MXPA99005998A - A method for the production of polyadducts of alkylene oxides with a liquid in gas dispersion reactor - Google Patents

Abstract

The present invention relates to a semi-continuous method for the production of polyadducts of alkylene oxide by an addition reaction of alkylene oxide on a chain initiator having at least one active hydrogen. In the method of the present invention, there is provided a reactor (1) constituted by a cylindrical body with two diameters, the upper part being of larger diameter than the lower part, heat-exchange means (2) and recycling ducts (13, 15) for the recycling of the reaction mixture from the bottom to the head of the reactor in order to obtain the final desired product. The process of the present invention enables the production to be carried out with greater flexibility and reduces down times;with the use of the aforesaid reactor it is in fact possible to start the process with a volume of chain initiator of up to 1/90 of the volume of the final reaction product, allowing very high molecular weights to be reached in a single production batch or, if necessary, smaller quantities of polyadduct for the same growth.

Description

METHOD FOR THE PRODUCTION OF POLYADUCTS OF OXIDES OF RENTING WITH A LIQUID DISPERSION REACTOR IN GAS Description of the invention The present invention is concerned with a new semicontinuous process and apparatus for the production of alkylene oxide polyadducts by an addition reaction of alkylene oxide on a chain initiator having at least one active hydrogen. These products, particularly the ethylene oxide and propylene oxide polyadducts, are mainly used as nonionic surfactants and polyether polyols. Nonionic surfactants are very widely used as wetting agents, dispersants, stabilizers, emulsifying and anti-emulsifying agents, antifoaming and foaming agents and in general as auxiliary chemical compounds and functional fluids in the textile, paper, cellulose, pharmaceutical and food industries. , cosmetics, paints, resins, mineral extraction and processing, advanced recovery and oil extraction. In particular, mention should be made of the use of nonionic surfactants based on natural or synthetic fatty alcohols as primary components in the formulation of household and industrial detergents and also of polyether-polyols as the main intermediates in the production of polyurethanes.

REF .: 30630 (rigid, semi-rigid, flexible foams, elastomers, adhesives, sealants, etc.). Italian patent No. 1 226 405 describes a method for the production of polymerization products of alkylene oxides from alkylene oxides, ethylene and / or propylene oxides are the most commonly used and compounds having a hydrogen atom active or mobile with appropriate catalysts. The method of this patent uses a two-section reactor of which the upper section is called the gas-liquid reactor and the lower one is an accumulation tank, arranged essentially horizontally. The liquid gas reaction is carried out in the upper section, the chain initiator is fed with a plurality of spray or spray heads in a central distributor while the lower body acts as a container or reservoir and for recycling by means of of a pump and an external heat exchanger, the reaction product from the upper section is fed back to the last to control the polymerization reaction. Italian patent No. 1 226 406 discloses a method for obtaining alkylene oxide polymerization products using a two-section reactor of which the upper section is referred to as the liquid-gas reactor and the lower one as a reservoir or accumulation vessel. , each section has a plurality of spray or spray nozzles. The first phase of the reaction occurs in the lower section which is arranged vertically and continues until a given amount of the polymerization product is formed; Subsequently, the polymerization reaction is transferred to the horizontally arranged upper section, where the reaction can continue until the desired product is obtained. The processes described in the patents mentioned above, however, have several disadvantages. First, they use two-section reactors that complicate the overall structure of the plant and increase costs; the two-section reactors also have a large diameter communication aperture and for Italian patent 1 226 406, a larger number of apertures, to increase the possibility of loss of alkylene oxides and the formation of dead zones and exposed internal surfaces to the oxide. Since internal distributors of two sections are provided, the surface-to-volume ratio of these reactors is greater, which increases the likelihood of secondary reactions. The double body configuration and the presence of internal distributors also creates dead spacing inside the reactor that makes it difficult to drain and clean the reactor, to increase the problems in the change of production. It should also be mentioned that the flow under the force of gravity of the reaction product that accumulates in the upper horizontal section and then is conducted downward to the lower one induces backscattering and hence overexposure to the oxidizing atmosphere. The problem at the root of the invention is thus to provide a process for the production of alkylene oxide polyadducts which is capable of overcoming the problems of the prior art. The problem is solved according to the invention by means of a semi-continuous process for the production of alkylene oxide polyadducts, by the addition reaction of alkylene oxide on a chain initiator having at least one active hydrogen, characterized in that it includes the steps of: providing a reactor constituted by a cylindrical body with two diameters, arranged with its longitudinal axis substantially vertical, with the upper part of the cylindrical body of a larger diameter than the lower part and the reactor having openings or inlet and outlet orifices, equipment to atomize the reaction mixture and equipment to atomize the alkylene oxide, the atomization equipment is located and arranged on the entire inner surface of the upper part of the reactor; - charging the reactor with a predetermined volume of liquid including the chain initiator; - discharging the liquid through the outlet opening and bringing it to a predetermined reaction temperature by means of heat exchange elements; - atomizing the liquid by means of the atomization equipment and introducing the alkylene oxide through the atomization equipment to obtain an intermediate liquid reaction product that forms a mixture with the liquid chain initiator; recycling the obtained mixture continuously after it has been brought back to the predetermined reaction temperature by atomizing it in the upper part of the reactor by means of the atomization equipment and making it react with an additional amount of alkylene oxide in order to obtain an final product with the desired chain length. The chain starter is usually used in amounts equal to the ratio between the final amount of the product and the growth rate where the growth ratio is defined as the ratio between the molecular weight of the product and the molecular weight of the initiator of the product. chain. The chain initiators that can be used are compounds that have at least one active hydrogen according to the final product that it is desired to obtain; examples of such chain initiators can be found among alkylphenols, such as octylphenol, nonylphenol, dodecylphenol, dinonylphenol, tristyrylphenol; natural and synthetic fatty alcohols and mixtures thereof, such as decyl alcohol, tridecyl alcohol, oleyl alcohol, oleylacetic alcohol, cetylstearyl alcohol, lanolin, cholesterol, acetylene diol; fatty amines and hydrogenated amines, such as lauryl amine, oleyl amine, amine derived from coconut oil, bait amine and soy amine, soy iminopropylenamine, abiethylamine; fatty amides, such as lauryl amide, stearyl amide, fatty amides derived from coconut oil, soybean and bait; fatty acids such as coconut, lauric, bait, stearic, palmitic, oleic, myristic, linoleic, abietic and naphthenic acids, sorbitan esters such as monolaurate, monopalmitate, monostearate, monooleate, monoabietate, dilaurate, tristearate, trioleate, pentalaurate , hexaoleate, hexatestearate; monoglycerides and monostearates of for example, coconut and glycerol; penteritritol esters, such as monolaurate, mono oleate and lanolin; ethylene glycols, such as mono-, di-, triethylene glycols and polyethylene glycols; propylene glycols, such as mono-, di-, tripropylene glycols and polypropylene glycols; block polymers of ethylene oxide / propylene oxide and random or disordered sequences thereof based on various chain initiators, such as fatty amines, fatty alcohols, glycerol, dipropylene glycol; oils such as castor oil, hydrogenated castor oil, mink oil, bait oil and pine; mercaptans such as dodecyl mercaptan. In order to activate the alkoxylation reaction, to accelerate it and whenever necessary a catalyst is introduced to the reactor which must be completely dispersed in the chain starter to give rise to the reaction of the alcoholate in situ. A particularly preferred embodiment of the invention provides the use of a basic catalyst which is selected from the group comprising alkali metal hydroxides and alcoholates and * alkaline earth metal hydroxides. However, acidic catalysts can also be used, although they are not preferred since they have the disadvantage of increasing the concentration of dioxane in the product. The catalyst can be added either in the solid phase or in aqueous solution and is introduced directly into the external recycling conduit, where it is mixed with the chain initiator which is already upstream of the reactor. When desired, however, it is possible to introduce the catalyst directly into the reactor body and mix it with the chain initiator therein. Before the reaction is initiated, it is necessary to atomize the catalyzed reaction initiator to form finely dispersed droplets in the reactor atmosphere. In order to form this liquid phase, the mixture is recycled through an external circuit from the lower part to the upper part of the reactor, where a plurality of atomizers are installed, these are distributed on the internal surface of the upper part. The chain initiator is dispersed over a complete cone that can vary from 15 ° to 150 ° and is effected with atomizing devices that generate droplets having a Sauter diameter of less than 500 μm. To take advantage, each atomizer comprises a hollow body substantially conical in trunk projecting into the wall of the reactor at the larger diameter end in which the atomizer is in fluid communication with the external recycling circuit. A plurality of nozzles are provided in the atomizer body evenly distributed over the surface thereof, by means of which the atomized liquid phase is introduced into the reactor. It is appropriate to emphasize that the cone-shaped shape of the atomizer allows the nozzles to be oriented inside the reactor to feed the atomized liquid over a cone at a very large angle. It is particularly advantageous to bring the chain initiator to the temperature at which the polyaddition reaction occurs before the alkylene oxide is added in order to minimize the time at which the reaction itself is induced. For this purpose, a preferred embodiment of the present invention provides a heat exchanger in the external circuit for heating the catalyzed chain initiator during its recycling. A particular embodiment of the present invention also provides that the lower part of the reactor and the external recycling circuit are maintained at a predetermined temperature to prevent solidification of the chain starters with high melting points during charging and subsequent heating of the initiator of chain. A preferred embodiment of the present invention provides a step in which the catalyzed chain initiator is dried before the reaction is initiated. The drying is carried out inside the reactor by means of a combination of evacuation and heat. With the use of the process of the present invention, by virtue of the very high degree of dispersion of the catalyzed chain initiator in the gas phase in the reactor and the large number of recycling circuits per unit of time it is possible to reduce the humidity present in the reactor to less than 50 ppm. This drastically reduces the amount of polyethylene glycols or polypropylene glycols that are formed at the same time as the desired product. The alkoxylation reaction is usually carried out at temperatures that can vary between 70 ° C and 195 ° C, preferably between 90 ° C and 180 ° C according to the type of production and at a relative pressure partially determined by the presence of inert gas, in general nitrogen and partly by the alkylene oxide itself. In general, the relative pressure of the reaction is not greater in a case of 6 x 102 KPa. Then, the liquid alkylene oxide is introduced into the reactor where it is contacted with an atmosphere of inert gas and finely dispersed droplets of catalyzed chain initiator. Immediately, the oxide comes into contact with the chain initiator, vaporizes it and begins to dissolve in the drops. As mentioned above, the high dispersion of the liquid phase in the gas allows the exchange of mass and energy between the two phases to occur immediately with a reagent contact time equal to the time of flight of the drops. The process according to the invention is particularly effective when alkylene oxides selected from the group comprising ethylene oxide, propylene oxide, methylene oxide and mixtures thereof are used. As the reaction proceeds and the molecular weight increases, the lower part of the reactor is filled with the reaction product, while the heat of reaction is removed by the heat exchange elements. In a particularly advantageous embodiment, the heat exchanger is located in the external recycling circuit and is the same as that used in the pre-reaction step to heat the liquid containing the catalyzed chain initiator. This mode, with the heat exchanger located in the external recycling circuit, allows an extremely good transfer of the heat evolved by the exothermic reaction to be obtained. During the reaction, the alkylene oxide is added with the automatic control of the mass, pressure and reaction temperature transmitted directly from the reactor and the reaction circuit and the temperature of the pressurized cooling water.

The alkylene oxide is absorbed quantitatively in the upper part of the reactor in which the catalyzed initiator drops are finely dispersed in the gaseous atmosphere constituted by inert gas and alkylene oxide. As the alkoxylation reaction is carried out in the liquid phase, there is a progressive reduction in the consideration of alkylene oxide in the liquid mass in the reactor, the oxide moves from the free surface of the reactor to the bottom thereof. . Corresponding to the reduction in the concentration of the alkylene oxide, the temperature increases from the free surface to the bottom of the reactor, as the exothermic alkoxylation reaction is. The reaction mechanism, being free of backscattering, is gradually combined to lower the dissolved alkylene oxide concentrations with gradually increasing temperatures in the reaction mass. Hence, for a given reaction kinetics, the concentration of alkylene oxide in the reaction product leaving the bottom of the reactor to be recycled is lower than that obtainable by other processes, in particular in conventional stirred reactors and reactors with systems Internal venturi with a bubble diffusion mechanism for alkylene oxide. An additional result is that the quality of the product, which is linked to the side reactions of the alkylene oxide, is improved. After the reaction phase, the alkylene residue is expelled and the product obtained has a free alkylene oxide content of at least 1 ppm. In some cases and only if strictly necessary, the final product is distilled before being cooled and neutralized. In any case, all the post-reaction stages can be carried out in the same reactor as that used for the process which is the subject of the present invention. A particular form of the present invention provides the addition of at least one conventional reactor and / or reactor of the type used in the process of the present invention in series or in parallel. The series arrangement allows the production of poly-products with high growth, in very short production times, while the parallel arrangement allows a considerable increase in the flexibility of the production of the plant. This modality also allows the process to be initiated with initiators of. solid chain (to be melted), solids in suspension, in aqueous solution or in solvents or the production of polyadducts with high viscosities (of more than 700 cP):. The process of the present invention also allows the use of chain initiators that are liquid, solid (before melting), in suspension, in aqueous solution, in solvents, etc .; it is thus possible to operate chain starters with a high range of viscosities, densities, vapor pressures, molecular weights, acidities, unsaturation, etc. The process for the production of alkylene oxide polyadducts according to the present invention also allows high productivities to be obtained, since, by virtue of the very high dispersion, the transfer of gas-liquid material is considerably improved, to give better alkylene oxide absorption for a given amount of chain initiator, type and concentration of the catalyst, partial pressure of alkylene oxide and reaction temperature and also shorter drying times for a given residual moisture content. The process of the present invention also provides greater production flexibility and shorter shutdown times; With the configuration described above, it is indeed possible to start the process with a volume of chain starter up to 1/90 of the volume of the final reaction product, to allow very high levels to be obtained in a single production lot or if it is necessary, the production of quantities of poly-product for the same growth. The high transfer of material allows more favorable reaction conditions to be obtained and also more de-aeration and complete dehydration of the chain initiator which results in less formation of by-products and undesirable contaminants. The product obtained is thus of better and more consistent quality. The shape of the reactor and the absence of distributors therein offer a smaller surface-volume composition and a very long gas-liquid contact time in the upper part of the reactor. This minimizes the proportion of the surface area (S) of the metal exposed to the gaseous alkylene oxide to the free volume (V) of the vaporized oxide itself., this proportion is not higher for example of 1.55 m "1 for reactors that have a capacity of 10 tons / batch and of 1.30" 1 for reactor that have a capacity of 50 tons / batch and creates a very high concentration gradient of the oxide of alkylene from the top to the bottom of the reactor, with a very high temperature gradient from the bottom to the top. The almost total lack of residual oxide in the reactor, particularly in the area in which the temperature is higher, provides greater safety, particularly with respect to the danger of explosions, than conventional reactors having a bubble dispersion model for the oxide. The lack of dead spaces also means that the residual product in the reactor and in the associated circuit when the final product is discharged is less than 0.05 kg / m2 of internal surface of the reactor. With the process of the present invention it is thus possible to carry out numerous production cycles or certainly to change the type of production, without the quality of the final product of a lot being affected by the presence of a considerable amount of the residual material from the previous batch. . The distribution of the atomizers on the internal surface of the upper part of the reactor allows 100% of the internal volume of the reactor to be covered whatever the level of the reaction liquid, to maximize the transfer of the material for any degree of growth and minimize the coalescence of the drops on the wall before they reach the free surface of the liquid phase. Since the internal surface of the upper part of the reactor is completely wetted by the reaction liquid, the formation of any hot spots is prevented, due to the heat fluxes located from the outside of the reactor, in order to considerably reduce the probability of explosions in the reactor. the reactor itself. The process according to the invention allows growths of up to ninety times the weight of chain starter and more in a single reaction step without the need for post-reaction and / or intermediate ventilation steps and / or as in the conventional alkoxylation processes, discharges to a deposit or containers of intermediate products. A further advantage of the present invention, particularly for ethoxylation, lies in the total absence of mechanical seals in contact with alkylene oxide vapors which considerably reduce the probability of exceeding the minimum energy threshold for activation of the oxide vapor. of ethylene. The process according to the present invention also reduces the concentration of dioxane in the final product surprisingly compared to the prior art, which result is thus more ecological and less hazardous to health. In addition, the type of reactor used in the process of the present invention can be washed (if necessary) more easily and quickly by virtue of its composition of its surface - smaller volume, absence of dead spaces (absence of internal distributors and other internal parts) and the smallest amount of residual material at the end of the reaction. The distribution of the atomizers on the inner surface of the upper part of the reactor also allows the entire inner surface of the reactor to be washed more efficiently, with smaller amounts of water or solvent. The wash liquid discharged consequently also contains less harmful substance and is thus less difficult to regenerate. The process of the invention, by virtue of the structural characteristics of the type of reactor used and all the concurrent aspects mentioned above, for example, the lower amount of toxic emissions at the end of the reaction and the lower energy consumption due to the high efficiency of the various reaction cycles, thus having less environmental impact than the processes of the prior art. In an additional aspect, the present invention provides a reactor for the proportion of alkylene oxide polyadducts by an addition reaction of alkylene oxide on a chain initiator having at least one active hydrogen, characterized in that it comprises a cylindrical body with two diameters arranged with its longitudinal axis disposed substantially vertically, with the upper part of the cylindrical body being of greater diameter than the lower part and the reactor is provided with openings and inlet and outlet holes, equipment for atomizing the reaction mixture and the oxide of alkylene, the atomization equipment is located and distributed on the internal surface of the upper part of the cylindrical body. The features and advantages of the invention will become more apparent from the description that follows of the embodiments of the process described above, made with reference to the apparatus shown schematically in the single annexed drawing, given only by way of example. With reference to the drawing, the apparatus used for the process of the invention comprises a reactor 1, constituted by a cylindrical body with two diameters arranged with its vertical longitudinal axis, a heat exchanger 2 and a centrifugal pump 3 for recycling the reaction product through a discharge duct 13, the heat exchanger 2 and a recycling duct 15 from a lower part 4 of the reactor 1 to an upper part 5 of the greater diameter than the lower part 4. The lower part 4 has a device with means tubes and / or special plates 6 provided or fed continuously with steam or pressurized hot water. An inlet conduit 7 is provided in the reaction circuit for feeding a chain initiator to reactor 1. The latter includes four inlets 8, of which only three are visible in the drawing, each associated with an atomizer 9 for atomizing the recycled product fed to top 5 of reactor 1, four openings or holes 10, of which only two are visible in the drawing, each associated with an atomizer 11 for atomizing the alkylene oxide fed into the top 5 of the reactor 1 and an outlet opening 12 for the recycling of an intermediate reaction product by means of ducts 13, 15. Each of the atomizers 9 and 11 comprises a hollow body of conical trunk on which a plurality of small nozzles are formed. , in the example eight nozzles, which project from the body itself and are uniformly disposed thereon. The atomizers 9 are distributed on the surface of the upper part 5 of the reactor 1. One of them is located at the apex of the reactor 1 while the other three are contained in a plane perpendicular to the longitudinal vertical axis and are circumferentially spaced at 120. each. Instead of these, the four atomizers 11 are located symmetrically around the atomizer 9 at the apex of the reactor. Downstream of the recycling pump 3 and upstream of the heat exchanger 2 there is a conduit 16 for the discharge of the final product while downstream of the heat exchanger 2 there is an inlet conduit 17 for the catalyst. The heat exchanger is fed with hot or cold pressurized water through the inlet and outlet ducts 18 and 19; any other conventional fluid, such as a diathermic oil may however be used in place of pressurized water. The reactor 1 is fed with chain initiator, liquid, through the conduit 7 until a predetermined weight is reached. At this point, the fed liquid is recycled via the pump 3 through the exhaust port 12 and the heat exchanger 2 and is reintroduced to the reactor 1 via the conduit 15 and the atomizers 9 in the form of droplets finely scattered. At the same time, the catalyst to be used for the polymerization reaction is introduced into the recycling conduit 15 via conduit 17. The catalyst is completely dispersed in the liquid phase of the chain initiator: a fine dispersion of droplets containing the initiator of chain, catalyst and water is thus obtained at the top of the reactor. The catalyzed chain initiator is thus dried by means of heat and vacuum. Once the optimum conditions for activating the reaction (temperature, catalyst concentration, moisture content, pressure, etc.) have been reached, the alkylene oxide supply is started through the conduit 14, the openings 10 and the atomizers 11. This initiates the absorption of the oxide by the drops of the catalyzed chain initiator in the upper part of the reactor 1 and hence the chemical reaction in the lower part of the reactor 1. Indeed, the droplets saturated with alkylene oxide coalesce on the free surface of the liquid phase in reactor 1 where the alkoxylation reaction is carried out. The liquid phase, after an appropriate residence time, is recycled through the duct 15 and continuously emitted to the upper part of the reactor 1 through the atomizers 9. During recycling, the liquid phase continuously provides its heat, the most of which is released by the strongly exothermic alkoxylation reaction, in the heat exchanger 2 to which, meanwhile, pressurized cooling water is fed. Then, the reaction proceeds with the alkylene oxide which is fed continuously until the desired molecular growth is obtained. The product is cooled and if necessary, distilled and neutralized and finally discharged from the reactor and associated circuit through conduit 16 before an additional production cycle is initiated.

EXAMPLE 1 Production of 10,000 Kg of fatty alcohol of 12 to 14 carbon atoms + 2.8 moles of ethylene oxide. The reactor of the plant described above, having an S / V ratio of 1.55 m -1, is charged with 6125 Kg of fatty alcohol of 12 to 14 carbon atoms (MW 195) and 2.5 Kg of NaOH as the catalyst. This is dried at a temperature of 135 ° C with a vacuum of 5 mbar and after the vacuum has been replaced by nitrogen and the mixture has been heated to the reaction temperature (160 ° C), 3875 Kg of oxide is reacted of ethylene at a maximum relative reaction pressure of 4.75 x 102 KPa. At the end of the reaction, the product is cooled, neutralized and discharged. No distillation or post-treatments are carried out. The total production time is 170 minutes from the loading of the first material to the discharge of the finished product. The quality of the product is as follows: Appearance at 25 ° C Clean Color, APEA 5 max Water (ppm) 100 max pH (3% aqueous solution, 25 ° C) 6 - 7 Hydroxyl number (mg KOH / g) 176 +/- 1.5 Polyethylene glycol (% by weight) 0.25 max Ash (AA) (ppm) 200 max Dioxane (ppm) 1 max Free ethylene oxide (ppm) 0.5 max EXAMPLE 2 Preparation of 10,000 Kg of nonylphenol + 9.0 moles of ethylene oxide The reactor of the plant described above, having an S / V ratio of 1.55 m_1, is charged with 3569 Kg of nonylphenol (molecular weight 220) and 2.5 Kg. of NaOH as a catalyst. The drying is carried out at a temperature of 140 ° C with a vacuum of less than 5 mbar and after the vacuum has been replaced by nitrogen and the mixture has been heated to the reaction temperature (165 ° C), 6431 Kg of ethylene oxide are reacted at a maximum relative reaction pressure of 4.75 x 102 KPa When the reaction is finished, the mixture is cooled, neutralized and discharged, no distillation or post-treatment is carried out. The total production time was 185 minutes from the loading of the first material to the discharge of the finished product.The quality of the product was as follows: Appearance at 25 ° C Clean liquid Color, APHA 10 max Water (ppm) 100 max pH ( 3% aqueous solution, 25 ° C) 6.5 +/- 0.5 Hydroxyl number (mg KOH / g) 91 +/- 1 Polyethylene glycol (% by weight) 0.25 max Ash (AA) (ppm) 200 max Dioxane (ppm ) 2 max Free ethylene oxide (ppm) 0.5 max It is noted that, in relation to this date, the best method or known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (18)

1. Claims Having described the invention as above, the content of the following claims is claimed as property: 1. A semi-continuous process for the production of alkylene oxide polyadducts, by the addition reaction of alkylene oxide on a chain initiator having at least one active hydrogen, characterized in that it includes the steps of: - providing a reactor constituted by a cylindrical body with two diameters, arranged with their longitudinal axis substantially vertical, the upper part of the cylindrical body of a greater diameter than the lower part and the reactor has inlet and outlet openings, equipment for atomizing the reaction mixture and equipment for atomizing the alkylene oxide, the atomization equipment is located and arranged on the entire inner surface of the upper part of the reactor; - charging the reactor with a predetermined volume of liquid including the chain initiator; - discharging the liquid through the outlet opening and bringing it to a predetermined reaction temperature by means of heat exchange elements; - atomizing the liquid by means of the atomization equipment and introducing the alkylene oxide through the atomization equipment to obtain an intermediate liquid reaction product that forms a mixture with the liquid chain initiator; - recycling the obtained mixture continuously after it has been brought back to the predetermined reaction temperature, by atomizing it in the upper part of the reactor by means of the atomization equipment and having it react with an additional amount of alkylene oxide in order to obtain a final product with the desired chain length.
2. 2. A process according to claim 1, characterized in that the step of bringing the liquid that includes the chain initiator to the predetermined reaction temperature is immediately followed by a step in which the liquid is mixed with a catalyst.
3. 3. A process according to claim 3, characterized in that the chain initiator and the catalyst are subjected to a drying step before the step in which the alkylene oxide is introduced into the reactor.
4. 4. A process according to claim 2 or claim 3, characterized in that the means are constituted by a heat exchanger.
5. 5. A process according to claim 4, characterized in that the catalyst is introduced downstream of the heat exchanger.
6. 6. A process according to claim 4 or claim 5, characterized in that the recycled intermediate liquid product is brought back to the predetermined temperature by cooling by means of the heat exchanger.
7. A process according to any of the preceding claims, characterized in that the atomization equipment comprises a hollow body, substantially conical trunk projecting inwardly from the reactor wall of a larger diameter end in which the equipment of atomization is in fluid communication with respective conduits, for the recycled stream and for the alkylene oxide, a plurality of nozzles that are formed in the hollow body, which nozzles are evenly distributed over the surface thereof.
8. 8. A process according to any of the preceding claims, characterized in that the alkylene oxides are selected from the group comprising ethylene oxide, propylene oxide, butylene oxide and mixtures thereof.
9. 9. A process according to any of the preceding claims, characterized in that the chain initiator is selected from the group comprising alkylphenols, natural and synthetic fatty alcohols and their mixtures, fatty amines and hydrogenated amines, fatty amides, fatty acids, esters of sorbitan, monoglycerides and monostearate, esters of pentaerythritol, ethylene glycols, propylene glycols, block polymers made from ethylene oxide / propylene oxide and polymers obtained from random or disordered sequences of the latter based on several chain initiators, such as, for example, amines fats, fatty alcohols, glycerin, dipropylene glycol, etc., castor oil, hydrogenated castor oil, bait, mink oil, pine oil and mercaptans.
10. 10. A process according to any of the preceding claims, characterized in that the catalyst is selected from the group comprising alkali metal hydroxides and alcoholates and alkaline earth metal hydroxides.
11. 11. A process according to any of the preceding claims, characterized in that the reaction temperature is between 70 ° C and 195 ° C.
12. 12. A process according to any of the preceding claims, characterized in that there is a relative pressure of not more than 6. 102 KPa in the reactor.
13. 13. A process according to any of the preceding claims, characterized in that at least one conventional reactor and / or one reactor according to the preceding claims is added in series or in parallel with the reactor.
14. 14. A reactor used for the process according to claims 1 to 13, characterized in that it comprises a cylindrical body with two diameters, arranged with its longitudinal axis substantially vertical, with the upper part of the cylindrical body of greater diameter than the lower part and the reactor has inlet and outlet openings, equipment for atomizing the reaction mixture and equipment for atomizing the alkylene oxide, the atomization equipment is located and arranged on the entire internal surface of the upper part of the cylindrical body.
15. 15. A reactor according to claim 14, characterized in that the atomizing equipment comprises a substantially conical, hollow body trunk projecting inward from the reactor wall from a larger diameter end in which the atomizing equipment it is in fluid communication with respective conduits for the recycle flow and for the alkylene oxide feed, a plurality of nozzles are formed in the hollow body and are homogeneously distributed on the surface thereof.
16. 16. A process according to claim 1, characterized in that the chain initiator is dispersed on a complete cone that varies from 15 ° to 150 ° with droplets having a Sauter diameter of less than 500 μm.
17. 17. A reactor according to claim 14 or 15, characterized in that it has a capacity of 50 tons / lot, in which the proportion of the surface area of the metal exposed to the gaseous alkylene oxide to the free volume is equal to or less than 1.30 m_1 .
18. 18. A reactor according to claim 14 or 15, characterized in that it has a capacity of 10 tons / lot, in which the proportion of the surface area of the metal exposed to the gaseous alkylene oxide to the free volume is equal to or less than 1.55 m "1.