MXPA00002543A - Manufacture of methyl isobutyl and diisobutyl ketone - Google Patents

Abstract

A method for the catalytic manufacture of MIBK and DIBK from DMK and/or IPA (optionally in the presence of water) while obtaining improved control over the ratio of DIBK to MIBK in the product stream, comprising reacting, in the presence of an aldol condensation catalyst, a reactant mixture comprising DMK and/or IPA and an effective amount of an additional reactant selected from the group consisting of mesityl oxide (MSO) and methyl isobutyl carbinol (MIBC) and mixtures thereof. Reaction temperature may also be changed to affect the product ratio obtained. The preferred catalyst is copper-based. An overall excess of hydrogen is desired, and this may be achieved by introducing or recycling hydrogen, and/or by balancing exothermic and endothermic reactions. By this invention, the product ratio of DIBK to MIBK is altered such that, as DMK and/or IPA conversion is increased, a lesser amount of DIBK than normal is produced, resulting in improved ability to control the product ratio of these materials.

Description

ETHYL TO DEACOPLATE METHYL ISOBUTYL CETONE AND DIOSBURETHYL CETONE COUPLED FROM ACETONE AND / OR ISOPROPYL ALCOHOL.

FIELD OF THE INVENTION This invention relates to the production of methyl isobutyl ketone (MIBK) and diisobutyl ketone (DIBK) by the catalytic reaction of acetone (DMK) and / or isopropyl alcohol (IPA). More specifically, this invention relates to a method for controlling the ratio of MIBK to DIBK produced.

COMPENDIUM OF THE. PREVIOUS TECHNIQUE MIBK and DIBK are well-known derivatives of acetone, and are frequently co-produced by the catalyzed reaction of DMK and / or IPA. Typically, an aldol condensation catalyst is used, a preferred embodiment of which is based on copper. The MIBK and DIBK occur at the exit of these processes in a natural relation one with respect to the other; however, this relationship is not constant, that is, the ratio of DIBK to MIBK increases as steps are taken to increase the production of MIBK. This phenomenon is illustrated by the Figure, which shows an empirically predetermined adjusted line that illustrates the DIBK / MIBK relationship as a function of the produced MIBK. Unfortunately, the needs of the market they do not necessarily conform to the natural tendencies of chemistry. In this way, as will be easily appreciated from the Figure, if it is desired to increase the production of MIBK to meet the demands of the market, an excessive amount of DIBK can be produced, resulting in the need to store or destroy a certain amount of the DIBK, and accept the inefficiencies and energy sanctions of the related raw material. Accordingly, it would be highly desirable that there be a method whereby the DIBK / MIBK ratio will be easily controlled by allowing the manufacturing operation to, in effect, "incorporate" the amount of any desired material and also obtain a more desired amount. of the other material, "decoupling" in this way the usual relationship between the production levels of these two products. The present invention provides this method.

BRIEF DESCRIPTION OF THE FIGURE The Figure illustrates the approximate DIBK / MIBK relationship that typically occurs at determined MIBK production rates.

COMPENDIUM OF THE INVENTION The present invention provides a method for the catalytic manufacturing of MIBK and DIBK from DMK and / or IPA (optionally in the presence of water) while an improved control is obtained through the ratios of DIBK to MIBK, which comprises reacting, in the presence of an aldol condensation catalyst, a reagent consisting of DMK and / or IPA (optionally in the presence of water), and an effective amount of an additional reagent that is selected from the group consisting of mesityl oxide (MSO) and methylisobutyl carbinol (MIBC) and mixtures thereof. By the term "effective amount" is meant an amount that results in a deviation in the DIBK / MIBK ratio from that shown in the Figure. Preferably, this deviation will be at least about 5 percent, most preferably at least about 10 percent. The reaction temperature can be increased or decreased, as desired, to effect a desired increase or decrease, respectively, in the conversion of DMK and / or IPA and correspondingly the ratio of DIBK / MIBK. The invention further comprises a method for the catalytic manufacturing of MIBK and DIBK from DMK and / or IPA, optionally in the presence of water, while an improved control is obtained through the ratio of DIBK to MIBK, which comprises making react, in the presence of an aldol condensation catalyst, a reagent that consists of DMK and / or IPA, and an effective amount of an additional reagent that is selected from the group consisting of mesityl oxide (MSO), methylisobutyl carbinol (MIBC), and mixtures thereof, and further comprising decreasing or increase the aldol condensation reaction rate by decreasing or increasing the reaction temperature. DESCRIPTION OF THE INVENTION Without wishing to be limited to any specific chemical theory, it is believed that the co-production of MIBK and DIBK from IPA and / or DMK involves the following reactions: (GPA) (DMK) (DMK) (MSO) (MSO) (MB3K) (MIBC) (DMK) (MTBK) (DIBK) It can be seen that the MSO and DIBK isomers exist and are probably present in the chemical mixture; however, they are not believed to be significant for the present invention, and are considered herein as normal MSO and DIBK, respectively. In accordance with the invention, MSO or MIBC or mixtures thereof, derived from sources external to the process, or optionally from appropriate recycle streams of the process, are co-fed to the reactor together with usual DMK and / or IPA and optionally water. Even when it is proposed that the MSO and / or MIBC used as the co-feed in the present invention, will be provided from sources external to the process, the MSO and / or MIBC produced within the total reaction chemistry noted above also it can be exploited to determine the desired amounts of those reagents necessary to carry out the present invention. It has surprisingly been found that the addition of supplementary MSO and / or MIBC, when appropriately controlled, together with the appropriate temperature control, as will be discussed more fully below, will result in predictable and favorable control of the DIBK ratio. MIBK. In other words, the DIBK / MIBK relationship can now be influenced in such a way that an amount is produced less than DIBK per unit of MIBK of the one shown in the Figure. This allows the manufacturing operators to select the level of the desired production of one or the other of those products without having the level of the other product inherently regulated. Either MSO or MIBC or mixtures thereof with each other or with other reagents in the system, may be coalesced at concentrations up to at least about 20 percent or more by weight of the total input stream to the reactor, including DMK, IPA and water if present. As will be understood by those skilled in the art, a reasonable degree of experimentation may be desirable in order to obtain satisfactory performance results in any given manufacturing system. The optimization of the related concentrations are considered as remaining within the skill of the technique, and will of course depend on the local operating conditions, such as the capacity of the reaction system to remove heat and hydrogen from external supply. Preferably, at least one of MSO or MIBC will be present in the inlet stream at a concentration of at least about 2 weight percent, more preferably at least about 5 weight percent.

As mentioned, a desired increase in the MIBK level has previously resulted in an excessive increase in the DIBK level. Since MSO and MIBC are easily converted to MIBK in the catalytic reaction, it was to be expected that the feeding of additional MSO and / or MIBC would result in excessive DIBK. Another surprising result of the present method is that this increase in DIBK does not occur, ie, that the DIBK / MIBK ratio that is expressed in the Figure has been favorably altered. The manipulation of the reaction temperature would further alter this relationship, and is an important option in the application of this invention. It will also be easy to observe that MSO is a by-product of the process; therefore, it is a surprising feature of the present invention that the external MSO could be fed into the process without resulting in an excess thereof in the products. MSO typically occurs in the product mixture at concentrations of about 0.5 weight percent or less, and is found to be particular as an impurity in MIBK because its boiling temperature is close to that of MIBK. Accordingly, it is a surprising advantage of the present invention to avoid producing MSO at significantly higher, and preferably even less than, those of the process the prior art. In fact, it has been found that even as much as about 20 percent by weight of additional MSO of the total feed mixture can be combined without experiencing an increase in the MSO in the product stream. As a preliminary approximation, it can be said that in a typical converter for which IPA is the raw material, approximately 0.454 kilogram of MSO and / or MIBC can be fed for each 0.454 kilogram of DMK that is made in the converter, and that approximately 90 percent or more of the MSO and / or MIBC will be consumed in the production of MIBK and DIBK. It should also be noted that the change in temperature will also change the DIBK / MIBK ratio, as will be discussed more fully below. As is clear from the reaction chemistry noted above, hydrogen is both a product and a reagent in the system. It is preferred that an excess of hydrogen be maintained. This condition is conveniently referred to as the hydrogen equilibrium. As will be recognized by those skilled in the art, the desired level of hydrogen can be achieved by the process such as feeding fresh hydrogen, or recycling unused or produced hydrogen.

In addition, the system has a certain capacity to remove heat. This condition is conveniently referred to as thermal equilibrium. If an excessive amount of MSO is fed into the system, the exothermic reaction between MSO and hydrogen will release an excessive amount of heat, deactivation of the catalyst may occur and hydrogen consumption will be excessive. In this way, typically, a manufacturing unit is limited in that so much MSO can be fed without breaking the hydrogen equilibrium and / or thermal or heat equilibrium to such an extent that the result is unacceptable. It will be appreciated that a better control of the reaction will be achieved if the total system is kept within an acceptable thermal equilibrium. In this way, it is desirable to take into account the stoichiometry of the aforementioned reactions, as well as the related heats of reaction. For a system that only has IPA as a raw material, the empirical rule for an ideal adiabatic system is that 0.454 kilogram of MSO can be fed for every 0.454 kilogram of DMK that is made by the system. This is because the heat for the production of DMK is approximately the same endothermic amount since the hydrogenation of MSO to MIBK is exothermic. This also keeps hydrogen in excess because 0.454 kilogram per hour of production of DMK produces approximately 0.00908 kilogram per hour of hydrogen, while the hydrogenation of MSO of 0.454 kilogram per hour consumes approximately .00454 kilogram per hour. Most systems are not ideal, of course, so that it may be possible to feed more MSO satisfactorily than suggested by the aforementioned analysis. In accordance with the present invention, it has been found that concerns about feeding an excessive amount of MSO can be alleviated by limiting the entry of MSO to the concentration levels discussed herein, and / or using a mixture of MSO and MIBC. Since the reaction of MSO with hydrogen gives off approximately 25.58 calories per gram of MIBK and the conversion of MIBC into MIBK acquires approximately 13.90 calories per gram of MIBK, it is evident that the exothermic reaction generated by the MSO reaction can be mitigated by diluting the MSO with MIBC to increase the endothermic generation of that reaction. The selection of the optimal ratio will, of course, be a matter of routine calculation and experiment within the skill of the technique. Even when the bi-functional copper-based aldol condensation catalyst is also capable of carrying out the hydrogenation / dehydrogenation chemistry of preference is used in the present method, the beneficial effects of the invention, as described above, are not considered to depend on any specific catalyst composition. Accordingly, any catalyst useful for the production of MIBK and / or DIBK from IPA and / or DMK should be understood as applicable. Included among these catalysts are those based on chromite of Pd, ZnO, Cu, and Al / Mg / Zn / Ni mixtures. These catalysts often have one or more base metals (eg, Na, Ca, Mg, Li and the like) for the condensation chemistry, in combination with one or more metals for example Cu, Cr, Ni, Pd or Zn, and the like , for the hydrogenation / dehydrogenation chemistry. The preferred catalyst, however, as used in the Examples to be given below, comprises about 10 percent Cu, about 1 percent Ca and about 0.5 percent Cr by weight of the metal, the rest being the support , preferably alumina. For the purposes of the present invention, the catalyst composition is not believed to be narrowly critical. For example, the concentration of the hydrogenation catalyst (eg, Cu, Cr, Ni, etc.) can be from about 5 percent to about 15 percent by weight, while the concentration of the base metal (eg, Ca, Na , Mg, etc.) it may be within the range of about 0.5 percent to about 3 percent by weight. With respect to the preferred catalyst composition described above, Cr is optional, and may vary from 0 percent to about 1 percent. Except as will be discussed below, in relation to the temperature change to improve control through the DIBK / MIBK ratio, the selection of the reaction temperature within the temperature operating envelope of the selected catalyst is not closely critical and can typically vary from about 150 ° C to about 300 ° C, preferably from about 180 ° C to about 270 ° C, more preferably from about 200 ° C to about 260 ° C. Temperatures above about 270 ° C, depending on the thermal stability of the specific catalyst in use, are preferably avoided in order to minimize deactivation of the catalyst. Obviously, lower temperatures are preferred due to that reason. Also, as the temperature increases, the equilibrium begins to drive the hydrogenation reactions towards MSO, causing the concentration of MSO to increase. The selection of the reaction pressure is not critical. An operation is suggested within the scale from approximately 0.703 to approximately 2.11 kilograms per square centimeter gauge. Separately, the rate of flow through the reactor is not narrowly critical, and can typically range from about 0.1 to at least about 10.0 LHSV, preferably from about 0.1 to at least about 3.0 LHSV. By the term "LHSV" it is meant the hourly space velocity of the Iliquid, a commonly used measure which is equal to the volumetric rate of the feed in the liquid state per volume of the catalyst. (as used in the Examples that will be given below, it should be noted that even when the measurement of LHSV is made at atmospheric pressure and in the liquid state the reaction was carried out in the gas phase and under pressure). Preferably, the flow rate will be within the range of about 0.5 to about 1.5 LHSV, and most preferably within the range of about 0.75 to about 1.25 LHSV. As also mentioned, increases or decreases in temperature can be imposed in the reaction in combination with the use of MSO and / or MIBC which is co-fed as the means to obtain additional control of the ratio of DIBK / MIBK; therefore, this invention also shows that the manipulation of the temperature together with the MSO / MIBC co-feeding can further improve the unit's ability to produce a wide scale of DIBK / MIBK relationships. As a theoretical example, suppose that the system was under typical operating conditions and the feed composition, and the system would therefore produce 13 percent of MIBK and 4 percent of DIBK. Now let's replace 10 percent by weight of the MSO feed. The system could then produce 20 percent of MIBK and 6.5 percent of DIBK. Historically, to reach 20 percent of MIBK, the system would have produced 8.5 percent of DIBK; therefore, approximately a relative reduction of 25 percent was obtained in DIBK. If the temperature in the above-mentioned theoretical example (ie, the typical operating conditions and with 10 percent MSO in the feed) is lowered to 15 ° C, the system could produce 17 percent MIBK and 4 percent percent of DIBK. Historically, to reach 17 percent of MIBK, the system would have produced 6 percent of DIBK; therefore, approximately a relative reduction of 33 percent was obtained in DIBK. Surprisingly, by co-feeding the MSO and altering the temperature, the MIBK is increased up to 30 percent without increasing the DIBK, as compared to the example with the typical reactor conditions and the feed composition. The additional handling of MSO / MIBC co-fed and the temperature could lead to increased MIBK production with decreased DIBK production. Without wishing to be bound to any specific chemical theory, a reasonable explanation for the result is the following. The hydrogenation / dehydrogenation reactions occur easily throughout the entire operating temperature scale. Condensation reactions depend on a large amount of temperature. Therefore, any amount of MSO / MIBC that is fed easily produces MIBK. However, if the temperature is lowered sufficiently, the condensation reaction of MIBK with DMK to form DIBK is significantly reduced.

Examples The examples given below are intended to illustrate the message but not to limit it in any way.

Example 1 Approximately 170 cubic centimeters per hour (LHSV = 0.85) of a mixture that was ~ 45 percent / 45 percent / 10 weight percent of DMK / IPA / H2O was fed to 200 cubic centimeters of a Cu-based catalyst at 220 ° C and pressure of 1,406 kilograms per square centimeter. The reactor product contained ~ 13.5 weight percent MIBK and 4.4 weight percent DIBK (DIBK / MIBK = 0.33). With all other reactor conditions remaining the same, the feed mix was changed to 39 percent / 39 percent / 9 percent / 13 percent DMK / IPA / H2O / MSO. The reaction product contained ~ 22.5 percent MIBK and 8.1 percent by weight of (DIBK / MIBK = 0.36). From the data shown in the Figure, the DIBK that would have resulted from carrying out the system the higher IPA / DMK conversion would have to have been 10.1 percent. Therefore, a relative reduction of 20 percent was obtained in the production of DIBK by co-feeding the MSO. Essentially there was no increase in the amount of MSO leaving the reactor.

Example 2 Approximately 150 cubic centimeters per hour of a mixture was fed which was ~ 45 percent / 45 percent / 10 percent DMK / IPA / H 0 to 200 cubic centimeters of a Cu-based catalyst at 220 ° C and pressure of 1,406 kilograms per square centimeter manometric The reaction product contained ~ 14.1 weight percent MIBK and 4.4 weight percent DIBK (DIBK / MIBK = 0.29). With all other reactor conditions remaining the same, the feed mix was changed to 40 percent / 40 percent / 10 percent / 10 percent DMK / IPA / H2O / MIBC. The reaction product contained ~ 18.7 percent MIBK and 5.4 percent by weight DIBK (DIBK / MIBK = 0.28). From the data shown in the Figure, the DIBK that would have resulted from operating the system at a higher IPA / DMK conversion would have been 7.3 percent. Therefore, a relative reduction of ~ 25 percent was obtained in the production of DIBK by co-feeding MIBC.

Example 3 Example 2 was further carried out with a decrease in temperature up to 210 ° C. The reaction product contained 14.3 percent MIBK and 2.2 percent DIBK. Therefore, by co-feeding MIBC and decreasing the temperature, the production of MIBK was maintained in comparison with the basic case of Example 2, while the production of DIBK is decreased by approximately 50 percent.

Example 4 Example 1 was carried out with the feed mixture which now contains 36 percent / 36 percent / 10 percent / 18 percent DMK / IPA / H20 / MSO. The catalyst has now been run for an additional week and had experienced some deactivation, which is in fact similar to the decrease in temperature. The reactor product now contained 25 percent MIBK and 5 percent DIBK (DIBK / MIBK = 0.2). From the data shown in the Figure, the DIBK would have resulted in operating the system at the highest IPA / DMK conversion would have been 12.6 percent. Therefore, a relative reduction of ~ 60 percent in DIBK production was obtained by co-feeding the MSO and effectively decreasing the reaction temperature. In fact, compared to the basic case in Example 1, the production of MIBK would have increased by approximately 85 percent without significantly increasing the production of DIBK.

Example 5 Approximately 190 cubic centimeters per hour (LHSV = 0.95) was fed from a mixture that was ~ 45 percent / 45 percent / 10 percent DMK / IPA / H2O to 200 cubic centimeters of a Cu-based catalyst at 250 ° C and pressure of 1,406 kilograms per square centimeter gauge. The reactor product contained 10.5 weight percent MIBK and 2.2 weight percent DIBK (DIBK / MIBK = 0.21). With all other reactor conditions remaining essentially the same, the feed mix was changed to 40 percent / 41 percent / 9 percent / 10 percent DMK / IPA / H2O / MSO. The reaction product contained 15.8 percent MIBK and 3.2 percent DIBK (DIBK / MIBK = 0.20). From the data shown in the Figure, the DIBK that would have resulted in operating the system at the highest IPA / DMK conversion would have been 5.4 percent. Therefore, a relative reduction of about 40 percent in the production of MIBK was obtained by co-feeding the MSO.

Example 6 Approximately 90 cubic centimeters per hour (LHSV = 0.45) was fed from a mixture that was 15 percent / 14 percent / 3 percent / 66 percent DMK / IPA / H20 / MIBC to 200 cubic centimeters of a catalyst based of Cu at 275 ° C and pressure of 1,406 kilograms per cubic centimeter gauge. The product of reactor contained 49 percent of MIBK and 16.5 percent of DIBK (DIBK / MIBK = 0.34). Therefore, with this mixture, significant increases were obtained in both the production of MIBK and DIBK without reaching relations not capable of handling DIBK / MIBK.

Claims (17)

CLAIMS:

1. A method for the catalytic manufacturing of MIBK and DIBK from DMK and / or IPA, and optionally water, while an improved control is obtained through the ratio of DIBK to MIBK, which comprises reacting, in the presence of a catalyst of aldol condensation, a reagent consisting of DMK and / or IPA and optionally water, and an effective amount of an additional reagent selected from the group consisting of mesityl oxide (MSO), methylisobutyl carbinol (MIBC), and mixtures thereof.

2. A method of claim 1, wherein the additional reagent results in a change in the DIBK / MIBK ratio of at least about 5 weight percent of that shown in the Figure.

3. A method of claim 2, wherein the additional reagent results in a change in the DIBK / MIBK ratio of at least about 10 percent of that shown in the Figure.

4. A method of claim 1, wherein the additional reagent is present in the inlet stream to the reactor at a concentration of at least about 2 weight percent.

5. A method of claim 1, wherein the additional reagent is present in the inlet stream to the reactor at a concentration of at least about 5 weight percent.

6. A method of claim 1, wherein the additional reagent comprises a mixture of MSO and MIBC.

7. A method of claim 1, wherein at least a portion of MSO or MIBC is present in the reaction mixture as a result of the reaction of DMK and / or IPA.

8. A method for the catalytic production of MIBK and DIBK from DMK and / or IPA, optionally in the presence of water, while an improved control is obtained through the ratio of DIBK to MIBK consisting of reacting, in the presence of an aldol condensation catalyst, a reagent consisting of DMK and / or IPA, and an effective amount of an additional reagent which is selected from the group consisting of mesityl oxide (MSO), methylisobutyl carbinol (MIBC) , and mixtures thereof, and further comprising reducing or increasing the reaction rate of aldol condensation by decreasing or increasing the reaction temperature.

9. A method of claim 8, wherein the ratio of DIBK to MIBK is lower than what would have been obtained in the absence of the additional reagent.

10. A method of claim 8 wherein the additional reagent consists of a mixture of MSO and MIBC.

11. A method of claim 8, wherein at least a portion of MSO or MIBC is present in the reaction mixture as a result of the reaction of DMK and / or IPA.

12. A method of claim 1, further comprising changing the DIBK / MIBK ratio by changing the reaction temperature.

13. A method of claim 8, further comprising changing the DIBK / MIBK ratio, changing the reaction temperature.

14. A method of claim 1, wherein LHSV is from about 0.5 to about 1.5.

15. A method of claim 8, wherein LHSV is from about 0.5 to about 1.5.

16. A method of claim 1, wherein the hydrogen is in an excessive amount.

17. A method of claim 8, wherein the hydrogen is in an excessive amount.