Method for producing ethanolamines and/or ethyleneamines

Abstract

Preparing ethanolamines/ethyleneamines in the presence of an amination catalyst prepared by reducing a calcined catalyst precursor containing one or more metals of groups 8, 9, 10 and/or 11 and low basicity achieved by: a) coprecipitating catalyst precursor and active composition additionally contains alkali metals or alkaline earth metals; b) the catalyst precursor is prepared by impregnating a support material or precipitative application onto a support material containing alkali metals, Be, Ca, Ba, Sr, hydrotalcite, chrysotile or sepiolite; c) the catalyst precursor is prepared by impregnating a support material or precipitative application onto a support material and the active composition of the catalyst support contains one or more of alkali metals and alkaline earth metals; d) the catalyst precursor is calcined at temperatures of 600 C. or more; or e) the catalyst precursor is prepared by a combination of a) and d), b) and d), or c) and d).

Claims

1. A process for preparing ethanolamines and/or ethyleneamines in the gas phase by reacting ethylene glycol (MEG) with ammonia in the presence of an amination catalyst which is prepared by reducing a calcined catalyst precursor comprising an active composition, where the active composition comprises one or more active metals selected from the group consisting of the elements of groups 8, 9, 10 and 11 of the Periodic Table of the Elements and optionally one or more added catalyst elements selected group consisting of the metals and semimetals of groups 3 to 7 and 12 to 17, the element P and the rare earth elements, wherein a) the catalyst precursor is prepared by coprecipitation and the active composition additionally comprises one or more basic elements selected from the group consisting of the alkali metals and alkaline earth metals, and the total amount of the basic elements is in the range from 2.5% to 80% by weight, based on the total mass of the catalyst precursor after calcination; or b) the catalyst precursor is prepared by precipitative application or impregnation of the active composition onto a support material, wherein the support material after calcination comprises one or more basic elements selected from the group consisting of the alkali metals, Be, Ca, Ba and Sr or one or more minerals selected from the group consisting of hydrotalcite, chrysotile and sepiolite; or c) the catalyst precursor is prepared by precipitative application or impregnation of the active composition onto a support material and the active composition of the catalyst support after calcination additionally comprises one or more basic elements selected from the group consisting of the alkali metals and the alkaline earth metals, and the total amount of the basic elements is in the range from 2.5% to 80% by weight, based on the total mass of the catalyst precursor after calcination; or d) the catalyst precursor is calcined at temperatures of 900 C. or more; or e) the catalyst precursor is prepared by a combination of variants a) and d) or by a combination of variants b) and d) or by a combination of variants c) and d); wherein the acidity of the calcined catalyst precursor is less than 0.2 mmol/g NH.sub.3, measured by temperature-programmed desorption of ammonia.

2. The process according to claim 1, wherein MEG and NH.sub.3 are reacted in the gas phase at a pressure in the range from 0.5 to 3 MPa and at a temperature in the range from 200 to 350 C.

3. The process according to claim 1, wherein the reaction is effected by contacting a gas stream comprising MEG and NH.sub.3 in a fixed bed reactor with the amination catalyst, and the gas hourly space velocity (GHSV) which is contacted with the amination catalyst is 1000 to 30 000 h.sup.1.

4. The process according to claim 1, wherein ethylene glycol and ammonia are reacted over the amination catalyst in the presence of hydrogen.

5. The process according to claim 4, wherein the proportion by volume of hydrogen in the gas stream which is contacted with the amination catalyst is in the range from 5% to 25% by volume.

6. The process according to claim 1, wherein the catalyst precursor is calcined in variant d) at a temperature in the range from 900 to 1200 C.

7. The process according to claim 6, wherein the catalyst precursor is calcined in variant d) at a temperature in the range from 900 to 1100 C.

8. The process according to claim 1, wherein the catalyst precursor is prepared by variants b) or c) and comprises the active metal Cu.

9. The process according to claim 1, wherein the catalyst precursor comprises one or more added catalyst elements selected from the group consisting of Zr and Zn.

10. The process according to claim 1, wherein the basic elements in variants a) and c) of claim 1 comprise one or more elements selected from the group consisting of K, Mg, Ca, Cs, and Ba and/or wherein the active composition of the catalyst precursor of variant d) further comprises one or more basic elements selected from the group consisting of K, Mg, Ca, Cs, and Ba.

11. The process according to claim 1, wherein the catalyst precursor in variants b) and d) of claim 1 comprises a support material which is a mixed oxide of CaO and ZnO.

12. The process according to claim 1, wherein the catalyst precursor is prepared by precipitative application or impregnation and comprises 2.5% to 60% by weight of Cu; 2.5% to 60% by weight of Zn and/or 0.1% to 10% by weight of Zr; and 2.5 to 60% by weight of Ca, based in each case on the total mass of the catalyst precursor after calcination.

13. The process according to claim 11, wherein the catalyst precursor is prepared by precipitative application or impregnation and comprises 40% to 95% by weight, based on the total mass of the catalyst precursor after calcination, of the mixed oxide according to claim 12, and where the composition of the catalyst precursor is 1% to 20% by weight of Cu, 20% to 60% by weight of Zn, 0.1% to 10% by weight of Zr and 10% to 60% by weight of Ca, based in each case on the total mass of the catalyst precursor after calcination.

14. The process according to claim 7, wherein the catalyst precursor is prepared by a combination of variants a) and d) or by a combination of variants b) and d) or by a combination of variants c) and d).

Description

(1) The invention is illustrated by the following examples:

Preparation of the Catalyst Precursors

Comparative Example 1: Calcination of the Catalyst Precursor at Low Temperatures

(2) 467 g of an aqueous copper nitrate solution (CuO content: 19.3% by weight) and 581.7 g of an aqueous zinc nitrate solution (ZnO content: 17.2% by weight) and 49.3 g of an aqueous zirconium acetate solution (ZrO.sub.2 content: 20.3% by weight) were mixed and precipitated with NaOH at a pH of 5 and a temperature of 80 C. After the precipitation, the pH was increased to 8 and the mixture was left at that pH for 15 minutes. Subsequently, the precipitated solids were filtered off and washed. The filter residue was dried at 120 C. for 16 hours. After the drying, the dried pulverulent residue was heated up to 500 C. (heating rate 10 K/min) and calcined at 500 C. for 120 minutes.

(3) The metal content of the catalyst precursor thus obtained was 33% by weight of Cu, 38% by weight of Zn and 3.4% by weight of Zr.

Example 1: Calcination of the Catalyst Precursor at High Temperatures

(4) The preparation was analogous to comparative example 1, except that the dried pulverulent residue was heated up to 900 C. (heating rate 10 K/min) and calcined at 900 C. for 120 minutes.

(5) The metal content of the catalyst precursor thus obtained was 36% by weight of Cu, 41% by weight of Zn and 3.8% by weight of Zr.

Comparative Example 2: Calcination of the Catalyst Precursor at Low Temperatures

(6) 103.8 g of copper nitrate solution (CuO content: 19.3% by weight) and 336.9 g of calcium nitrate were mixed with 300 mL of water. Thereafter, 100 g of y-alumina powder were mixed with water. The metal salt solution prepared beforehand was added to the aqueous alumina suspension. A pH of 5 was established by adding NaOH, which resulted in precipitation. After the precipitation, the pH was increased to 8 and the mixture was left at that pH for 15 minutes. Subsequently, the precipitated solids were filtered off and washed. The filter residue was dried at 120 C. for 16 hours. After the drying, the dried residue was heated up to 500 C. (heating rate 10 K/min) and calcined at 500 C. for 120 minutes.

(7) The metal content of the catalyst precursor thus obtained was 16.8% by weight of Al, 21.4% by weight of Ca and 6.4% by weight of Cu.

Example 2: Calcination of the Catalyst Precursor at High Temperatures

(8) The preparation was analogous to comparative example 2, except that the dried residue was heated up to 900 C. (heating rate 10 K/min) and calcined at 900 C. for 120 minutes.

(9) The metal content of the catalyst precursor thus obtained was 19.9% by weight of Al, 25.5% by weight of Ca and 7.6% by weight of Cu.

Comparative Example 3: Calcination of the Catalyst Precursor at Low Temperatures

(10) 200 g of Siliperl AF 125 (spall: 250-500 m) were impregnated with 152 mL of a metal salt solution having the following composition: 45% by weight of CuO from copper nitrate, 50% by weight of ZnO from zinc nitrate, 5% by weight of ZrO2 from zirconium acetate). The amount of metal salt solution used corresponds to 95% of the maximum water absorption of the catalyst support. After the impregnation, the catalyst precursor was dried at 120 C. for 16 hours. Thereafter, the dried catalyst precursor was heated to 500 C. (heating rate 10 K/min) and calcined at 500 C. for 120 minutes.

(11) The metal content of the catalyst precursor thus obtained was 10.9% by weight of Cu, 12.6% by weight of Zn and 1.1% by weight of Zr.

Example 3: Calcination of the Catalyst Precursor at High Temperatures

(12) The preparation was analogous to comparative example 3, except that the dried residue was heated up to 900 C. (heating rate 10 K/min) and calcined at 900 C. for 120 minutes.

(13) The metal content of the catalyst precursor thus obtained was 10.9% by weight, 12.8% by weight of Zn and 1.1% by weight of Zr.

Reaction of MEG and NH.SUB.3

Example 4

(14) The calcined catalyst precursors were tableted and converted to spall and sieved so as to obtain its size distribution of the particles in the powder of 0.315 to 0.5 mm.

(15) The powder was introduced into a tubular reactor and fixed with two quartz frits.

(16) The diameter of the fixed catalyst bed was 4 mm and the length 80 mm.

(17) The tubular reactor was heated up to the reaction temperature specified in table 1.

(18) Ammonia was evaporated into a gas stream of nitrogen and hydrogen (for hydrogen content see table 1) in a first evaporator. The evaporation temperature was chosen such that the amount of ammonia in the gas stream corresponds to the amount specified in table 1. In a second evaporator, MEG was evaporated into the gas stream. The evaporation temperature was chosen such that the amount of MEG in the gas stream corresponds to the amount specified in table 1.

(19) The gas stream was heated to the temperature specified in table 1 and passed through the reactor at 10 bar.

(20) The gas hourly space velocity (GHSV) was 5000 h.sup.1.

(21) The composition of the gas stream was determined by gas chromatography and is reported in table 1.

(22) TABLE-US-00001 TABLE 1 Comparative Comparative Comparative example 1 Example 1 example 2 Example 2 example 3 Example 3 T [ C.] 250 250 250 250 250 250 % by vol. of H2 20 20 40 40 20 20 % by vol. of NH3 40 40 40 40 40 40 CB % 80.9 93.8 96.0 98.1 89.2 96.8 MEG conversion 48.4 18.9 13.9 8.2 16.0 6.4 (%) EDA yield 9.0 3.2 5.1 2.9 1.42 1.53 (%) MEA yield 6.5 8.4 1.6 3.1 0.61 1.32 (%) PIP yield 8.4 0.7 2.7 0.3 1.42 0.19 (%) Acidity (NH.sub.3 uptake 0.044 0 0.31 0.066 0.262 0.031 in mmol/g) Total selectivity S* 49.3 65.0 68.0 77.3 21.5 47.3 (%) Selectivity quotient 1.08 4.49 1.8 8.5 1.01 8.18 SQ** *Total selectivity S = yield (MEA + EDA + DETA + PIP + AEEA)/conversion(MEG) 100 **Selectivity quotient SQ = yield(EDA + DETA)/yield(AEEA + PIP)

(23) In the case of catalyst precursors with identical composition, it was solely through the calcination at higher temperatures that it was possible to distinctly increase the ratio of desired linear products (MEA and EDA) to PIP, measured by the selectivity quotient SQ. It was also possible to improve the carbon balance (CB). The improvement in the carbon balance is an indication that both the formation of low molecular weight breakdown products undetectable by GC and the formation of high molecular weight condensates likewise undetectable by GC have been reduced. Particularly the high molecular weight condensates can lead to deposits on the catalyst that can reduce the activity of the catalyst.

Preparation of the Catalyst Precursors

Comparative Example 5: Catalyst Precursor with No Basic Component

(24) 467 g of an aqueous copper nitrate solution (CuO content: 19.3% by weight) and 581.7 g of an aqueous zinc nitrate solution (ZnO content: 17.2% by weight) and 49.3 g of an aqueous zirconium acetate solution (ZrO.sub.2 content: 20.3% by weight) were mixed and precipitated with NaOH at a pH of 5 and a temperature of 80 C. After the precipitation, the pH was increased to 8 and the mixture was left at that pH for 15 minutes. Subsequently, the precipitated solids were filtered off and washed. The filter residue was dried at 120 C. for 16 hours. After the drying, the dried pulverulent residue was heated up to 500 C. (heating rate 10 K/min) and calcined at 500 C. for 120 minutes.

(25) The metal content of the catalyst precursor thus obtained was 33% by weight of Cu, 38% by weight of Zn and 3.4% by weight of Zr.

Example 5A: Catalyst Precursor Comprising a Basic Component by Coprecipitation

(26) Procedure analogous to comparative example 4, except with replacement of a portion of the copper nitrate and zirconium acetate by calcium nitrate*4H.sub.2O, such that the starting solution used was a mixture of 102.4 g of a copper nitrate solution (CuO content: 19.3% by weight), 558.3 g of a zinc nitrate solution (ZnO content: 17.2% by weight), 336.9 g of calcium nitrate*4H.sub.2O in 400 mL of water.

(27) The metal content of the catalyst precursor thus obtained was 6.1% by weight of Cu, 30% by weight of Zn and 21.2% by weight of Ca.

Example 5B: Catalyst Precursor by Impregnation of a Basic Support Material

(28) An impregnation solution was prepared by mixing an aqueous copper nitrate solution (CuO content: 19.3% by weight) and 5 of an aqueous zirconium acetate solution (ZrO.sub.2 content: 20.3% by weight), such that the ratio of Cu:Zr in the solution obtained was 90:10.

(29) 100 g of a support material (composition: 56% by weight of ZnO; 44% by weight of CaO) (particle size: 315-500 m) were impregnated with 33.5 mL of the impregnation solution. The impregnated catalyst precursor was dried at 120 C. for 16 hours. After the drying, the dried catalyst precursor was heated up to 500 C. (heating rate 10 K/min) and calcined at 500 C. for 120 minutes.

Example 5C: Catalyst Precursor by Impregnation of a Basic Support Material

(30) The impregnation solution was prepared by mixing copper nitrate and water, such that the theoretical CuO oxide content of the solution was 19.3% by weight.

(31) 100 g of a support material (composition: 56% by weight of ZnO; 44% by weight of CaO) (particle size: 315-500 m) were impregnated with 33.5 mL of the impregnation solution. The further treatment of the catalyst precursor was conducted analogously to example 5B. Reaction of MEG and NH.sub.3

Reaction of MEG and NH.SUB.3

Example 6

(32) The calcined catalyst precursors were conditioned so as to obtain a size distribution of the particles in the powder of 0.315 to 0.5 mm.

(33) The powder was introduced into a tubular reactor and fixed with two quartz frits.

(34) The diameter of the fixed catalyst bed was 4 mm and the length 80 mm.

(35) The tubular reactor was heated up to the reaction temperature specified in table 2.

(36) Ammonia was evaporated into a gas stream of nitrogen and hydrogen (for hydrogen content see table 2) in a first evaporator. The evaporation temperature was chosen such that the amount of ammonia in the gas stream corresponds to the amount specified in table 1. In a second evaporator, MEG was evaporated into the gas stream. The evaporation temperature was chosen such that the amount of MEG in the gas stream corresponds to the amount specified in table 2.

(37) The gas stream was heated to the temperature specified in table 2 and passed through the reactor at 10 bar.

(38) The gas hourly space velocity (GHSV) was 5000 h.sup.1.

(39) The composition of the gas stream was determined by gas chromatography and is reported in table 2.

(40) TABLE-US-00002 TABLE 2 Comparative Example Example Example example 5 5A 5B 5C T [ C.] 250 250 250 250 % by vol. of H2 20 20 20 40 CB % 80.9 92.6 93.2 94.6 MEG conversion (%) 48.4 22.0 15.9 14.4 EDA yield (%) 9.0 4.5 2.9 2.7 MEA yield (%) 6.5 8.5 5.7 5.9 PIP yield (%) 8.4 0.6 0.3 0.2 Acidity (NH.sub.3 uptake 0.044 0 0 0 in mmol/g) Total selectivity S* 49.3 61.8 55.4 60.7 (%) Selectivity quotient 1.08 7.7 11.2 11.3 SQ** *Total selectivity S = yield (MEA + EDA + DETA + PIP + AEEA)/conversion(MEG) 100 **Selectivity quotient SQ = yield(EDA + DETA)/yield(AEEA + PIP)

(41) It is apparent from the table that catalyst precursors that have been obtained in accordance with the invention by impregnating a basic support material or that have been obtained by coprecipitation and comprise a basic component in the active composition lead to a distinct increase in the selectivity quotient SQ in the reaction of MEG with NH.sub.3. An increase in the selectivity quotient SQ means that the ratio of the desired linear amination products MEA and EDA has risen significantly in relation to the unwanted amination product PIP. Moreover, the carbon balance is significantly improved. The improvement in the carbon balance is an indication that both the formation of low molecular weight breakdown products undetectable by GC and the formation of high molecular weight condensates likewise undetectable by GC has been reduced. Particularly the high molecular weight condensates can lead to deposits on the catalyst that can reduce the activity of the catalyst.