferably either oxygen or a mixture of oxygen with a substantially inert gas, such as nitrogen, carbon dioxide, noble gas, and the like. The partial pressure of oxygen is preferably 0.703 to 35.15 kg / cm2 which can vary widely outside this scale, depending on individual circumstances. The flow rate of the gaseous oxidant through line 18 is preferably suitably high in a form that prevents depletion of the oxidant in reaction zone 114. As the gaseous oxidant is introduced, the hydrocarbon begins to oxidize, releasing hot. The released heat can be removed by one or more cooling means, such as for example cooling coils inside the reactor. However, it is highly convenient to remove the heat of reaction by evaporating condensable material from the liquids of the reaction zone 1 14. Therefore, the hydrocarbon, cyclohexane for example together with the solvent, for example acetic acid and water with minor amounts of other condensables, formed during the oxidation process, evaporate and condense in the condenser 130. The condensed matter is then heated to reflux directly in the reaction zone 14, or more preferably is introduced to a decanter 132. In the decanter 132 , the hydrocarbon with some solvent (and a smaller amount of water) was separated in an upper liquid phase 134 and the water with a considerable amount of solvent, as mentioned above and a minimum amount of hydrocarbon, is separated into a liquid phase lower 136. No condensable gas (not condensable in condenser 1 30), such as oxygen, nitrogen, carbon dioxide and the like, which carry some hydrocarbon arburo, some solvent, some water, etc. , leaves the system for additional treatment and / or disposal. However, the recycling of at least partial gas gas is non-condensable, below the surface of the mixture in liquids in the reaction chamber 12, if desired it can also take place. In the place of the condenser 130 and the decanter 132, a distillation column directly connected to the reaction chamber 1 can be used. With the distillation column, the individual components of the condensable material can be separated very efficiently. The upper phase is preferably recycled to reaction zone 1 14, preferably in its entirety via lines 140 and 142. However, all or part of the upper phase 134 can be removed through line 144 for further treatment. The flow rates through these lines are controlled by the first valve 143, which in turn is controlled by the controller 122, through the outlets 124. The lower stage 136, which contains water with solvent, can be recirculated partially or completely to the reaction chamber 1 12 through the lines 146 and 148. It can also be totally or partially removed through the line 150 for further treatment and / or disposal and / or recycling of any stage of the system. The second valve 149, which controls the flow through the lines 146, 148 and 150 in turn is controlled by the controller 122 through the inlets 124. After the oxidation has reached a desired point of conversion of the hydrocarbon , determined by the analytical apparatus 152, which samples the reaction zone 14 along the line 152, a stream of flowable matter starts to leave the reaction zone 14 of the reaction chamber 12 through the line of flowable matter transfer 174. The flow regime of the flowable matter exiting the reaction chamber 12 through line 174 is controlled by controller 122 through inlets 124. A flow of stuffing material it enters the reaction zone 1 14 of the reaction chamber 1 12 through the liquid feed line 1 16 to fill materials consumed during the oxidation. The average flow rates of liquid matter, which enter and leave the device of the reactor 1 12, must be equal to each other volume form, so that the average volume of matter in the reaction chamber 12 remains substantially constant. The flowable material leaving the reaction chamber 12 through the line 174 is transferred to other steps of the reactor device 10 (not shown for clarity) for the separation of the oxidation product, such as adipic acid by example, recyclable material, by-products, etc. The equilibrium and a state at rest are achieved as oxidation proceeds and controlled by the controller 122. Keeping the rest of the conditions substantially constant, the degree of conversion can be increased or decreased by decreasing or increasing respectively the flow rates through of lines 1 16 and 174. According to the present invention, a state at rest has to be maintained in the presence of substantially a single liquid phase in addition to other requirements. One way to substantially achieve a single liquid phase is to program the controller in a way that takes the information from the analytical apparatus, compares it with a phase diagram, as explained below and causes changes that will substantially ensure a single liquid phase of the content of the analyte. the reaction chamber 1 12. The variables that are important for the maintenance of substantially a single liquid phase, can be selected among others, from a group consisting of temperature in the reaction zone, pressure in the reaction zone, gaseous oxidant flow, water feed rate, catalyst feed rate, hydrocarbon feed rate, solvent feed rate and a combination thereof. Under conditions in the state of rest, and substantially constant temperature in the reaction zone, pressure in the reaction zone, gaseous oxidant regime, catalyst feed rate, hydrocarbon feed rate and solvent feed regime, the Water feed can be used and adjusted in a way that substantially assures a single liquid phase. Under the conditions established above, there is a maximum water feeding regime on which a second liquid phase is produced. Therefore, the water feed rate has to be lower than this maximum in order to ensure the presence of substantially a single liquid phase. Although the diagrams can be multi-dimensional, the ternary diagrams, which correlate three components, can also be used if the other parameters remain constant. Also for different groups of specific parameters, the respective ternary phase diagrams according to the present invention can be used. Examples of said parameters may be temperature, catalyst level, etc. Examples of such ternary phase diagrams, shown in Figures 5 and 6, have been discussed above. In general, according to this invention, when said computer flowchart systems and / or diagrams and / or precipitation data of the catalyst, are used by the controller to operate the system and ensure that the reaction is carried out in a phase, the analysis of the composition of the reaction chamber can be carried out as described above and in the flow regimes of different allocations (including recycled material and / or operating pressure) it can be changed accordingly to produce mixtures that they substantially contain a liquid phase. A similar procedure can be followed from the diagrams produced at different temperatures so that temperature manipulations can produce the desired results. Therefore, for example, the various parameters can be changed to achieve the desired condition of a phase including, but not limited to,, temperature in the reaction zone, pressure in the reaction zone, gaseous oxidant flow rate, water feed rate, catalyst feed rate, hydrocarbon feed rate, solvent feed rate and a combination thereof . However, if all the parameters remained constant, then the water feed regime then becomes the critical parameter to substantially secure a single liquid phase. The water was preferably tested initially from decanter 132 and secondly by the addition of water not recycled for example through line 1 16. In order to determine the maximum amount of water allowed in the reaction zone 14 or the maximum flow rate of water entering the reaction zone 14, a different technique than one described above can also be used. According to this technique, the upper water level monitor is used. As mentioned above, a sample of the content of the reaction zone 14 of the reaction chamber 12 is transferred to the first cell 162 (FIG. 8) via the line 154 '. Preferably the sample fills the main part of the first cell, so that there is only a small free space above the liquid. It is important because only limited amounts of vapors can occupy the small space, thus avoiding the alteration of the composition of the underlying sample. The temperature of the sample in the first cell 162 preferably remains the same as the temperature within the reaction zone 1 14. Since the equilibrium state in equilibrium of the reaction zone 1 14 has been selected such that it contains only substantially one liquid phase room (without specifying the existence or not of a solid or gaseous phase), the sample in the first cell 162 also substantially contains a single liquid phase. However, if for some reason two phases are observed in the sample of the first reaction zone 1 14 contained in the first cell 162. The rate of water flow to the reaction zone 1 14 in steps decreases until a sample taken of the reaction zone indicates the existence of only substantially a single phase. As mentioned above, the water source is preferably the decanter 132, and only if the decanter 132 can not provide adequate amounts of water to the reaction zone 14, a different or additional water supply can be used. Nominally, in an example that refers to the case of a Plant that produces 90 million kg of adipic acid per year, with a cyclohexane feed of approximately 40%, a catalyst (cobalt (II) acetate tetrahydrate) fed from about 0.5 to 1%, and a conversion of cyclohexane to dibasic acids (adipic, glutaric and succinic) of about 30%, a water feed of about 1% (in addition to the crystalline water of cobalt acetate tetrahydrate (II) ), a pressure in the reaction zone of 2.8 kg / cm2, a ratio of recycled gas to flushed gas of 4/1, water (in excess of the crystalline water of cobalt acetate (II) tetrahydrate) in the zone of reaction 1 14 can vary from about 0.5% to 0% recycle of the lower phase in the decanter 132 to about 4% by weight of complete recycling of the lower phase of the decanter 132. The water content in the reaction zone 114 it rises moderately With increasing recycle of the lower phase to approximately 70-80% recycle, at which point the water content in the reaction zone 14 starts to rise with additional increases in condensed recycling of the lower phase. Although the water in the feed is 1%, a sufficiently high quantity of water with cyclohexane is evaporated azeotropically to bring the water level in the reaction zone 14 to a level of approximately 0.5%, when recycled water is not used, if water (recycled or not) is not fed into reaction chamber 12, the water level (in addition to the crystalline water of cobalt acetate (II) tetrahydrate) in reaction zone 14 falls approximately 0.2 to 0.3% by weight. The first detector 166, moving up and down in the direction of the dates A can detect a second liquid phase as described above and is shown in Figure 9. Initially, since only a single liquid phase exists substantially, no peak such as peak 176 is present in the graph of Figure 9. At this point a small amount of water is added to the contents of first cell 162 through line 154. "Aggregate water may enter the phase 136 of the decanter 132, which contains considerable amounts of solvent or as substantially pure water The contents of the first cell 162 are preferably maintained, substantially at the same temperature as the operating temperature in the reaction zone 1 14. Accordingly, the contents of the first cell 162 are thoroughly mixed with the water agressively, preferably by vigorous mixing or by stirring the first cell 162. After each incr. Water element that is added and mixed, for water increase, the first cell 162 is allowed to stand for a short time, preferably from J4 to 1 minute. The first detector 166 tracked the first cell 162, as described above, to determine if a second liquid phase has formed. If the first detector 166 does not detect the formation of a second liquid phase, a small new portion of water (which preferably has the lower phase 136 of the decanter 132 as a source) is added to the cell 162 through the line 254". The contents of the first cell 162 are again mixed thoroughly with the added water, preferably by vigorous mixing or vigorous shaking, the first cell 162. The first detected 166 tracks the first cell 162, as described above, to determine whether a second liquid phase has been formed.This procedure is repeated until a second liquid phase is detected by the presence of a peak 176 in the graph of Figure 9. At this point, the total amount of water (calculated as% of water by weight) present in the composition of the first cell 162, at the operating temperature, represents the maximum water level in the cell and in the reaction zone 1 14 for all purposes in which, and over which substantially a single liquid phase, it is transformed into two liquid phases. It is obvious that the smaller the amounts of water by addition, the greater the pressure of the maximum level that can be determined. Water additions that increase the level of water in the first cell by 0.2% by weight per addition are often preferred. However, this increase by addition can be said based on particular circumstances. If for example there is a relatively large space between the maximum level of water over which the maximum level of substantially one liquid phase is transformed to two liquid phases and the minimum level below which the minimum level of catalyst is precipitated, then the additions They can be large compared to additions when it is relatively small space. If the added water necessary for the formation of the second liquid phase is less than 10% by weight of the total water contained in the cell, then the maximum level of water is being reached and the water is preferably removed. Preferably, the added water necessary for the formation of a second liquid phase should be controlled to be greater than 20% by weight of the total water contained in the cell. This is real, not only with respect to the cell referred to above, but also to any type of technique for determining the maximum water level necessary in which the formation of a second liquid phase occurs. These techniques include, but are not limited to, computer calculations using phase diagrams, flowcharts, flowchart simulations. Energy balances, etc. , well known in the field. With respect to the term "approach", similar principles apply to other ingredients such as hydrocarbon and / or catalyst, for example, with respect to the percentages of additional ingredient required for a second liquid phase to form or for the catalyst to precipitate . Therefore, the level of hydrocarbon and / or catalyst (in which a second liquid phase is formed or the catalyst is precipitated) is achieved so that the additional 10% of hydrocarbon and / or catalyst is required in or on which forms a second liquid phase or the catalyst is precipitated. In order to determine the minimum level of water in the reaction zone 14, under which the catalyst is precipitated at a minimum level, a number of techniques is often used, such as for example taking a sample from the reaction zone and remove water by azeotropic distillation together with solvent and hydrocarbon, recycling the solvent and hydrocarbon back to the sample at the operating temperature of the reaction zone, continuing this process to the precipitation point of the catalyst, and analyzing the composition of the Although this process is capable of determining the minimum level of water, under which the minimum level of water catalyst is precipitated, it is somewhat annoying and complicated.According to this invention, a substantially improved and faster process is one that the monitor 156 is used, best shown in Figures 10 and 11 1. A sample of flowable material taken from the reaction zone 14 is introduced into the second cell 164 of the monitor 156 through line 156 ', in an amount occupying the majority of the volume of second cell 164 for the same reasons given with respect to first cell 162. At the operating temperature in reaction zone 14, an adequate amount of water is present so that catalyst precipitation does not occur and therefore the sample received in the second cell 164 is transparent (Figure 10). This fact is detected by the second detector 168. For some reason the catalyst is precipitated in the reaction zone 14, it is convenient to filter the precipitated catalyst and / or increase the water feed rate (as long as the formation of the second liquid phase does not occur with said increase in water feed), preferably from lower stage 136 of decanter 132 to avoid further precipitation. As mentioned above, it has been found that there is an unexpected precipitation of catalyst at elevated temperatures at low water levels and relatively high levels of hydrocarbon and catalyst in a single liquid phase region. It has also been found that a correlation between the temperature at and over which the catalyst undergoes precipitation and the level of water in and below which the catalyst undergoes precipitation. Therefore, the observation of temperature at which the catalyst is precipitated can be used as a guide to judge whether the water level has been adjusted in order to avoid catalyst precipitation. The temperature in the second cell 164 is initially maintained the same. that in the reaction zone 1 14. Then, it rises gradually, preferably at a rate of about 1 ° C per minute. If precipitation of the catalyst occurs within a predetermined elevation in temperature (the predetermined elevation depending on the nature of the reaction zone, the approximate composition at which the reaction is being carried out, the degree of control of the water level and other parameters that can easily be determined in each case), the minimum water level at which the catalyst is precipitated closely approached and the water supply has to be increased to avoid catalyst precipitation in the case of spontaneous decrease even lower in the water level or that there is an increase in the temperature in the reaction zone. The number of increments is also determined by considering the maximum water level in the reaction zone, determined by the upper water level monitor 154. Preferably the water feed must be increased in a manner that the water level in the reaction zone 14 reaches and remains close to an average level between the maximum water levels and minimum. However, under certain circumstances, it may be desirable for the water level to be closer to the maximum level under other circumstances, it may be desirable for the water level to remain closer to the minimum level. In the case where the rise in temperature is higher than 20 ° C for precipitation of the catalyst, correction at the water level is usually not required. For interspersed temperature elevations, care must be taken and the water level may rise in some way if the water level rise does not approach the maximum water level above which a second liquid phase forms. The precipitation of the catalyst at least makes the content of the second cell 164 turbid, if not substantially non-transparent, which is detected by the second detector 168 (Figure 11). In the case of turbidity or light absorbance measurements, the precipitation of the catalyst can be differentiated from the formation of the second liquid phase (and probable emulsification of one liquid phase into another liquid phase) by the fact that the catalyst can rise temperature, while a second liquid phase can be formed by decreasing the temperature. Therefore, in the first case, the transparent content of the cell can become turbid or absorbent of light upon raising the temperature, while in the latter case, the transparent content of the cell can become turbid or absorbent as the temperature decreases.

A method by which the predetermined elevation mentioned above in the temperature can be determined is exemplified and illustrated in Figure 12, which represents a graph, the X axis which is the water level at or below which the catalyst is precipitated and the Y axis is the temperature at which the catalyst is precipitated, in experiments described above and performed in a cell similar to the second cell 164. In this particular case, the amount of catalyst (cobalt (II) acetate tetrahydrate) present was 4%, water was indicated on the X axis, and the solvent (glacial acetic acid) plus hydrocarbon (cyclohexane) constituted the rest of the composition. The crystalline water of cobalt (II) acetate tetrahydrate was not included in the amount of water indicated by the X axis. The crystalline water is taken into account as part of the cobalt acetate tetrahydrate (I I). All percentages are by weight and are based on the total hydrocarbon plus solvent plus catalyst plus water. Line A corresponds to the ratio (by weight) of acetic acid to cyclohexane of 60:40, while line B corresponds to the reaction (by weight) of acetic acid to cyclohexane of 50:50. Although in this example only 4 components were present and considered, may be present, products, oxidation byproducts, as well as other additional components, without changing the method for all practical purposes. If now, for the purposes of an example, we assume that the concentration of water in the reaction zone 14 is 1% (excluding the crystalline water of cobalt acetate (II) tetrahydrate) in a given situation and the possible control of water level, or maximum deviation, is + 0.15%, the variation in water level can be as much as 0.85% to 1 .15%. This variation of the water level corresponds to approximately a variation of 4 ° C in the case of line A (weight ratio of acetic acid to cyclohexane of 60:40) or of approximately a variation of 6.5 ° C in the case of line B (weight ratio of acetic acid to cyclohexane 50: 50). Therefore, if the operator (or controller) obtains information from cell 164 of monitor 156 (Figures 10 and 11) that take more than about 4 ° C over the first temperature (temperature in reaction zone 14 and of the contents of cell 164) to cause the precipitation of catalyst in 164, in the case where the ratio of solvent to hydrocarbon is about 60:40, then the addition of water in the reaction zone is not necessary for Ensure that the catalyst will remain in solution. Similarly, in the case of line B, where the ratio of solvent to hydrocarbon is about 50:50, if the operator (or controller) obtains information from cell 164 of monitor 156 that takes more than about 6.5 ° C on the first temperature to cause precipitation of the catalyst in cell 164, then the addition of water in the reaction zone is not necessary to ensure that the catalyst will remain in solution. If the temperature rises are smaller than the temperature variations mentioned above for the catalyst to precipitate, then the minimum level of water, under which the catalyst is precipitated, and the water content in the reaction zone are approaching. It has to increase. Therefore, the controller 122 receives respective information from the first monitor 154 and the second monitor 156 and is processed after according to a predetermined program, causes the appropriate adjustments to the water supply (recycled or fresh feed) so that the level of the Water in the reaction zone 114 is controlled to be within a range between the maximum and minimum limits desired, as discussed above. The programming of the controlled ones is well known in the art. If it is possible that in some occasions, especially in the case of excessive amounts of hydrocarbon, such as cyclohexane for example, and the catalyst, such as cobalt (II) acetate tetrahydrate for example, the "maximum" level of water over which a single liquid phase is formed at the operating temperature, is actually lower than "minimum" level of water under which the catalyst is precipitated at operating temperature. On such occasions, the operation of the reaction zone can only be carried out at a water level below the maximum water level on which a second liquid phase is formed in the presence of the precipitated catalyst. In some way, it is convenient that the level of hydrocarbon is lowered or the level of the catalyst is lowered, or both, so that the level of water in which the catalyst precipitation occurs decreases and the level at which it is formed is increased. the second liquid phase.

In any case, when under a given set of conditions, the level of water at or below which the catalyst is precipitated is higher than the level of water which or on which a second liquid phase is formed, there is no scale of a liquid phase within which there is a liquid phase without precipitated catalyst. The present invention applies particularly well to cases where the hydrocarbon is cyclohexane, the solvent is acetic acid and the catalyst is cobalt acetate tetrahydrate (I I). The level of water at which the catalyst precipitation occurs decreases as the cyclohexane content and / or the catalyst content decreases. The level of water in which the formation of the second liquid phase occurs increases as the cyclohexane content and / or catalyst content decreases. Therefore, with the decrease in the cyclohexane content and the catalyst content, the space between the maximum water level, on which a liquid phase is substantially transformed to two liquid phases and the minimum level at which it is precipitated The catalyst at the minimum level is expanded and the water level adjustments are made easier. However, at the same time the reaction rate and reactivity decrease (reaction rate is defined as the hydrocarbon molar oxidation per unit time, and the reactivity defined as the reaction rate per total volume of mixture implied in the reaction) . Therefore, a commitment must be made depending on the particular circumstances.

The most vulnerable region, which can benefit greatly from the teachings of the present invention, corresponds to chaos wherein the ratio of cyclohexane to acetic acid ranges from about 30/70 to about 60/40. This is a very important scale for the direct oxidation of cyclohexane to adipic acid on an operating temperature scale of 80 ° to 120 ° C. At a level of cobalt (II) acetate tetrahydrate of about 4%, the following has been visually observed in a cell similar to the first cell 162 and the second cell 164, shown in Figures 8 and 8A, respectively, but which they lack the first detector 166 and the second detector 168, respectively. It should be noted that in all three cases (A), (B) and (C), the catalyst level was 4% by weight, based on the sum of the most solvent catalyst (acetic acid) plus hydrocarbon (cyclohexane) plus water (excluding the crystalline water of cobalt (II) acetate tetrahydrate, whose crystalline water is taken as part of the catalyst.All levels in these cases were calculated in the same way. (A) at 90 ° C: (1) a a ratio of cyclohexane to acetic acid from 60 to 40, a second liquid phase formed at about and about 0.1% of the water level, and the catalyst was precipitated at about and under the same water level; therefore, there is no a practical scale within which there is a single liquid phase without precipitated catalyst; (2) at a ratio of cyclohexane to acetic acid from 50 to 50, the catalyst precipitation was presented at a water level of approximately and below 0.1%, while forming a second liquid phase at a water level of approximately and about 1%; therefore the level of the water in a reaction zone could have to be controlled at a level higher than about 0.25% to avoid catalyst precipitation and a lower level of about 1% to avoid the formation of a second liquid phase; (3) at a ratio of cyclohexane to acetic acid from 40 to 60, catalyst precipitation did not occur even at a water level of 0%, while a second liquid phase was formed at a water level of approximately and more than 2%; therefore the water in the reaction zone could have to be controlled at a level below about 2% to avoid the formation of a second liquid phase without any problem of precipitation of the catalyst. (4) At a ratio of cyclohexane to acetic acid from 30 to 70, precipitation of the catalyst at a water level of 0% did not occur, while a second liquid phase was formed at a water level of approximately and more than 3%; therefore the water in a reaction could have to be controlled at a level lower than about 3% to avoid the formation of a second liquid phase without any problem of catalyst precipitation; (B) at 100 ° C (1) at a ratio of cyclohexane to acetic acid from 60 to 40, one a second liquid phase was formed at about and about 0.15% of the water level, while the catalyst was precipitated at about 0.6% low water of a two phase liquid system; therefore there is no scale within which there is a single liquid phase without precipitated catalyst; (2) at a ratio of cyclohexane to acetic acid from 50 to 50, the catalyst precipitation occurred at a water level of about and below 0.9%, while forming a second liquid phase at a water level of about and about 1.4%; therefore the water level in a reaction zone could have to be controlled to a level higher than approximately 0.9% to avoid catalyst precipitation and a lower level of approximately 1.4% to avoid the formation of a second liquid phase; (3) at a ratio of cyclohexane to acetic acid from 40 to 60, catalyst precipitation did not occur even at a water level of 0.1%, while a second liquid phase was formed at a water level of approximately and more than 2.3%; therefore the water in the reaction zone could have to be controlled at a level lower than approximately 0.1% to avoid precipitation of the catalyst and a lower level of approximately 2.3% to avoid the formation of a second liquid phase; (4) at a ratio of cyclohexane to acetic acid from 30 to 70, precipitation of the catalyst at a water level of 0% did not occur, while a second liquid phase formed at a water level of about and more than 4.1%; therefore the water in a reaction could have to be controlled at a level lower than about 4.1% to avoid the formation of a second liquid phase without any problem of catalyst precipitation; (O at 1 10 ° C: (1) at a ratio of cyclohexane to acetic acid from 60 to 40, a second liquid phase was formed at about 0.2% of the water level, and the catalyst was precipitated at about and below 0.8 of water from a two-phase liquid system, therefore there is no scale within which there is a single liquid phase without precipitated catalyst, (2) at a ratio of cyclohexane to acetic acid from 50 to 50, the precipitation of catalyst at a water level of approximately and below 1.4%, while forming a second liquid phase at a water level of about and about 1.9%, hence the water level in a The reaction zone could have to be controlled at a level higher than about 1.4% to avoid catalyst precipitation and a lower level of about 1.9% to avoid the formation of a second liquid phase; ratio of cyclohexane to acetic acid from 40 to 60, n or catalyst precipitation occurred even at a water level of 0.8%, while a second liquid phase was formed at a water level of approximately and more than 3.2%; therefore the water in the reaction zone could have to be controlled at a level below about 3.2% to avoid the formation of a second liquid phase without any problem of precipitation of the catalyst. (4) At a ratio of cyclohexane to acetic acid from 30 to 70, precipitation of the catalyst at a water level of 0.2% did not occur, while a second liquid phase formed at a water level of approximately and more than 5.6%; therefore the water in a reaction could have to be controlled at a lower level than approximately 5.6% to avoid the formation of a second liquid phase without any problem of catalyst precipitation; (5) at a ratio of cyclohexane to acetic acid from 20 to 80, catalyst precipitation did not occur even at a water level of 0%, while a second liquid phase was formed at a water level of about and more than 8%; therefore the water in the reaction zone could have to be controlled at a level below about 8% to avoid the formation of a second liquid phase without any problem of precipitating the catalyst. However, it should be understood that in any case of the determination of the maximum or minimum water levels described above, samples must be taken manually and / or visually examined to detect the formation of two liquid phases and / or catalyst precipitation. and the results of said determination are fed to the controller 122 or the manually changed alienations.

Returning to Figure 8, the monitor 154 can be used for other purposes in addition to determining the maximum level of water on which a second liquid phase is formed. As mentioned before, the monitor 154 can be used to determine the maximum level of water on which a second liquid phase is formed. However, it can also be used to predict the formation of a second liquid phase under many other circumstances involving ingredients other than water. Therefore, in a different embodiment of the present invention, a sample of flowable material is transferred from a reaction zone 14 to the first cell 162, and if it is maintained at the same temperature at the same zone operating temperature. of reaction 1 14. In sequence, after it is added and mixed at each hydrocarbon increment, first cell 162 is allowed to stand for a short period, preferably from Vi to 1 minute and the first detector tracks the cell as described previously to detect if a second liquid phase has been formed. Depending on the amount of hydrocarbon added to form a second liquid phase the operator, or the controller program can predict if adjustments are made to the hydrocarbon feed or even to other allocations or other conditions, in order to ensure maintenance of substantially a liquid phase in the reaction zone 1 14. Preferably, if less than 3% by weight is increased in the concentration of hydrocarbons (based on the total content the first cell 162) the formation of a second liquid phase is caused, preferably, immediate action is taken to avoid the possible eminent formation of a second liquid phase in the second reaction zone. If, for example, the total content of the first yield 162 is X grams, the preferred maximum hydrocarbon addition causing the formation of a second liquid phase (before any action is taken) could be 3X (100-3) = 3X / 97. The type of action, for example, can decrease the hydrocarbon, such as cyclohexane for example, in the reaction zone, decrease the water level in the reaction zone, decrease the catalyst, for example such as cobalt acetate tetrahydrate ( II), in the reaction zone, increase the solvent, for example such as acetic acid, in the reaction zone, increase the operating temperature in the reaction zone, etc. In still a different embodiment of the present invention, a sample of the flowable material from the reaction zone 14 is transferred to the first cell 162 and maintained at the same temperature as the operating temperature of the reaction zone 14. In the sequence, small amounts of catalyst, for example cobalt acetate (II) tetrahydrate, are increasingly added to the first cell 162 and mixed well with their content. After each increment mixing catalysts are added, the first cell 162 is allowed to stand for a short period, preferably 1 to 1 minute and the first detector tracks the cell as previously described to detect whether a second liquid phase has been formed. Depending on the amount of catalyst added so that a second liquid phase is formed, the operator, or the controller program, can decide whether to adjust the hydrocarbon feed, or even another feed, or other conditions, in order to ensure the maintenance of substantially a single phase. Preferably, if less than 0.5% by weight increases the catalyst (based on the total content of the first cell 162) it causes the formation of a second liquid phase, preferably an immediate action should be taken to avoid the eminent possible formation of a second phase. liquid The type of action may be, for example, to reduce the hydrocarbon, such as, for example, cyclohexane, in the reaction zone, to decrease the level of water in the reaction zone, to decrease the catalyst, such as, for example, cobalt acetate tetrahydrate. (II), in the reaction zone, increase the solvent, for example such as acetic acid, in the reaction zone, increase the operating temperature in the reaction zone, etc.

Furthermore, in another embodiment of the present invention, a sample of flowable material from the reaction zone 14 is transferred to the first cell 162 and is initially maintained at the same temperature as the operating temperature of the reaction zone 14. In sequence, the content temperature of the first cell 162 gradually decreases, preferably at a rate of about 1 ° C per minute. If the formation of a second liquid phase occurs within a predetermined decrease in temperature, preferably 5 ° C, immediate action is preferably taken to avoid the eminent possible formation of a second liquid phase. The type of action can be, for example, to reduce the hydrocarbon, such as, for example, cyclohexane, in the reaction zone, to decrease the water level in the reaction zone, to decrease the catalyst, such as, for example, cobalt acetate tetrahydrate. (II), in the reaction zone, increase the solvent, such as for example acetic acid, in the reaction zone, increase the operating temperature in the reaction zone, etc. In the case where the decrease in temperature is greater than 20 ° C for the formation of a second liquid phase, a correction is usually not required. Care is required for intermediate temperature decreases for the formation of a second liquid phase. In another embodiment, the effect of adding more than one water, hydrocarbon, catalyst and solvent, in desired quantities through line 154", can also be determined and the information used, if desired, which will be fed to the controller 122 for further processing and action More than one cell of the type of first cell 162 may be used so that the effect of additional water, hydrocarbon, catalyst, etc., in the formation of a second liquid phase can be determined faster The effect of solvent in one or more cells to be determined, if the solvent is added before or after the formation of the second liquid phase in the cell.The similar results can be achieved by changing the temperature up and / or down.

Of course, any combination of one or more hydrocarbon, solvent, catalyst, initiator, other material, etc., (without entering the reaction zone) can be used in the first cell 162 of Figure 8, at a desired temperature , for the detection of the presence of a second liquid phase. In addition, the formation of a second liquid phase, at a desired temperature, by the addition of any combination of one or more hydrocarbon, solvent, catalyst, water, initiator, other material, in the first cell 162, containing a mixture of one Single pre-existing liquid phase of the components (eg hydrocarbon, solvent, catalyst, water, initiator, other material, etc.), can be observed and / or studied. In addition, any combination can be examined for the temperature at which a second liquid phase can be formed by varying the temperature of the first cell. Similarly, by raising the temperature in cell 163 of a lower temperature at which the catalyst is soluble, at a desired higher temperature a catalyst precipitation temperature can be determined, if said temperature exists within the range of the temperature lower than that of the temperature. desired upper temperature. As mentioned above, the present invention also pertains to a method for maintaining in a reaction zone, for example reaction zone 114, a mixture of substantially a single liquid phase comprising a hydrocarbon at a first hydrocarbon level, a catalyst to a first level of catalyst, a solvent to a first level of solvent and water to a first level of water, the method comprising the steps of: (a) contacting the liquid mixture, at least part of which enters the reaction zone, the reaction zone 1 14 for example, through line 1 16 for example, with a gaseous oxidant entering the reaction zone 1 14 through line 118 for example, the temperature in the zone of reaction being the first temperature, suitably high for oxidation to proceed; (b) taking a sample from reaction zone 14 in a cell 162 for example; (c) decreasing the temperature of the sample to a second predetermined temperature and if a second liquid phase (detected by the scanning detector 166 for example) is formed at a critical temperature in the scale between the first and second temperature; whether the reaction zone decreases for example in reaction zone 14, the first level of a component selected from a group consisting of hydrocarbon, water, catalyst and a mixture thereof to a degree that in a new sample, not form a second liquid phase on the scale between the first and second temperature, or increase in the reaction zone the first level of solvent to a degree that in a new sample does not form a second liquid phase on the scale between the first and second temperature, or increase in the reaction zone the first temperature to a third temperature at least by the difference between the critical temperature and the second temperature, or a combination thereof. In one example, if the first temperature in the reaction zone is 100 ° C, the second predetermined temperature is 95 ° C, and the formation of the second liquid phase occurred at a critical temperature of 98 ° C, the first temperature it should rise to be higher than 103 ° C (100 + 98-95). The raising of the first temperature to the third temperature is undesirable in the event that the catalyst is precipitated on the scale between the first and the third temperature. It should be understood that according to the present invention, any liquid or gas or natural gas, can be recycled totally or partially from any section to any other section. According to the present state of the art, after the reaction has taken place in the di-straight Synthesis of cyclohexane to adipic acid, two liquid phases are present at ambient temperatures or lower or together with a solid phase consisting mainly of acid adipic The two liquid phases have been called the "Polar Phase" and the "Non-Polar Phase". The two phases are decanted and the adipic acid is further crystallized and separated from the "Polar Phase". The presence of two liquid phases mixed with a solid phase and the precipitation acid of the "Polar Phase" together with the required filtration of the solid phase, causing a very undesirable situation. Decanting itself is an undesirable additional step in a process although it is carried out in the absence of a solid phase. The simultaneous presence of a solid phase, especially if part of the solid dissolves in one or more of the liquid phases and are apt to be precipitated by the decrease in temperature or with time, brings serious complications. The inventors of the present invention have discovered that they can prevent the formation of a two-phase liquid system and maintain a single liquid phase containing the solid phase, at room temperature or below using the techniques and devices described below in detail. The process of a second liquid phase not only eliminates the decantation step, but also simplifies the entire process of separating the solid phase from the single liquid phase. In addition to the formation of adipic acid, the methods of the present invention can also be applied to other dibasic acids from the corresponding cyclic aliphatic hydrocarbons. Examples are formation of glutaric acid of cyclopentane, formation of pimelic acid of cycloheptane and the like. Referring now to Figure 13, a device or reactor system 210 is described according to a preferred embodiment of the present invention. The system device or reactor 210 comprises a first reaction chamber 212.

The first reaction chamber 212 is connected to a first condenser 21 1, which in turn preferably is connected to a first retention chamber 213. The first retention chamber 213, also plays a role of a decanter, to separate, for example , water of reaction and / or solvent of hydrocarbon passage lines 215 and 217, for example respectively. Any type of capacitor can be used with the various chambers of the present invention, including but not limited to spray condensers, shell and tube heat exchangers, etc. A number of controlled feed lines or feed means are connected to the first reaction chamber 212. These lines or controlled feed means are a first hydrocarbon feed line 214i, a first gaseous oxidant feed line 214ii, a first solvent feed line 214i, a first catalyst feed line 214iv and a first starter feed line 214v. The feeding of the respective materials through these lines or controlled power supply means is controlled by a controller 215, having inputs 218 and outputs 220. The flow rate information of each power line is provided to the controller 216 by flow meters (not shown for clarity purposes) connected to the inputs 218 by techniques well known in the art. The valves or pumps, or a combination of both, (not shown for clarity purposes) are connected to the respective outputs 220, through which the controller 216 controls the feed rates of different streams after processing the information of the flow regimes as well as additional formation, such as temperature, pressure, analytical data, etc. , according to a desired program. The feeding lines mentioned above can be fused individually or together, in part or totally, to the pre-reaction chambers (not shown) or vessels (not shown), or exchangers (not shown), all well known in the art, before They enter the first reaction chamber 212. Said arrangements can also be controlled by the controller 216 through the output lines 220. A temperature monitor 222 and a temperature monitor 222 are also connected to the first reaction chamber 212. pressure 224, both connected (not shown) in turn to the input lines 218 of the controller 216. The temperature input obtained by the controller 216 is useful for various heat exchangers (not shown), such as heaters and / or coolers (including condensers) for example, either directly connected to the first reaction chamber 212, or through the lines 230, or through any arrangement of the lines 214i to 214v, which will be controlled by the controller 216 through the outputs 220 and thus adjust the temperature in the first reaction chamber. This combination provides an example of a first temperature control means for controlling the temperature inside the first reaction chamber 212. The pressure input obtained by the controller 216 is useful for various valves and / or pumps, etc. (not shown) which will be controlled by the controller 216 through the outputs 220 and thus adjust the pressure in the first reaction chamber according to a predetermined manner. This combination provides an example of a first pressure control means for controlling the pressure inside the first reaction chamber 212. Preferably, a chemical analysis monitor 226 is also connected to the first reaction chamber 212 to receive samples of the content of the reaction chamber. the first reaction chamber 212, analyzing them and providing the analysis information to the controller 216, again through the input lines 218. The chemical analyzer 226 preferably comprises instrumentation of CGT and LAR and more preferably CGT / MS, CGT / FID, LAR / UV and LAR / MS, to obtain fast and accurate chemical balances that will be provided to the controller 216 in order to be used for further processing and finally to be used for the control of the various parameters and conditions involved in the operation of the first reaction chamber 212. Also preferably, a phase analyzer or monitor 228, as described above, is connected to the first reaction chamber 212, to receive samples of the contents of the first reaction chamber 212, analyzing its phase and providing the analysis information to the controller 216, again through the input lines 218. The results are then provided to the controller 216 in order to be used for further processing and finally to be used for the control of the conditions of liquid phase inside the first reaction chamber 212. A natural gas outlet 230 is also connected to the first holding chamber od. chamber 213 for removing natural gases by techniques well known in the art. The first reaction chamber 212 communicates with a second chamber 232 through a first transfer line 234, whose first transfer line 234 comprises a valve 235. Preferably, a second temperature monitor 236, a second pressure monitor 238, a second chemical analyzer 241, and a second phase analyzer 243 are connected to the second container 232. In a similar way as in the case of monitoring different parameters of the first reaction chamber 212, second temperature monitor 236, second pressure monitor 238, second chemical analyzer 241 second phase analyzer 234 are connected to inputs 218 to provide information and allow controller 216 to control the respective parameters and content conditions of the second chamber 232. Therefore, they provide means for controlling the second temperature and the second pressure in the second chamber 232, while maintaining a single liquid phase.

Although for continuous reactor systems, the first reaction chamber 212 and the second chamber 232 should be individual units, in the case of batch reactors, they can be combined in one and the same unit, preferably using only one group of monitors and analyzers The second chamber 232 is also connected to a second condenser 240, which in turn is preferably connected to a second holding chamber 242. The second holding chamber 242 can also play the role of a decanter, to separate, for example, water of the reaction and / or for example, solvent of the main hydrocarbon through lines 244 and 246, respectively. A vacuum generator V2 can also preferably be connected to the second holding chamber 242. The second chamber 232 preferably is further connected to the separation means, such as for example a solids separator 248, to at least partially remove the acid. dibasic Said solids separators for example can be pressure filtration devices, centrifuge devices, etc. The solids can be transferred out of the solids separator 248 through a line of solids 250 and the liquids can be transferred out of the solids separator 248 through a liquid line 252. A second hydrocarbon feed line 254 preferably is provided with a flow meter which gives flow information to the inlet 18 of the controller 216 and is connected to the second chamber 232. Preferably it originates from a hydrocarbon supply vessel (not shown) through the pumps and / or valves (not shown), which are connected to the output lines 220 and controlled by the controller 216. The hydrocarbon, such as for example cyclohexane, can be supplied to line 254 from line 246 or any other line or source appropriate In operation of this embodiment, the hydrocarbon, such as cyclohexanone, for example, enters the first reaction chamber 212 through the hydrocarbon feed line 214L The gaseous oxidant, such as oxygen or a mixture of oxygen with an inert gas , for example, enters the reaction chamber 212 through the gaseous oxidant feed line 214ii. The solvent, such as for example acetic acid, enters the first reaction chamber 212 through the solvent feed line 214iii. The catalyst, such as for example a cobalt compound, enters the first reaction chamber 212 through the catalyst feed line 214iv. The initiator, such as for example acetaldehyde or cyclohexanone, enters the first reaction chamber 212 through the feed line of the initiator 214v. As mentioned before, feeding the raw material above does not have to take place directly in the reaction chamber 212. Some or all of the raw material can be pre-mixed, pre-heated, pre-cooled, or somehow treated before entering the raw material. reaction chamber 212, by techniques well known in the art, or as described in our patents and patent application mentioned above. The mixtures of products and / or recycled by-products, they can also be introduced into the reaction chamber 212, individually or combined with one or more of the raw materials, then no additional feed is necessary. The first temperature and the first pressure are arranged by the controller to be such that a hydrocarbon reaction, for example cyclohexane, an oxidant, for example oxygen, takes place in a controlled manner. The first preferred partial pressures of the oxidant are on the scale of 0.703 to 35.15 kg / cm2 and the first temperatures on the scale of 60 ° C to 160 ° C. These preferred scales, however, depend on the nature of the hydrocarbon and oxidant. In the case where the hydrocarbon is cyclohexane and the oxidant is oxygen, the preferred scale of the first temperatures is 80 ° C to 120 ° C. A still more preferred scale is 90 ° C to 1 10 ° C. It is highly desirable that the content of the reaction chamber 212 comprises a single liquid phase. The chemical analyzer 226 and / or the phase analyzer 228 gives the information to the controller 216, which is used to ensure the condition of a single liquid phase, if desired. Although it is preferable that it does not have suspended solids in this stage, the existence of a solid phase suspended within the single liquid phase or even double liquid phase is not excluded. Preferably, part of the contents of the first reaction chamber 212 is being transferred to the second chamber 232 through the first transfer line 234, where it is being cooled to a second temperature, lower than that of the first temperature of the first one. reaction chamber 212. At the second temperature, precipitation of the oxidation product, such as for example adipic acid, is preferably present. The second temperature is preferably room temperature (approximately 20 ° C) or lower, but not lower than the freezing point of the solids content of the second chamber 232. The second temperature is monitored by the second temperature monitor 236 and the temperature information the controller 216 is provided for further processing. In some instances, such as in the case of for example atomization reaction chambers, it is also preferred that another part of the contents of the reaction chamber 212 be recycled (not shown) from line 234 back to the first chamber of reaction 212, preferably through atomization nozzles. According to the present invention, it is also necessary that despite the fact that the second temperature is lower, and preferably considerably lower, than the first temperature, the second liquid phase is not allowed to form. If a second phase is not allowed to form, an undesirable decant step, especially in the presence of a solid precipitated phase, and its consequences, is completely eliminated. The second temperature can be controlled in a number of different ways. A highly preferable way is to controllably reduce the pressure in the second chamber 232 to obtain a preference value considerably lower than the value of the first pressure prevailing in the first reaction chamber 212. In doing so, two very convenient phenomena take place. First, the temperature is being decreased by evaporation of volatiles, such as cyclohexane or for example another hydrocarbon, due to the reduction of pressure. Secondly, the hydrocarbon evaporation results in a decrease in the hydrocarbon content in the mixture, which favors a single liquid phase. The decrease in hydrocarbon content must be high enough to maintain the only liquid phase at the second temperature. If the initial content of the first reaction chamber 212 is sufficiently low and / or if the conversion of hydrocarbon to dibasic acid is sufficiently high, then there is no need for high amounts of content of the second chamber 232 to be removed with the order to maintain a single liquid phase. In that case, additional still cold hydrocarbon or other raw material can be added to the second chamber 232 through the second hydrocarbon feed line 242 without formation of a second liquid phase. Said matter may preferably be solvent or hydrocarbon. The hydrocarbon evaporated from the second chamber 232 together with solvent, water and other gases and / or vaporized liquids is condensed in the second condenser 240, and is recovered in the second holding chamber 242, where the water with solvent can be separated from the hydrocarbon with solvent and, in either or both, it is recycled (for example to the first reaction chamber 212 or to the second reaction chamber 232) or is treated in some way through the lines 244 and 246. Additional cooling can be provided, if necessary, to the contents of the second chamber 232, by techniques well known in the art, so that at least part, and preferably the majority of the dibasic acid, for example adipic acid, is precipitated. In contrast, the dibasic acid is separated in the solids separator 248, for example by filtration, or any other method well known in the art. The solids were transferred out of the solids separator 248 through the line of solids 250 and the liquids are transferred out of the solids separator 248 through the liquid line 252 for further treatment and / or recycling. The temperature of the second chamber 232 can also be handled by adjusting the composition to the contents of the second chamber 232. For example, heat can be added with simultaneous adjustment of hydrocarbon content, such as for example cyclohexane. The removal of water with cyclohexane favors the formation and maintenance of a single liquid phase. For example, recycle of the cyclohexane from the second holding chamber 242 to the second 232 through the line 246 and the simultaneous addition of heat to said second chamber 232 by means of a heating coil (not shown) for example, can decreasing the water and / or cyclohexane content in the second chamber 232 and thus promoting the formation and maintenance of a single liquid phase. In addition, the addition of solvent also favors the formation and maintenance of a single phase. The second pressure inside the second chamber 232 is preferably maintained as atmospheric or subatmospheric through the vacuum generator V2. In some instances, additional cooling in the second chamber 232 may be achieved by the addition of hydrocarbon or other matter having a temperature lower than the temperature of the contents of the second chamber 232, through line 254, as also mentioned before. As mentioned, in a similar way as in the case of monitors of the different parameters of the first reaction chamber 212, the second temperature monitor 236, the second pressure monitor 238, the second chemical analyzer 241, the second analyzer of phases 243, and the flow meters on lines 234 and 254 are connected to the inputs 218 to provide information and allow the controller 216 to control the respective parameters and content conditions of the second camera 232. Therefore, they provide means for controlling the temperature and pressure in the second chamber 232, while maintaining a single liquid phase. In a different preferred embodiment of the present invention, better illustrated in Figure 14, the reactor system 210, comprises, in addition to the other chambers and their accessory elements, a first intermediate chamber 256, which communicates with the first reaction chamber 212 through the first transfer line 234, and with the second chamber 232 through a second transfer line 258. To the first intermediate chamber 256, a first intermediate temperature monitor 260 is also connected, the which is also connected to the inputs 218 of the controller 216 to provide temperature information in the controller, which in turn controls the temperature inside the chamber 256. This arrangement constitutes the first intermediate temperature control means for controlling the temperature in the first intermediate chamber 256. To the first intermediate chamber 256, a first monitor is also connected intermediate pressure 262, whose monitor is also connected to the inputs 218 of the controller 216 to provide pressure information to the controller, which in turn controls the pressure inside the chamber 256. This arrangement constitutes the first intermediate pressure control means to control the temperature in said first intermediate chamber 256. The intermediate chamber 256, further comprises the first intermediate external heating means 264, such as for example the heating coil, to provide thermal energy to the material inside the first intermediate chamber 256 The intermediate chamber 256 is also connected to an intermediate capacitor 266, which in turn preferably is connected to an intermediate retention chamber 268. As in the case of the retainer 242, the retainer 268 can also serve as a decanter to separate the water of reaction and / or the solvent through the line 270 and mainly the hydrocarbon through line 272. An intermediate vacuum generator V3 can also be connected to intermediate holding chamber 268. Decanting liquids in the absence of a solid phase are substantially less complicated than decanting in presence of said solid phases. The operation of this embodiment is similar to the operation of the previous embodiment with the exception that the first pressure prevailing in the first reaction chamber 212 is controllably reduced to a first desired intermediate pressure in the intermediate chamber 256, forcing the hydrocarbon and smaller amounts of other non-volatile materials, such as for example water and / or reaction solvent, to evaporate and concentrate by the intermediate condenser 266, thereby lowering the hydrocarbon content in the first intermediate chamber 256 and also removing the heat of the system, resulting in the decrease of the first intermediate temperature. In a continuous operation which is the preferred type of preferred operation, a liquid stream from the first reaction chamber 212 is being transferred to the first intermediate chamber 256 through the first transfer line 234. The first means of intermediate external heating 264, provide a controlled and desired amount of heat to the contents of the first intermediate chamber 56, so that the hydrocarbon is further evaporated. The temperature and hydrocarbon content of the first intermediate chamber 256 can be maintained at such levels so that substantial precipitation of a solid phase comprising dibasic acid is preferably not present. Higher temperatures and lower hydrocarbon content favor the prevention of precipitation, as well as the prevalence of a single liquid phase. A liquid stream is also being transferred to the second chamber 232 through the second transfer line 258. The remainder of the operation is substantially the same as described in the previous embodiment, with the controller programmed to ensure that the second The temperature prevailing in the second chamber 232 and the amount of hydrocarbon are such that there is only one liquid phase containing the precipitated dibasic acid, for example adipic acid. In still a different preferred embodiment of the present invention, best illustrated in Figure 15, the reactor system 210, comprises, in addition to the other chambers and their accessory elements, a second intermediate chamber 274, which communicates with the first intermediate chamber 232 through the second transfer line 258, and with the second chamber 232 through a third transfer line 276. Although, for simplicity, the capacitors, which retain the cameras, vacuum generators, etc. , they are not shown in all the cameras, it should be understood that said elements can be connected to any of the cameras. In addition, one or more of the vacuum generators can be replaced by descending valves, open liners, etc. To the second intermediate chamber 274, a second intermediate temperature monitor 278 is also connected, which monitor is also connected to the inputs 218 of the controller 216 to provide temperature information to said controller, which in turn controls the temperature inside the chamber 274. This arrangement constitutes second intermediate temperature control means for controlling the temperature in the second intermediate chamber 274. To the second intermediate chamber 274, the second intermediate pressure monitor 280 is also connected, which is also connected to the inlets 218 of the controller 216 to provide pressure information and the controller, which in turn controls the pressure inside the chamber 274. This arrangement constitutes the second intermediate temperature control means for controlling the temperature in the second intermediate chamber 274. The second intermediate chamber 274, further comprises the second ex cooling means intermediate layers 282, such as for example a cooling coil, for removing the thermal energy of the material inside the second intermediate chamber 274.

The operation of this mode is similar to the operation of the previous modes except that the first intermediate temperature prevailing in the first intermediate chamber 56 is reduced in the second intermediate chamber to a second intermediate temperature substantially without precipitation of solids. After the addition of heat and removal of an adequate amount of hydrocarbon in the first intermediate chamber 256, heat is removed in the second intermediate chamber 274, so that when the second intermediate pressure, which is preferably equal to the first intermediate pressure , is reduced in the second chamber 232 to the second pressure, the temperature suitably decreases so that a substantial precipitation of the dibasic acid, for example adipic acid, occurs. Of course, an adequate amount of hydrocarbon, for example cyclohexane, is removed in the first intermediate chamber 256 and the second chamber 232, so that the second liquid phase is not formed in the second chamber 232. It is highly convenient to avoid having elements of cooling, such as for example cooling coils, in the chamber (in this case the second chamber 232) in which the precipitation of the solid phase takes place, since it is deposited on the coils and the problems of clogging become a problem serious. Chemical analyzes and / or phases can be carried out on the contents of any transfer line and / or any of the cameras in any of the modalities.

It should be understood that according to the present invention, the liquids or gases or natural gases of any chamber can be totally or partially recycled to any other chamber. A preferable type of controller is a computerized controller and more preferably a "learning computer" or a "neuro-computer", the functionality of which is known in the art and which collects information from different places on the device (e.g. pressure, temperature, chemical analysis and others, etc.), stores this information together with the result (reaction regime, for example), and was programmed to use this information in the future, along with other data if applicable, to take decisions regarding the action that will be carried out in each case. Although the various functions are preferably controlled by a computerized controller, it is possible, in accordance with this invention, to use any other type of controller or even manual controls to control one or more functions. Oxidations according to this invention are non-destructive oxidations, wherein the oxidation product is different than carbon monoxide, carbon dioxide and a mixture thereof. Of course, small amounts of these compounds can be formed together with the oxidation product, which can be a product or a mixture of products.

Examples include, but of course, are not limited to the preparation of C5-C8 aliphatic dibasic acids of the corresponding saturated cycloaliphatic hydrocarbons, such as, for example, the preparation of cyclohexane adipic acid. Other examples include, but are not limited to, the formation of benzoic acid, phthalic acid, isophthalic acid, toluene terephthalic acid, ortho-xylene, meta-xylene and para-xylene, respectively. With respect to the adipic acid, the preparation of the cuai is especially suitable for the methods and devices of this invention, the general information can be found in a plethora of the Patents of E.U.A. among other references. These include, but are not limited to, the Patents of E. U.A. 2,223,493; 2, 589,648; 2,285, 914; 3,231, 608; 3,234,271; 3,362, 806; 3,390, 174; 3, 530, 185; 3,649,685; 3,657,334; 3,957,876; 3, 987, 100; 4,032, 569; 4, 105, 856; 4, 158,739 (glutaric acid); 4,263,453; 4, 331, 608; 4,606, 863; 4, 902, 827; 5, 221, 800; and 5,321, 157. Examples have been given demonstrating the operation of the present invention, solely for purposes of illustration, and should not be construed as limiting the scope of this invention in any way. Furthermore, it should be emphasized that preferred embodiments discussed hereinafter in detail, as well as any other modality encompassed within the limits of the present invention, may be practiced individually, or in any combination thereof, according to the sense common and / or expert opinion. The individual sections of the modalities may also be practiced individually or in combination with other individual sections of the modalities or modalities in their entirety, in accordance with the present invention. These combinations also lie within the present invention. In addition, any explanation intended in the discussion are only speculative and are not intended to narrow the limits of the claims of this invention.

Claims

R EIVI N DICATION IS 1. A method for controlling in a first reaction zone the oxidation of a hydrocarbon selected from a group consisting of cyclohexane, o-xylene, m-xylene, p-xylene, and toluene to form an acid selected from a group consisting of adipic acid, phthalic acid, isophthalic acid, terephthalic acid and benzoic acid, respectively, in the presence of a catalyst, a solvent comprising acetic acid, an optional initiator, water and oxidation products; the hydrocarbon, the catalyst, the solvent and at least part of the oxidation products that form at least partially a mixture of liquids, in which the method of the liquid mixture is brought into contact with a gaseous oxidant in the first zone of reaction at a first temperature, the first temperature being suitably high for oxidation to proceed and in which the oxidation method is directed to a state at rest at a first level of hydrocarbon, a first level of solvent, a first catalyst level and a first level of water, wherein the improvement comprises the steps of: (a) controlling at least one of the first level of hydrocarbon, the first level of the solvent, the first level of the catalyst and the first level of water , in a manner that causes the formation and / or maintains a single liquid phase in the first reaction zone, regardless of the presence or absence of a solid phase and if necessary; and (b) making adjustments related to the phases of the liquid mixture, the adjustments related to phases being based at least partially on the phase formation ratios, wherein the liquid mixture is at a second temperature, and where The adjustments related to phases are directed to the formation and / or maintenance of a single liquid phase. A method as defined in claim 1, wherein the adjustments related to the phase for the mixing of liquids in the first reaction zone are carried out by a variable selected from a group consisting of temperature in the first zone of reaction, pressure in the first reaction zone, gaseous oxidant flow rate in the first reaction zone, water flow rate in the first reaction zone, water removal rate of the first reaction zone, flow rate of catalyst in the first reaction zone, hydrocarbon flow rate in the first reaction zone, hydrocarbon removal rate of the first reaction zone, solvent flow regime in the first reaction zone, solvent removal regime of the first reaction zone, flow regime of recycled natural gas in the first reaction zone and a combination thereof. 3. A method as defined in claim 1 or 2, further comprising a step for determining one or more of: a maximum hydrocarbon level, a maximum water level, and a minimum catalyst level, at or above which the only liquid phase is transformed to liquid phases; and a minimum solvent level, at or below which, the single liquid phase is transformed to two liquid phases; under a group of conditions, where the levels that are not determined remain constant. 4. A method as defined in claim 3, wherein the step of determining one or more of the levels, in or over which, the single liquid phase is transformed into two liquid phases, further comprises the steps of: obtaining a sample of a liquid mixture of the first reaction zone; and adding to the sample, hydrocarbon or water, or catalyst, or a combination thereof, until a second liquid is formed. 5. A method as defined in claim 4, wherein at least one of the first hydrocarbon level, the first water level, and the first catalyst level is controlled to be below the maximum hydrocarbon level, the water level maximum the maximum catalyst level, respectively, and the first level of solvent is controlled to stay above the minimum solvent level. 6. A method as defined in claim 4 or 5, further comprising a step of analyzing the sample to obtain composition data with respect to the sample. 7. A method as defined in claim 6, further comprising the steps of understanding the composition data of the sample with phase diagrams and making adjustments related to the phase in the first reaction zone, if the formation is approaching. of a second liquid phase. 8. A method as defined in claim 6, further comprising the steps of comparing the composition data of the sample with one or more of the maximum hydrocarbon level, the maximum water level, the maximum catalyst level and the Minimum solvent level and make adjustments related to the phase in the first reaction zone, if one or more of the maximum hydrocarbon level, the maximum water level, and is approaching the maximum catalyst level and the level of solvent minimum, respectively. 9. A method as defined in claim 1, 2, 3, 4, 5, or 6, wherein one or more of the first level of hydrocarbon, the first level of catalyst a first level of water is controlled to stay within of a majority scale, the majority scale being a scale between a high predetermined majority level and a predetermined low majority level, the high majority level being below a maximum level at or above which the maximum level is formed at a second stage, the low majority level being between the high majority level and an average of the maximum level and a minimum level, in and below which the catalyst precipitates at the minimum level. 10. A method as defined in claim 1, 2, 3, 4, 5, or 6, wherein the first level of water and / or solvent is controlled to remain within a minority scale, the minority scale being a scale between a low predetermined minority level, and a high predetermined minority level, the low minority level being higher than a minimum level at or below which the catalyst precipitates and the high minority level being between the low minority level and an average of the minimum level and a maximum level, in and above said maximum level a second phase is formed. eleven . A method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, wherein the first temperature is controlled by evaporating condensable volatile matter from the reaction zone and recycling at least part of the material volatile condensable to the reaction zone as it condenses. 12. A method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein the acid comprises adipic acid, the hydrocarbon comprises cyclohexane, the solvent comprises acetic acid, The catalyst comprises a cobalt salt and the optional initiator comprises a compound selected from a group comprising acetaldehyde, cyclohexanone and a combination thereof. 13. A method of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, further comprising: a step of controlling at least one level of the first level of water and the first level of solvent in a manner that is higher than a respective level, at or below which, the catalyst precipitates; and the first hydrocarbon level and the first level of catalyst that will be lower than a respective level, not on which the catalyst is precipitated. A method as defined in claim 13, comprising the steps of: taking a sample from the first reaction zone; decrease the temperature of the sample to a second predetermined temperature and if a second liquid phase is formed at a critical temperature in the scale between the first and second temperatures, then decrease in the first reaction zone the first level of the selected component of a group which consists of hydrocarbon, water, catalyst and a mixture of them to a degree that in a new sample does not form a second liquid phase in the scale between the first and second temperatures, or increase in the first reaction zone the first level of solvent to a degree that in a new sample a second liquid phase is not formed in the scale between the first and second temperatures, or to increase in the first reaction zone the first temperature to a third temperature at least by the difference between the critical temperature and the second temperature, or a combination thereof. 15. A method as defined in claim 13 or 14, wherein the control of the first water level within the upper and lower limits is based on the determination of the composition of the single-phase liquid mixture of the first zone of water. reaction, comparing said composition with the phase diagrams and precipitation data of the catalyst and adding water to the mixture of the single liquid phase in the first reaction zone if the lower limit is being reached or removing water from the first reaction zone if The upper limit is being reached. 16. A method as defined in claim 13, further comprising the steps of: taking a sample from the first reaction zone; confining the sample within a closed cell under adequate pressure to retain the sample in a substantially liquid form; raising the temperature of the cell of the first temperature to a higher temperature; and if the catalyst is precipitated within a predetermined elevation in temperature; raising the level of water or the level of solvent in the first reaction zone, or decreasing the level of hydrocarbon or the level of catalyst in the first reaction zone. 17. A method as defined in claim 13, further comprising the steps of: taking a sample from the first reaction zone; confining the sample within a closed cell under adequate pressure to retain the sample in a substantially liquid form; adding hydrocarbon to the sample to determine if the catalyst is precipitated before the formation of a second phase; and controlling in the first reaction zone the first hydrocarbon level which will be maintained at a lower level than the level required to cause precipitation of the catalyst at levels of solvent, catalyst, and water present in the cell. 18. A method as defined in claim 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 17, further comprising the steps of: decreasing the first temperature to a second temperature, while maintaining a single liquid phase at the second temperature; and remove at least part of the acid formed. 19. A method as defined in claim 18, further comprising the step of recycling at least part of one or more of the products, intermediates, by-products, reagents, solvents, natural gases and other existing ingredients either directly to the first reaction zone or indirectly after post-treatment, or a combination thereof. 20. A method as defined in claim 18 or 19, wherein the decrease in the first temperature at the second temperature is carried out at least partially by an operation selected from a group consisting of (a) evaporating by the least part of the hydrocarbon, (b) decrease the first pressure a second pressure, (c) add matter that has a temperature lower than the first temperature, (d) add volatile matter, (e) remove heat by external means, (f) ) removing a first amount of heat by any suitable means and adding a second amount of heat by external means, the first amount of heat being greater than the second amount of heat, and (g) a combination thereof. twenty-one . A method as defined in claim 18, 19 [or 20, wherein the maintenance of a single liquid phase at the second temperature is controlled by adjusting the level of hydrocarbon, or water, or solvent, or a combination thereof, at a second temperature. 22. A method as defined in claim 18, 19, 20 or 21, wherein the decrease of the first temperature to a second temperature is carried out in a second zone. 23. A method as defined in claim 18, 19, 20, 21, or 22, wherein lowering the first temperature to the second temperature involves an intermediate step of lowering the first temperature to a first intermediate temperature by decreasing the first temperature. pressure at an intermediate pressure to form a first intermediate liquid phase that does not contain a substantial amount of the solid phase. 24. A reactor device for oxidizing a hydrocarbon selected from a group consisting of cyclohexane, o-xylene, m-xylene, p-xylene, and toluene to form an acid selected from a group consisting of adipic acid, phthalic acid, isophthalic acid , terephthalic acid and benzoic acid, respectively, in the presence of a catalyst, a solvent comprising acetic acid, an optional initiator, water and oxidation products, the device comprising a first reaction chamber, a temperature monitor connected to the first chamber of reaction to measure the temperature inside the first reaction chamber, temperature control means connected to the first reaction chamber and the temperature monitor for controlling the first temperature, wherein the improvement comprises: phase detection means connected to the reaction chamber to detect in the reaction chamber at least a hydrocarbon level, solvent level, or catalyst level and water level and determine if a second phase is approaching or is formed inside the reactor; and phase control means to make adjustments related to the phase towards the maintenance or formation of a single liquid phase, adjusting at least one of the hydrocarbon level, the solvent level, the catalyst level, the water level and the first temperature, when a second liquid phase approaches or forms within the first reaction chamber. 25. A device as defined in claim 24, further comprising a controller, which instructs the phase control means for lowering the level of at least one hydrocarbon, the catalyst and the water, and / or raising at least one of the solvent level and the first temperature, when the second liquid phase approaches or forms within the first reaction chamber. 26. A reactor device as defined in claim 24 or 25, wherein the phase control means further comprises correlation means for correlating the phase diagram data with ingredients in the reaction chamber and adjusting the feed rates. from the ingredients to the reaction chamber to the formation in a single liquid phase. 27. A guiding device as defined in claim 24, 25, or 26, wherein the phase detection means provides information to the phase control means for adjusting the feed rates of the ingredients fed to the reaction to the formation or maintenance of a single liquid phase. 28. A reactor device as defined in claim 24, 25, 26 or 27, further comprising variable control means for controlling in the reaction chamber a variable selected from a group consisting of temperature in the first reaction chamber, pressure in the first reaction chamber, gaseous oxidant flow rate in the first reaction chamber, water flow rate in the first reaction chamber, water removal rate of the first reaction chamber, catalyst flow rate in the first reaction chamber, hydrocarbon flow rate in the first reaction chamber, hydrocarbon removal rate of the first reaction chamber, solvent flow rate in the first reaction chamber, solvent removal rate of the first reaction chamber, flow regime of recycled natural gas in the first reaction chamber and a combination thereof. 29. A reactor device as defined in claim 24, 25, 26, 27, or 28, further comprising: liquid feed means for at least partially supplying hydrocarbon, solvent, catalyst, optionally initiator and optionally water in the first reaction chamber; means for removing water to remove water from the first reaction chamber; gas feed means for feeding oxidant into the first reaction chamber; and means of controlling the water level to control the water level in the reaction chamber on a scale between a maximum water level, on which a single liquid phase is substantially transformed into two liquid phases and a minimum level at which the catalyst precipitates. 30. A reactor device as defined in claim 29, wherein the water level control means comprises means for detecting the water level to detect the placement of the water level with respect to the maximum level and the minimum level . 31 A reactor device as defined in claim 30, further comprising a controller connected to the water level sensing means for receiving information regarding the placement of the water level and using said information to adjust the water level in a water level. way to control the water level between the maximum level and the minimum level in the reaction zone. 32. A reactor device as defined in claim 30 or 31, wherein the water level sensing means comprises a temperature operated detector for detecting the placement of the water level with respect to the minimum level. 33. A reactor device as defined in claim 30, 31, or 32, wherein the means for detecting the water level comprises a detector operated by the addition of water to detect the placement of the water level with respect to the water level. maximum level. 34. A reactor device as defined in claim 30, 31, 32, or 33, wherein the water level control means comprises analytical water level detection means for detecting and / or determining the level of water level. water in the first reaction chamber and wherein the reactor device further comprises a controller connected to the analytical water level detection means for receiving information regarding the water level in the reaction chamber, comparing said information with the data of phase diagram and catalyst precipitation data stored in the controller and using the comparison to adjust the water level in the first reaction chamber in a way to control the water level between the maximum level and the minimum level. 35. A reactor device as defined in claim 29, 30, 31, 33, or 34, further comprising a distillation column connected to the first reaction chamber. 36. A reactor device as defined in claim 29, 30, 31, 32, 33, or 34, further comprising a condenser connected to the first reaction chamber and a decanter connected to the condenser. 37. A reactor device as defined in claim 30, 31, 32, 33, 34, 35, or 36, wherein the means of detecting the water level sensing means comprises a temperature operated detector for detecting the placement of the water level with respect to the minimum level. 38. A reactor device as defined in claim 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, or 37, further comprising: first temperature control means connected to the first reaction chamber to control the temperature in the first reaction chamber; first pressure control means connected to the first reaction chamber for controlling the pressure in the first reaction chamber; first hydrocarbon feed means connected to the first reaction chamber for feeding hydrocarbon into the first reaction chamber; first gaseous oxidant feed means connected to the first reaction chamber for feeding the gaseous oxidant into the first reaction chamber; a second chamber connected to the first reaction chamber; second temperature control means connected to the second chamber for controlling the temperature in the second chamber; second pressure control means connected to the second chamber for controlling the pressure in the second chamber; a controller to control various parameters in the cameras in a way that in the second chamber there is a single liquid phase. 39. A reactor device as defined in claim 38, further comprising a condenser or a distillation column connected to one or both of the first reaction chamber and the second chamber. 40. A reactor device as defined in claim 39, further comprising a retention chamber or decanter connected to the condenser. 41 A reactor device as defined in claim 39 or 40, further comprising: a first intermediate chamber that communicates with the first reaction chamber; first intermediate temperature control means connected to the first intermediate chamber for controlling the temperature in the first intermediate chamber; first intermediate pressure control means connected to the intermediate chamber for controlling the pressure in the first intermediate chamber; first intermediate external heating means to provide thermal energy to the material inside the first intermediate chamber; a capacitor connected to the first intermediate chamber; separating means connected to or being part of the second chamber to at least partially separate the dibasic acid from the mixture. 42. A reactor device as defined in claim 41, further comprising: a second intermediate chamber connected to the first intermediate chamber and the second chamber; Second intermediate cooling media can be used to remove thermal energy from the material inside the second intermediate chamber. 43. A reactor device as defined in claim 38, 39, 40 ', 41, or 42, further comprising control means of the second phase connected to the second chamber to ensure the existence of a single liquid phase in the second chamber . 44. A reactor device as defined in claim 38, 39, 40, 41, or 42, further comprising catalyst precipitation control means connected to the second chamber to ensure the absence of precipitated catalyst in the second chamber. 45. A reactor device as defined in claim 38, 39, 40, 41, 42, 43, or 44, wherein at least two of the chambers constitute one of the same unit. 46. A reactor device as defined in claim 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, or 45, comprising an atomization chamber. 47. A reactor device as defined in claim 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, or 45, comprising a stirred tank reactor. RESU MEN Methods and devices are described to control the reaction of a hydrocarbon to an acid by making adjustments related to the phase. In order to improve the oxidation reaction and reactivity regime, a single phase is obtained at the operating temperature and it is maintained by adjusting one or more of the gaseous oxidant flow rate, pressure in the reaction zone, temperature in the zone Reaction, hydrocarbon feed regime, solvent regime, water supply regime if the water is being fed, catalyst feed rate and other parameters. Methods and devices are also described, wherein a hydrocarbon is reacted in a quiescent state with a gaseous oxidant to form an acid in a liquid mixture. The amount of water is maintained between a maximum water level, above which the maximum level of substantially the single liquid phase is transformed to two liquid phases and a minimum level below which the catalyst precipitates. In addition, methods are described, wherein the temperature of the mixture is lowered to a point at which solid dibasic acid precipitates, while maintaining a single liquid phase and optionally all of the catalyst in solution. At least part of the acid formed is then removed. The preferred hydrocarbon is cyclohexane, the preferred acid is adipic acid, the preferred solvent is acetic acid and the preferred catalyst is cobalt acetate tetrahydrate (I I).