MXPA01008493A - Methods of extracting catalyst in solution in the manufacture of adipic acid. - Google Patents

Abstract

This invention relates to methods of extracting in solution a metal catalyst from a reaction mixture produced by oxidizing cyclohexane to adipic acid in the presence of acetic acid and the metal catalyst. According to this invention, substantially the totality of the cyclohexane is removed, as well as a major part of the adipic acid. A major part of the acetic acid is also removed without precipitating catalyst, thus forming a concentrate in solution. In a preferred embodiment of the instant invention, the concentrate enters a counter-current stream of counter flowing water and cyclohexanone, resulting in an aqueous solution of metal catalyst, which is the extract, and a phase of concentrate solution dissolved in cyclohexanone, which is the raffinate. The two solutions are further treated and/or recycled.

Description

METHODS OF EXTRACTION OF A CATALYST IN SOLUTION IN THE MANUFACTURE OF ADIPIC ACID TECHNICAL FIELD • This invention relates to methods of oxidation of a cyclohexane to adipic acid and more specifically, to the manner of continuously extracting a catalyst as a solution, preferably for recycling. 10 BACKGROUND TECHNIQUE fl There are a large number of references (both in patents and in articles of literature) related to the formation of acids, with adipic acid being one of the most important, through the oxidation of hydrocarbons. The adipic acid is used to produce fibers and resins of Nylon 66, polyesters, polyurethanes, and various other compounds. There are different processes in the manufacture of adipic acid. The conventional process involves a first step of • Oxidation of cyclohexane with oxygen to a mixture of cyclohexane and cyclohexanol (KA mixture), and then oxidation of the KA mixture with nitric acid to adipic acid. Other processes include, among others, the "Hydroperoxide Process", the "Boric Acid Process", and the "Direct Synthesis Process", which comprises the direct oxidation of cydohexane to an adipic acid with oxygen in the ^^ ftiriaif ^ --'- - * - "--- - • --- ... ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ , IH-JG ti üMTny presence of solvents, catalysts, and promoters, attention has been given for a long time to the Direct Synthesis Process, however, small commercial successes have been found to date, one of the reasons is that • 5 Although it looks very simple at first glance, it is actually extremely complex. Due to this complexity, you can find results, comments, and extremely conflicting views in different references. It is well known that after it takes place In a reaction according to the Direct Synthesis, a mixture of two liquid phases is presented at room temperature, together with a solid phase consisting mainly of adipic acid. The two liquid phases are called "Polar Phase" and "Non Polar Phase". However, until now it has not been 15 note the importance of the two phases, except to separate the adipic from the "Polar Phase" and recycle these phases in the reactor partially or totally with or without additional treatment. • It is also important to note that most of the Direct Synthesis studies have been conducted in a batch mode, literally or for all practical purposes. As mentioned above, there are a lot of references related to the oxidation of 25 organic compounds to produce acids, such as, for example, adipic acid and / or intermediates, such as for example cyclohexanone, cyclohexanol, cyclohexylhydroperoxide, etc. The following references, among others, can be • 5 to be considered as representative of the oxidation processes related to the preparation of diacids and other intermediate oxidation products. U.S. Patent Number 5,463,119 (Kollar); United States Patent of 10 North America Number 5,374,767 (Drinkard et al.); • Patent of the United States of America Number 5,321,157 (Kollar); Patent of the United States of North America Number 3,987,100 (Barnette et al.); Patent of the United States of America Number 15 3,957,876 (Rapoport et al.); Patent of the United States of North America Number 3,932,513; Patent of the United States of North America Number 3,530,185 (Pugi); Patent of the United States of America Number • 3,515,751 (Oberster et al.); Patent of the States 20 United States of America Number 3,361,806 (Lidov et al.); U.S. Patent Number 3,234,271 (Barker et al.); U.S. Patent No. 3,231,608 (Kollar); Patent of the United States of America Number 25 3,161,603 (Leyshon et al.); Patent of the States Í3É¿jtjJ 'Wlf' "T t T '' - • * '"' "'" - "*" "-" - * - »- • - -". * M * r * m ** ** ** ************* * * -. **. * United States of America Number 2,565,087 (Porter et al.); Patent of the United States of America Number 2,557,282 (Hamblet et al.); Patent of the United States of America Number 2,439,513 (Hamblet and • 5 collaborators); Patent of the United States of America Number 2,223,494 (Loder et al.); Patent of the United States of America Number 2,223,493 (Loder et al.). German Patent Number DE 44 26 132 Al (Kysela et al. 10) discloses a dehydration method of the process acetic acid ifl from the liquid phase oxidation of cyclohexane with air, in the presence of cobalt salts as a catalyst after separation of the adipic acid after filtration, while simultaneously preventing the cobalt salt from precipitating in the dehydration column, characterized in that the phase of the acetic acid to be returned to the beginning of the process is subjected to azeotropic distillation by the addition of cyclohexane, under the distillation removal of water 20 down to a residual content of less than [sic] 0.3 percent to 0.7 percent. International Publication of TCP Number WO 96/03365 (Costantini et al.) And United States Patent Number 5,756,837 (Costantini et 25 collaborators) disclose a process for recycling a ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡^ ^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ rmfc rf? -1- ^ - t- "-> - - - catalyst containing cobalt in a direct oxidation reaction of cyclohexane to an adipic acid, characterized in that it includes a step in which the reaction mixture obtained by oxidation to adipic acid 5 it is treated by extraction of at least a portion of glutaric acid and succinic acid formed during the reaction None of the above references, or any other reference known to the inventors, discloses, 10 suggests or implies, singularly or in combination, the control of oxidation reactions subject to the intricate and critical controls and requirements of the present invention as described and claimed.

DISCLOSURE OF THE INVENTION As mentioned above, this invention relates to oxidation methods of hydrocarbons, such as cyclohexane for example, up to the oxidation products • respective intermediates, such as adipic acid for For example, and more specifically, how to continuously extract a catalyst in solution, preferably for recycling. More particularly, this invention pertains to a method for extracting in solution a metal catalyst from a reaction mixture produced by the oxidation of a cyclohexane. 25 to adipic acid in the presence of acetic acid and the metal catalyst, the method comprising the steps of: (a) substantially removing all of the cyclohexane; (b) remove a greater part of the adipic acid; • 5 (c) remove a greater part of the acetic acid (up to substantially 100 percent), but being careful not to exceed a point of acetic acid removal beyond which the catalyst can begin to precipitate, thus forming a concentrated in 10 solution; flk, (d) introducing the concentrate into the middle region of a countercurrent flow, the countercurrent flow also having a lower region and an upper region, the lower region having a bottom, and having the region 15 upper one top; (e) introducing cyclohexanone, which may comprise a smaller amount of water, into the lower region of the countercurrent flow; • (f) introducing water, which may comprise a minor amount of cyclohexanone, into the upper region of the countercurrent flow; (g) removing a first liquid or raffinate from the top of the upper region, the first liquid comprising most of the concentrate, excluding the catalyst; Y 25 (h) withdraw a second liquid or extract from the *? mm¡ta ¡ulm. rinnnr • '-'-' - - • "" - "- - - - ••» - * *. bottom of the lower region, the second liquid comprising most of the metal catalyst. The metal catalyst is preferably a compound comprising cobalt. The metal catalyst is substantially metal itself, preferably in ionic form, regardless of the compound or fraction with which it is associated. Thus, the metal can be associated with a fraction in step (a) and with a different fraction in step (h); for example, it can be predominantly an acetate 10 of cobalt in step (a), and may be predominantly a cobalt adipate flft, or a cobalt glutarate or cobalt succinate, or any mixture thereof, etc. in step (h). The removal of cyclohexane can be conducted 15 before, during, or after the removal of the adipic acid, or both before and after the removal of the adipic acid. Sooner or later it means at an earlier or later stage of the process, while during it means in the • same stage. For example, cyclohexane can be removed 20 reducing the temperature and allowing the formation of two distinct liquid phases, a non-polar phase containing most of the cyclohexane and a polar phase containing most of the acetic acid, adipic acid and other polar fractions, followed by decanting to remove 25 the non-polar phase, and the crystallization to remove the acid Another alternative is the removal of cyclohexane during crystallization by evaporation of the adipic acid.Cyclohexane can also be removed by distillation. ), (e), 5 (f), (g) and (h) are developed simultaneously In addition, step (c) is preferably conducted by distillation, small amounts of water can be added continuously or intermittently in the It is also highly preferable that substantially all of the acetic acid be removed in step m (c), and that substantially all of the metal catalyst be removed in step (h). the substantially complete removal of the catalyst is required, it is absolutely critical to maintain a sufficiently high temperature in the countercurrent flow portions, such as the upper part of the countercurrent flow, where only small amounts are present. is the catalyst, with the aim of reducing or eliminating the tendency to emulsion. The temperature in the upper, middle, and lower parts can be substantially the same; preferably in a range of 50 ° C to 80 ° C. It is more preferable, however, that the temperature of the upper part be greater than the temperature of the part 25 medium, and that the temperature of the middle part is greater than mm? UuUm Um ^^^ mmmm the temperature of the bottom. Even more preferably, the temperature of the upper part is in a range of 50 ° C to 90 ° C, the temperature of the middle part is in a range of 30 ° C to 50 ° C, and the temperature of the lower part is in a • 5 range from 10 ° C to 40 ° C. This invention also pertains to a solution extraction method of a metal catalyst from a reaction mixture that is produced by the oxidation of a cyclohexane to an adipic acid in the presence of acetic acid and the metal catalyst, comprising the fl) method the steps of: (k) removing substantially all of the cyclohexane; (1) remove most of the adipic acid; 15 (m) remove most of the acetic acid, without precipitating the catalyst, thereby forming a concentrate in solution; (n) introduce the concentrate in an average stage • of a countercurrent multi-stage assembly, 20 the middle stage comprising a medium mixing zone and a medium separation zone, the multi-stage countercurrent assembly also comprising a front stage and a rear stage, the front stage comprising one zone of front mix and a front separation zone, and 25 comprising the rear stage a rear mixing zone and nl ^ y ^! ^ umtt ltt, ,, MMI I r- **** --- ..-- *. * ...., .. ,, ............ -aj ^ ... *****, t- "..- ¿« -f- a rear separation zone; (p) introducing cyclohexanone, which may comprise a minor amount of water, within the frontal mixing zone; • 5 (q) introducing water, which may comprise a minor amount of cyclohexanone within the rear mixing zone; (r) extracting a raffinate from the rear separation zone, the raffinate comprising a larger part 10 of the concentrate, excluding the catalyst; and fl (s) extracting an extract from the back separation zone, the extract comprising a larger part of the metal catalyst. It is preferable that step (m) is conducted by distillation, in which case, the method may further comprise a step of adding water in step (m). At least in the rear separation zone, the separation can be conducted at least partially by • one centrifugation step. In one embodiment of the invention, the rear stage has a temperature of the rear stage, the middle stage has a temperature of the middle stage, the front stage has a temperature of the front stage; and the temperature of the back stage, the temperature of the middle stage, and the temperature of the front stage are substantially yjjMy ^ AjÉÉ ^ É ^^ MlM ^^^ iÉtMM ^ IMéÉlMIiÉMl »li« l n llllr? l? I n. II. < 11 (1 T I ?? n.i. ?? me ?? - 1, .---- ,, a ...... .. a. same. Preferably, the substantially equal temperature is in a range of 50 ° C to 80 ° C. In a different mode, the temperature of the rear stage is higher than the temperature of the middle stage, • 5 and the temperature of the middle stage is greater than the temperature of the front stage. Preferably, the temperature of the back stage is in a range of 50 ° C to 90 ° C, the temperature of the middle stage is in a range of 30 ° C to 50 ° C, and the temperature of the front stage is in a 10 range from 10 ° C to 40 ° C. In accordance with this invention, it is preferable that the substantial totality of the acetic acid be removed in step (m). It is also preferable that the substantial totality of the metal catalyst is removed in step (s). As mentioned above, the metal catalyst is preferably a compound comprising cobalt. The metal catalyst is substantially metal itself, preferably in ionic form, wit considering the • compound or the fraction with which it is associated. Thus, the Metal can be associated with a fraction in step (k) and with a different fraction in step (s); for example, it may be predominantly a cobalt acetate in step (k), and may be predominantly a cobalt adipate, or cobalt glutarate or cobalt succinate, or any 25 mixture thereof, etc., in step (s). g ^ j ^ g ^ l ^^^^^, *. », ..» * M,., .. *, ...,. - "- -" - - * - ** - * - *. *. ... *** "*. *, .. ** ... *. - * - * m It is highly preferable that steps (n), (p), (q), (r) and (s) are carried out simultaneously. In addition, step (m) is preferably conducted by distillation. You can add small amounts of water continuously or from a ^ 5 intermittently in step (m) to maintain the solubility of the metal catalyst. The methods of the present invention may further comprise a reaction step of the produced adipic acid with a reagent selected from a group that 10 consists of a polyol, a polyamine, and a polyamide of a (H) way to form a polyester polymer, or a polyamide, or a polyimide and / or polyamideimide, respectively, which polymer can further be spun into fibers or mixed with fillers and / or other additives to form compounds. "Greater" and "majority" with respect to a fraction, mean more than 50 percent, and up to substantially 100 percent, of said fraction by weight. "Minor" and "Minority" with respect to a fraction, ^ mean less than 50 percent, and up to 0 percent, 20 of said fraction by weight. "Upper phase" means "a relatively less polar phase of cyclohexanone containing the minority of the catalyst", while "lower phase" means "a relatively more polar aqueous phase containing 25 most of the catalyst. "This applies not only in the If the separator is a decanter, which produces a higher cyclohexanone phase and a lower aqueous phase, but also in case the separator is a centrifugal separator, for simplicity purposes . • "Middle stage" is any other stage different from the front stage and the rear stage.

BRIEF DESCRIPTION OF THE DRAWING The understanding of this invention on the part of the reader will be increased by reference to the following detailed description taken in combination with the figure of the drawing, wherein: Figure 1 illustrates a block diagram of a preferred embodiment of the present invention, wherein the extraction of the catalyst is conducted in a countercurrent flow. Figure 2 illustrates a block diagram of another preferred embodiment of the present invention, wherein the extraction of the catalyst is conducted in a multi-stage extraction assembly.

BEST MODE FOR CARRYING OUT THE INVENTION As mentioned above, this invention relates to methods and devices for the oxidation of Cyclohexane to adipic acid for example, and more specifically, how to extract a catalyst in solution after the reaction, preferably to recycle. It has always been a considerable problem the proper handling of the catalyst in the reactions of • 5 oxidation in the technique. In accordance with the present invention, the catalyst is separated into a liquid form dissolved in an aqueous phase, and preferably returned to the reaction chamber with or without any additional treatment. The inventors discovered that the reaction mixture, after the oxidation of cyclohexane to fl omepic acid at a desired degree of conversion, and after removing most of the adipic acid, the remaining cyclohexane together with water and at least most of the acid acetic, can reach or maintain a monophasic liquid state without solids, before and after the addition of the critical amount of cyclohexanone and water. The catalyst can then be extracted with an additional amount of water, or by decreasing the temperature, and ^ preferably return it to the reaction chamber with or without any additional treatment. In accordance with this invention, the catalyst separation process is highly improved by using the techniques described below: Referring to Figure 1, a catalyst separation unit 10 is depicted which «Lanirm -i? ^? ^^^ á? ^ t ^^^^^^^ a ^ ß ^^ i, ^ bMmmmmmm comprises an evaporator or distiller 12, which is connected to the middle region 19 of a complex countercurrent extraction column 14 through a transfer line 16. The complex countercurrent extraction column 14 has • a complex extraction region 18. The column 14 has in addition to the middle region 19, a lower region 20, and an upper region 22. The lower region 20 has a bottom 24 and the upper region 22 has a top 26. A water line 28 and a line of cyclohexanone 30 are connected to the column 10 complex countercurrent extraction 14, which is • in turn connects to the line of the catalyst solution or extraction line 32, and a line of concentrated solution or refining line 34. The evaporator or distiller 12 is connected to the line 15 of steam 15, while an optional additive line 13 and a treated reaction mixture line 11 are connected to the evaporator 12. Part of the evaporator 12 is a heater or heat exchanger 17. mW In Figure 1 no apparatuses are shown in the part 20 front and rear of the catalyst separation unit 10, because these are well described in the majority of our patents and applications, which are incorporated herein by reference. In the operation of this modality, a mixture of The reaction treated from the oxidation of cyclohexane to adipic acid (as described for example in our patents and pending applications, which are incorporated herein by reference) enters the evaporator or distiller 12 through line 11. The reaction mixture 5 is a remnant mixture after removing at least most of the adipic acid from the reaction mixture, where the reaction mixture is produced by the oxidation of the cyclohexane to adipic acid in the presence of acetic acid and a catalyst. of metal, preferably a cobalt compound. The treated flB reaction mixture may contain the majority or the minority of the unreacted cyclohexane. The cyclohexane can be removed by separating the reaction mixture in (i) a polar phase containing most of the acetic acid, adipic acid, other polar fractions, and the catalyst, and (ii) a non-polar phase containing the majority of cyclohexane. In this case, the non-polar phase can be recycled, while most of the adipic acid can be removed by crystallization from the polar phase. The remnant, after removing the adipic acid, constitutes the reaction mixture treated in this case. In a different case, the majority or the minority of the cyclohexane can be removed simultaneously with the crystallization by evaporation of the adipic acid. The remnant, after the removal of the adipic acid, constitutes the reaction mixture treated in this case. -? * i. - .. *. -., ..,., .- .m .- *** - **, *. *. * ***. **. .. * - * .. * ... ... ... .. . . ** * .. *. * XUImUk? T? M It is important to note that removal of the cyclohexane is not necessary, although it is highly desirable, before the treated reaction mixture enters the evaporator or distiller 12. • 5 The treated reaction mixture entering the evaporator 12 it is concentrated to a desired degree by evaporation of the majority of the acetic acid present. It is evident that any cyclohexane present and most of the water evaporates through line 15, even before the acetic acid evaporates, due to its higher volatility. flB It is very important and critical that the concentrate produced by the evaporation of most of the acetic acid comes out through line 16 in the form of a liquid, which even if it is viscous, can still be pumped. During the evaporation process of acetic acid, small amounts of water can be added continuously or intermittently through the line of additive 13. The addition of water can be critical in the decrease • the amount of acetic acid in the concentrate to keep the concentrate in solid-free form, depending on the conversions, the relative levels of the compounds in the concentrate, etc. The concentrate enters the complex extraction region 18 of the complex upstream flow extraction column 14, in which region 18 a flow is present at ÜIÜMTÜMIHIIi rf M ^ dyÜÉiltt countercurrent 18 '. The countercurrent flow 18 'has a middle region 19', which corresponds to the middle region 19 of the column 14. Similarly, the countercurrent flow 18 '• 5 has a lower region 20' (corresponding to the lower region 20 of column 14), and an upper region 22 '(corresponding to upper region 22 of column 14). In addition, the lower region 20 'of the countercurrent flow 18' has a bottom 24 '(corresponding to the bottom 24 of the lower region 20 of the column 14). The upper region 22 'fl of the countercurrent flow 18' has a peak 26 '(corresponding to the top 26 of the upper region 22 of the column 1). As can be seen in Figure 1, the counter-current flow 18 'is produced by a plurality of secondary flows entering and leaving the column 14. One of these secondary flows is the concentrate that enters the middle region 19' of the countercurrent flow • 18 '. Another secondary flow is the flow of cyclohexanone, which is introduced through the cyclohexanone line 30 into the lower region 20 'of the countercurrent flow 18'. Still another secondary flow is the water flow, which is introduced through the water line 28 in the upper region 22 'of the countercurrent flow 18'. 25 Because cyclohexanone has a serious mtif ÉIFUTÉ-El r i TT? G ¡I I -? i? • - ** "-" "-" - - - "" "*. * - ... ** - * .- ***. *.. Tbi * a aa * specific less than water, this is moves upward (in a direction from the lower region 20 'to the upper region 22' of the countercurrent flow 18 ') in the column 14, while the water moves downward (in a direction from the upper region 22') towards the lower region 20 'of the countercurrent flow 18') in the column 14. As the two secondary flows move in opposite directions, the composition of the countercurrent flow 18 'changes from one place to another, giving as Finally, a water phase results, containing at least fl the greater part of the metal catalyst, in the vicinity of the bottom 24 ', and a cyclohexanone phase, which contains at least the greater part of the concentrate, excluding the catalyst, in the closeness of the top 26 '. The water phase, which is the The extract, which contains the majority of the catalyst, is removed by means of the catalyst solution line or extraction line 32, while the cyclohexanone phase is removed by means of the concentrated solution line or the mm refining line. 34. 20 By this technique, the dissolution of the concentrate is achieved with the simultaneous extraction of the metal catalyst in the form of a solution by water. The concentrated or refined solution and the catalyst solution or extract, as discussed in our patents, can also be treated and / or recycled. 25 and previously mentioned patent applications.

The entire metal catalyst can be extracted and removed substantially through the catalyst solution line or extraction line 32 by controlling the temperature and the velocities of the catalyst. • 5 feed through lines 16, 28, and 30. Water entering line 28 may contain a smaller amount of cyclohexanone, while cyclohexanone entering through line 30 may contain a smaller amount of water . Similarly, the 10 solution of the catalyst in water or the extract that comes out • through line 32 it contains a lower amount of cyclohexanone, while the concentrated or refined solution that comes out through line 34 contains a smaller amount of water. In the regions of the countercurrent flow, which have low concentrations of the catalyst, such as for example the upper part 22 'of the countercurrent flow 18', there tends to be an emulsion of water and • Cyclohexanone containing the variety of products, which 20 allows small amounts of the catalyst to be incorporated into the concentrated solution or the refining line 34. In order to substantially reduce or eliminate such a tendency, the temperature of the upper part 22 'has to be above a certain critical temperature, the which can be 25 find easily without undue experimentation. A) Yes, the entire flow can be maintained countercurrent 18 'at a temperature higher than said critical temperature, or at least just at its upper part 22'. An easy way to control the temperatures of the lower part 20 ', the middle part 19' and the upper part 22 'of the countercurrent flow 18' is by controlling the flow temperature of cyclohexanone through line 30, the concentrate flow through line 16, and the water flow through line 28, respectively. In the case that it is desirable to maintain all flow in countercurrent at approximately the same temperature, preferable temperatures are in the range of 50 ° C to 80 ° C. More preferably, however, the temperature of 15 the upper part 22 'is maintained in a range of 50 ° C to 90 ° C, the middle part 19' is maintained in a range of 30 ° C to 50 ° C, and the lower part 20 'remains in a range from 10 ° C to 40 ° C. As mentioned above, an easy way to achieve • this is by controlling the flow temperatures of 20 cyclohexanone through line 30, the flow of the concentrate through line 16, and the flow of water through line 28, respectively, without this being necessary, because heating can be used for this purpose or internal cooling, and / or other means of 25 temperature control.

TEXTILE.MMlW.iÉMÉl MHÜHHkrita rring now to Figure 2, there is shown a catalyst separation unit 110 comprising an evaporator or distiller 112, which is connected to the middle stage 119 of a multiple extraction assembly. • 5 countercurrent stages 114 through a transfer line 116. The middle stage 119 comprises a middle separator 118 and a medium mixer 118a. The multi-stage countercurrent extraction assembly has, in addition to the middle stage 119, a front stage 120, and a 10 back stage 122. Front stage 120 has a front flB spacer 124 and a front mixer 124a. Similarly, the rear stage 122 has a rear spacer 126 and a rear mixer 126a. A water line 128 is connected to the rear mixer 126a, and a line of 15 cyclohexanone 130 to the front mixer 124a. An extraction line 132 is connected to the front separator 124, and a ning line 134 is connected to the rear separator 126. Also shown in FIG.

• Intermediates 136 and 138, which comprise the separators 20 intermediates 140 and 142, respectively, and intermediate mixers 140a and 142a, respectively. However, the number of stages may be greater or less depending on the individual circumstances, and the degree of extraction completed. 25 Mixers and separators are connected between yes through input and output lines as clearly exemplified in Figure 2. Certain input lines are shown to merge with one another to form individual input lines leading to the mixers. • 5 This, however, is not necessary. The input lines can guide the mixers individually and directly. Direct connection is particularly desirable for cases where there is potential for the precipitation of solids. The 10 pumps within the lines are not shown for clarity and brevity purposes to move the different mg / flows from one container to another container, as well as other accessories, but these and their operations are well known in the art. The separators can be decanters, centrifugal separators, or any other type of separator that is suitable for separating two phases in flow from one another. The different stages can be heated or cooled • or parts of the steps (including mixers, 20 spacers, entry and exit lines, etc.) by any means well known in the art. The heating / cooling means for clarity purposes are not shown in Figure 1. The evaporator or distiller 112 is connected to the steam line 115, while a line of additive optional 113 and a treated reaction mixture line 111 are connected to the evaporator 112. The heater or heat exchanger 117 is part of the evaporator 112. The apparatuses at the front and rear of the extraction unit are not shown in Figure 2. of the catalyst 110, because these are well described in many of our patents and applications, which have been incorporated herein by rence. In the operation of this embodiment, a reaction mixture treated from the oxidation of cyclohexane to adipic acid (as described for example in our patents and pending applications, which are incorporated herein by rence) enters the evaporator or distiller 112 through line 111. The treated reaction mixture is a remnant mixture after the removal of at least most of the adipic acid from the reaction mixture., wherein the reaction mixture is produced by the oxidation of cyclohexane to adipic acid in the presence of acetic acid and a metal catalyst, preferably a cobalt compound. The treated reaction mixture may contain the majority or the minority of the unreacted cyclohexane. The cyclohexane can be removed by separating the reaction mixture in (i) a polar phase containing most of the acetic acid, adipic acid, other polar fractions, and the catalyst, and (ii) a non-polar phase that contains most of the cyclohexane. In such a case, the non-polar phase can be recycled, while most of the adipic acid can be removed by crystallization from the polar phase. The remainder, • 5 after removal of the adipic acid, constitutes the reaction mixture treated in this case. In a different case, the majority or the minority of the cyclohexane can be removed simultaneously with the crystallization by evaporation of the adipic acid. The remnant, after the removal of the adipic acid, constitutes the reaction mixture treated in ^ -P such a case. Of course, the cyclohexane can be removed by evaporation, or any other technique. It is important to note that removal of the cyclohexane is not necessary, although it is highly desirable, before the treated reaction mixture enters the evaporator or distiller 112. The treated reaction mixture entering the • Evaporator 112 is concentrated to the desired degree by evaporating the majority of the acetic acid present. It is evident that any cyclohexane present and most of the water evaporates through line 115, even before the acetic acid evaporates, due to its higher volatility. It is very important and critical that the concentrate produced by the evaporation of most acetic acid comes out through miÜÉJmi-jffliiti r i ni ir 1 i - * ^ - - - '- • - -. * .- .. ***. * .. * ..- *. * .. * .1 1 f ^^ m ^ of line 116 in the form of a liquid, which even when viscous, can still be pumped. During the evaporation process of acetic acid, 5 small amounts of water can be added continuously or intermittently through additive line 113. The addition of water can be critical in decreasing the amount of acetic acid in the concentrate to maintain the concentrate in a solid-free form, depending on the conversions, relative levels of 10 compounds in the concentrate, etc. fB The concentrate enters the middle stage 119 of the multi-stage countercurrent assembly 114 through line 116, which merges with a flow in the line 140 ', and then with a flow on line 142' ', ending in 15 the average mixer 118a. The three streams, from the lines 116, 140 ', and 142"are mixed well in the mixer 18a, and the resulting mixture is transferred to the separator 118 through the line 118a', where it is separated in a higher phase, delicious ^ in cyclohexanone, and a lower phase, rich in water. The phase The lower stage is directed towards the pre-mixer (intermediate mixer 140a) through line 118", while the upper phase is directed to the next mixer (intermediate mixer 142a) through line 118 '. Cyclohexanone is fed to the front mixer 25 124th through line 130, where it mixes well í é -jrff AfÉIHr • '- "- ..mi * m - *. mMim? t? mm * ?. Jm ** ^ **. *. * - m **. m *. -. ***. .. **. a, -. - * .... i *. * mM with a flow coming from the lower phase of the intermediate separator 140, through the line 140 '' The resulting mixture is fed to the separator front 124 through line 124a ', where it is separated in a lower phase, • 5 which leaves the assembly through line 132, and an upper phase, which is directed to intermediate mixer 140a through line 124 '. The lower phase leaving assembly 113 through line 132 is an extract comprising most of the 10 catalyst in an aqueous solution. This also contains H small amounts of cyclohexanone. In the back stage 122 of the assembly 114, the water enters the mixer 126a through the line 128, where it mixes well with a flow coming from the phase 15 of the intermediate separator 142 through the line 142 '. The resulting mixture is directed to separator 126 through line 126a ', where it is separated into a lower phase, and an upper phase. The lower phase is directed to the intermediate mixer 142a through the line 126", 20 while the upper phase leaves the assembly 114 through line 13. The upper phase, which leaves the assembly 114 through line 134, is a raffinate containing a solution of most of the concentrate in the cyclohexanone. 25 A small amount of water is also present. i lil l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l ** -, ** -. * • ** &- .- - *. *. *, As shown in Figure 2, the operation is based on successive stages of catalyst extraction to form a final catalyst extract watery, leaving the assembly 114 through line 132, and leaving behind a • refined concentrate in cyclohexanone, which leaves the assembly 114 through line 134. As the extraction solvent (water) moves from the rear separator 126 to the front separator 124, it is enriched in catalyst, leaving a 10 refined continuously more spent catalyst, which finally leaves the assembly 114 through the line 134.

• By this technique, the dissolution of the concentrate entering the multistage assembly in countercurrent through the line 116 is achieved with the 15 Simultaneous extraction of the metal catalyst in the form of a solution, by water. The refining and catalyst extract can be further treated and / or recycled as discussed in our previously mentioned patents and patent applications. 20 The introduction of the concentrate in the middle stage of the multi-stage counter-current or extractor assembly (or in the middle part of a similar counter-current column) is critical to maximize the efficiency and effectiveness of the catalyst extraction. 25 from the concentrate. The introduction of the concentrate in the middle stage 119 of the countercurrent multi-stage assembly 114, and not in the back stage 122, ensures that a considerable amount of the catalyst has been removed before the final extraction takes place in the separator. final 126. The introduction of the concentrate into the front stage 120 of the countercurrent multi-stage assembly or extractor 114, would result in a considerably greater incorporation of the concentrate fractions (other than the catalyst) in the 10 extract of the catalyst that comes out through line 132.? The entire metal catalyst can be extracted and removed substantially through the line 132 by controlling the temperature at the different stages, the feed rates through the 15 lines 128 and 130, and by the number of stages. Water entering line 128 may contain a lower amount of cyclohexanone, while cyclohexanone entering through line 130 may contain a smaller amount of water. Similarly, as 20 mentioned above, the extract of the catalyst exiting through the line 132 contains a minor amount of cyclohexanone, while the raffinate leaving through the line 134 contains a smaller amount of water. In the last stages of assembly to 25 countercurrent 114, close to the back stage 122, in When the last stages have rather low concentrations of the catalyst, the emulsion of the water and the cyclohexanone contained in the different products tend to occur, which allows small amounts of the product to be incorporated. • 5 catalyst in the refining, which leaves the assembly through line 134. In order to reduce or eliminate such tendency considerably, the temperature of the last stages must be greater than a certain critical temperature, which can be easily found without undue experimentation. Thus, all the stages can be maintained at a temperature higher than said critical temperature, or only the last stages, or only the rear stage 122. One way to achieve this easily, is by controlling the temperature of the various flows by means of a good means of control. known in the art, such as for example heaters, coolers, heat exchangers, etc. Of course, the separators or mixers can also be heated or cooled by similar techniques, such as for example, w by the use of internal or external devices for heating or cooling, and / or other means of temperature control. In case it is desirable to keep the entire multistage assembly countercurrent at approximately the same temperature, preferable temperatures are in the range of 50 ° C to 80 ° C.

IHHÜHÉ ^ É ^^^ Jil ^^^^^^^^^^^^^^^ MMM ^ Mapit im ÉÉ "ni ml mu mir - - | -? I - ^ ímá mm More preferably, however , the temperature of the rear stage 122 must be maintained in a range of 50 ° C to 90 ° C, the temperature of the middle stage 119 must be maintained in a range of 30 ° C to 50 ° C, and the temperature of the stage '5 front 120 must be maintained in a range of 10 ° C to 40 ° C. In the presence of intermediate stages, the intermediate stages should be maintained preferably at temperatures between the temperature of the middle stage and the respective end stage (front or rear) 10 If an unacceptable emulsion occurs in the back flip stage 122, or at any other stage, a centrifugal separator, such as the separator 126, shown in Figure 1, may be used instead of a simple decanter When a centrifugal separator is used at least in the rear stage, it is 15 less important to maintain the temperature above the critical emulsion points. It should be understood that, in accordance with the present invention, any or all of the • liquid, gas, or gas released from any section towards 20 any other section, if desired. In addition, any combination of the exemplified embodiments may be used, in part or totally, or any equivalent configuration or any combination of the equivalent configurations, and is within the scope of the invention. 25 present invention. í * j ^^^^ mmmmmmmmt * • ** -. ,. *. ***. ** - **** **. * Although many functions are preferably controlled by a computerized controller, it is possible, according to this invention, to use any other type of controller or even manual controls • 5 and / or labor to control one or more functions. Preferred computerized controllers include artificial intelligence systems (expert systems, neural networks, and polyvalent logic systems, well known in the art). Of these three types of intelligence systems 10 artificial, the neural network, which is a learning system, collects information from different places of the device (for example, pressure, temperature, chemical analyzes and other analyzes, etc.), stores this information together with the result (rate of fall of pressure, 15 reaction speed, reactivity, and the like, for example), and it is scheduled to use this information in the future, together with other applicable data, to make decisions regarding the action to be taken in TP each instance. Expert systems are programmed based on 20 in the experience of experienced human beings. The polyvalent logic system is based on rules of intuition in addition to the rules of experience. The oxidations according to the invention are not destructive oxidations, wherein the oxidation products 25 are different from carbon monoxide, carbon dioxide, and a mixture thereof, such as adipic acid for example. 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. • With respect to adipic acid, the preparation of which is especially suitable for the methods of this invention, general information can be found in a plethora of patents of the United States of North America, among other references. These include, but are not limited to 10 a: flp Patents of the United States of America Nos. 2,223,493; 2,589,648; 2,285,914; 3,231,608; 3,234,271; 3,361,806; 3,390,174; 3,530,185; 3,649,685; 3,657,334; 3,957,876; 3,987,100; 4,032,569; 4,105,856; 15 4,158,739 (glutaric acid); 4,263,453; 4,331,608; 4,606,863; 4,902,827; 5,221,800; and 5,321,157. They can react diacids (eg adipic acid, phthalic acid, isophthalic acid, acid • terephthalic, and the like) or other suitable compounds, According to techniques well known in the art, with a third reagent selected from a group consisting of a polyol, a polyamine, and a polyamide, in a manner to form a polyester polymer, or a polyamide, or a polyimide and / or polyamideimide, respectively. He 25 polyol, polyamine, and polyamide are preferably lylilflfilfilHlifaltfMl ^ MMM ^^ alfciatti mainly a diol, a diamine, and a diamide, respectively, in order to avoid excessive crosslinking. The polymer resulting from this reaction can be spun by techniques well known in the art to form fibers. The polymer can also be mixed with fillers and / or other additives to form composite materials. Examples have been given demonstrating the operation of the present invention only for purposes of 10 illustrate, and should not be construed to limit the scope of the invention in any way. In addition it should be emphasized that the preferred modalities discussed in detail hereinbefore, as well as any other modalities covered within the limits of the The present invention can be practiced individually, or in any combination thereof, according to common sense and / or opinion of an expert. You can also practice individual sections of the modalities, individually or in combination with other sections 20 individual modalities, or modalities in their entirety, in accordance with the present invention. These combinations also fall within the scope of the present invention. Moreover, any explanation sought in the discussion is only speculative and does not intend to narrow 25 the limits of this invention. m *. .** *to

Claims (1)

1. CLAIMS 1. A solution extraction method of a metal catalyst from a reaction mixture that is produced by the oxidation of cyclohexane to adipic acid in the presence of acetic acid and the metal catalyst, the method comprising the steps of : (a) remove substantially all of the cyclohexane; (b) remove most of the adipic acid; (c) removing most of the acetic acid, without precipitating the catalyst, thus forming a concentrate in solution; (d) introducing the concentrate into the middle part of a countercurrent flow, the countercurrent flow also having a lower part and an upper part, the lower part having a bottom, and the upper part having a top; (e) introducing cyclohexanone, which may comprise a smaller amount of water, towards the lower part of the countercurrent flow; (f) introducing water, which may comprise a minor amount of cyclohexanone in the upper part of the countercurrent flow; (g) removing a first liquid or refined from the top of the upper part, the first liquid comprising most of the concentrate, excluding the catalyst; and (h) withdrawing a second liquid or extract from the bottom of the bottom, the second liquid comprising most of the metal catalyst. 2. A method as defined in the claim 1, wherein steps (d), (e), (f), (g), and (h) are performed simultaneously. 3. A method as defined in any of claims 1 and 2, wherein step (c) is conducted 10 by distillation. 4. A method as defined in any of claims 1 to 3, which further comprises the step of adding water in step (c). 5. A method as defined in any of claims 1 to 4, wherein substantially all of the acetic acid is removed in step (c). 6. A method as defined in any of claims 1 to 5, wherein substantially all of the metal catalyst is removed in step (h). 7. A method as defined in any of claims 1 to 6, wherein the upper part has an upper part temperature, the middle part has a middle part temperature, the lower part has a lower part temperature, and where the temperature of The upper part, the temperature of the middle part, and the temperature of the lower part are substantially the same. 8. A method as defined in any of claims 1 to 6, wherein the upper part has a top temperature, the middle part has a middle temperature W * i, the lower part has a lower part temperature , and where the temperature of the upper part is higher than the temperature of the middle part. 9. A method as defined in claim 10 8, wherein the temperature of the middle part is greater than the lower temperature of the fJP. A method as defined in any of claims 1 to 9, which further comprises the step of reacting the adipic acid with a reagent selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner for forming a polymer of a polyester, or a polyamide, or a polyimide and / or polyamideimide, respectively, wherein the method can further comprise a step of spinning the polymer into fibers or mixing the polymer with fillers. and / or other additives to form compounds. 11. A solution extraction method of a metal catalyst from a reaction mixture that is produced by the oxidation of cyclohexane to adipic acid in the presence of acetic acid and the catalyst of t i iriiiii'iílWíTi'i metal, the method comprising the steps of: (k) removing substantially all of the cyclohexane; (1) remove most of the adipic acid; (m) remove most of the acetic acid, without precipitating the catalyst, forming a concentrate in solution; (n) introducing the concentrate into the middle stage of a countercurrent multi-stage assembly, the middle stage comprising a middle mixing zone and a medium separation zone, the multi-stage assembly also comprising a front stage and a stage rear, the front stage comprising a front mixing zone and a front separation zone, and the rear stage comprising a rear mixing zone and a rear separation zone; (p) introducing cyclohexanone, which may comprise a minor amount of water, in the frontal mixing zone; (q) introducing water, which may comprise a minor amount of cyclohexanone in the rear mixing zone; (r) removing a raffinate from the rear separation zone, the raffinate comprising a greater part of the concentrate, excluding the catalyst; and (s) withdraw an extract from the area of ^^ g ^ M ^^ l ^ g front separation, the extract comprising a greater part of the metal catalyst. 12. A method as defined in claim 11, wherein the step (m) is conducted by distillation. 13. A method as defined in any of claims 11 and 12, which further comprises the step of adding water in step (m). 14. A method as defined in any of claims 11 to 13, wherein, at least in the area of 0 rear separation, the separation is conducted at least partially by a centrifugation step. 15. A method as defined in any of claims 11 to 14, wherein the rear stage has a rear stage temperature, the middle stage has a middle stage temperature, the front stage has a front stage temperature, and wherein the temperature of the back stage, the temperature of the middle stage, and the temperature of the front stage are substantially equal. 16. A method as defined in claim 0 15, wherein the substantially equal temperature is in a range of 50 ° C to 80 ° C. 17. A method as defined in any of claims 1 to 14, wherein the rear stage has a rear stage temperature, the middle stage has a middle stage temperature, the front stage has a frontal stage temperature, and where the temperature of the rear stage is higher than the temperature of the middle stage, and the temperature of the middle stage is higher than the temperature of the front stage. 18. A method as defined in the claim 17, where the temperature of the rear stage is in the range of 50 ° C to 90 ° C, the temperature of the middle stage is in the range of 30 ° C to 50 ° C, and the temperature of the front stage is in the range of 10 ° C to 40 ° C. 19. A method as defined in any of claims 1 to 18, wherein substantially all of the acetic acid is removed in step (m). A method as defined in any of claims 1 to 19, wherein substantially all of the metal catalyst is removed in step (s). 21. A method as defined in any of claims 11 to 20, which further comprises the step of reacting the adipic acid with a reagent selected from a group consisting of a polyol, a polyamine, and a polyamide of a way to form a polymer of a polyester, or a polyamide, or a polyimide and / or polyamideimide, respectively, wherein the method may further comprise the step of spinning the polymer into fibers or mixing the polymer with fillers and / or other additives to form compounds. kmmmíd.mi. *. t? m * i. , * - * + *,. -, -,. . *. . . . .., .. * ..,. *. . * .. ,,. .-. «.. ^ J ^, i-.i.