Method for producing ethyleneamines

Abstract

The invention relates to processes for preparing alkanolamines and ethyleneamines in the liquid phase, by reacting ethylene glycol and/or monoethanolamine with ammonia in the presence of an amination catalyst comprising one or more active metals selected from Sn and the elements of groups 8, 9, 10 and 11 of the Periodic Table of the Elements, wherein the amination catalyst is obtained by reductive calcination of a catalyst precursor. The catalyst precursor here is preferably prepared by contacting a conventional or catalytic support material with one or more soluble compounds of the active metals and optionally one or more soluble compounds of added catalyst elements. The present invention further relates to a process for preparing an amination catalyst comprising one or more active metals selected from Sn and the elements of groups 8, 9, 10 and 11 of the Periodic Table of the Elements, the amination catalyst being obtained by reductive calcination of a catalyst precursor, wherein the reactor in which the catalyst precursor is reductively calcined is connected to a denox plant, and to the use of a denox plant in the preparation of amination catalysts.

Claims

1. A process for preparing alkanolamines and/or ethyleneamines in a liquid phase, by reacting ethylene glycol and/or monoethanolamine with ammonia in the presence of an amination catalyst comprising one or more active metals selected from Sn and the elements of groups 8, 9, 10 and 11 of the Periodic Table of the Elements, wherein the preparation of the amination catalyst consisting essentially of the following steps: (i) preparing a catalyst precursor by contacting a conventional or catalytic support material with one or more soluble compounds of the active metals and optionally one or more soluble compounds of added catalyst elements; (i)(a) optionally a work-up step comprising one or more of the steps of separation, washing and drying; (ii) reductively calcining the catalyst precursor obtaining in step (i), where the reductive calcination is effected in the presence of hydrogen and the oxygen content in the reductive calcination is less than 0.1% by volume; (iii) passivating the reductively calcined catalyst precursor from step (ii); (iv) activating the passivated catalyst from step (iii).

2. The process according to claim 1, wherein the catalytic or conventional support material is contacted with the soluble compounds of the active metals and optionally with the soluble compounds of the added catalyst elements by soaking or impregnation.

3. The process according to claim 1, wherein the one or more active metals are selected from the group consisting of Co, Ru, Sn, Ni and Cu.

4. The process according to claim 1, wherein one of the one or more active metals is Ru or Co.

5. The process according to claim 1, wherein the soluble compounds of the active metals that are contacted with the support material are used partly or completely in the form of their nitrates or nitrosylnitrates.

6. The process according to claim 1, wherein the support material comprises Al and/or Zr.

7. The process according to claim 1, wherein the support material is contacted simultaneously or successively with a soluble Ru compound and a soluble Co compound, where the soluble cobalt compound is Co nitrate.

8. The process according to claim 1, wherein the reactor in which the reductive calcination is conducted is a shaft reactor, rotary furnace, staged furnace or fluidized bed reactor.

9. The process according to claim 1, wherein the temperature in the reductive calcination is in the range from 100 to 300° C.

10. The process according to claim 1, wherein the reductive calcination is effected in a reactor connected to a denox plant.

11. The process according to claim 1, that the temperature in the activation is in the range from 100 to 300° C.

12. The process according to claim 1, wherein the reductive calcination is in the presence of hydrogen and an inert gas.

13. The process according to claim 12, wherein hydrogen is present in an amount from 1 to 50% by volume.

14. The process according to claim 12, wherein hydrogen is present in an amount from 2.5% to 30% by volume.

15. The process according to claim 12, wherein hydrogen is present in an amount from 5% to 25% by volume.

16. The process according to claim 1, wherein the catalyst precursor is prepared by coprecipitation and comprise the active metals Ru, Co and Sn.

17. The process according to claim 1, wherein the catalyst precursor comprises: 0.01% to 20% by weight of catalytically active components of Ru, calculated as RuO; 1% to 50% by weight of catalytically active components of Co, calculated as CoO; and 0.1% to 5% by weight of catalytically active components of Sn, calculated as SnO.

18. The process according to claim 1, wherein the catalyst precursor comprises: 1% to 10% by weight of catalytically active components of Ru, calculated as RuO; 20% to 40% by weight of catalytically active components of Co, calculated as CoO; and 1% to 3% by weight of catalytically active components of Sn, calculated as SnO.

19. A process for preparing alkanolamines and/or ethyleneamines in a liquid phase, by reacting ethylene glycol and/or monoethanolamine with ammonia in the presence of an amination catalyst comprising one or more active metals selected from Sn and the elements of groups 8, 9, 10 and 11 of the Periodic Table of the Elements, wherein the preparation of the amination catalyst comprises the following steps: (i) preparing a catalyst precursor by contacting a conventional or catalytic support material with one or more soluble compounds of the active metals and optionally one or more soluble compounds of added catalyst elements; (i)(a) optionally a work-up step comprising one or more of the steps of separation, washing and drying; (ii) reductively calcining the catalyst precursor obtaining in step (i), where the reductive calcination is effected in the presence of hydrogen and the oxygen content in the reductive calcination is less than 0.1% by volume and the reductive calcination is at a temperature of 100 to 280° C.; (iii) passivating the reductively calcined catalyst precursor from step (ii); (iv) activating the passivated catalyst from step (iii), with the proviso that an oxidation calcination is not carried out in the process.

20. The process according to claim 1, which requires the work-up step comprising one or more of the steps of separation, washing and drying.

Description

COMPARATIVE EXAMPLE 1

(1) 85.62 g of cobalt nitrate hexahydrate were dissolved in about 80 ml of hot demineralized water and 269.75 g of Ru nitrosylnitrate solution (16% by weight of Ru) were added thereto. The solution thus obtained was made up to a total of 371 mL with demineralized water.

(2) The metal salt solution thus obtained was transferred to a spray vessel.

(3) 500 g of Al2O3 support (1-2 mm spall) were calcined under an air atmosphere at 900° C.

(4) Thereafter, the maximum water absorption of the support was determined. This was 0.78 mL/g. The spall was impregnated with the metal salt solution prepared beforehand. The amount of the solution corresponds to 95% of the maximum water absorption of the spall.

(5) The spall impregnated with the metal salt solution was then dried at 120° C. in an air circulation drying cabinet for 12 h.

(6) After the drying, the catalyst precursor was oxidatively calcined at 600° C. in the presence of air.

(7) After the oxidative calcination, the catalyst was reduced by passing a gas stream of hydrogen over the catalyst precursor at 200° C. for about 6 hours.

(8) After the reduction, the catalyst was passivated by passing a gas stream of 98 L (STP)/h of N2 and 2 L (STP)/h of air over the catalyst at room temperature. The amount of air was increased gradually, while the amount of N2 was reduced slowly, until 20 L (STP)/h of N2 and 18 L (STP)/h of air were attained. The increase in the amount of air was conducted in such a way that the catalyst temperature did not exceed 35° C.

COMPARATIVE EXAMPLE 2

(9) The catalyst precursor was prepared according to example B3 of WO 2013/072289. Accordingly, the catalyst precursors were oxidatively calcined at a temperature of 450° C. with passage of air. Prior to the reduction of the tablets thus prepared, they were comminuted to 1-2 mm spall.

(10) The catalyst precursor thus obtained was reduced by the following method (see table 1):

(11) TABLE-US-00001 TABLE 1 Duration Temperature Nitrogen Hydrogen Air (min) (° C.) (L (STP)/h) (L (STP)/h) (L STP)/h) Remarks 1 30 min RT 100 — — Purge operation at RT 2 44 min 220 95 5 — Heating to 200° C. 3 120 min  220 95 5 — Hold time at 220° C. 4 30 min 280 95 5 — Heating to 280° C. 5 15 min 280 95 5 — Increase in the amount of hydrogen 6 15 min 280 90 10 — Increase in the amount of hydrogen 7 15 min 280 80 20 Increase in the amount of hydrogen 8 15 min 280 70 30 Increase in the amount of hydrogen 9 15 min 280 60 40 Increase in the amount of hydrogen 10 15 min 280 50 50 Cooling operation to RT 11 120 min  280 50 50 Hold time at 280° C.

(12) The reduction was followed by passivation of the catalyst precursor. For this purpose, a stream of 50 L (STP)/h of N2 and 0 L (STP)/h of air was passed over the reduced catalyst precursor. The amount of air was increased gradually, while the amount of N2 was reduced slowly, until 20 L (STP)/h of N2 and 20 L (STP)/h of air were attained. The increase in the amount of air was conducted in such a way that the catalyst temperature did not exceed 35° C.

COMPARATIVE EXAMPLE 3

(13) The catalyst precursor was prepared according to example B3 of WO 2013/072289.

(14) The tablets thus obtained (3*3 mm) were comminuted to 1-2 mm spall. The water absorption of the spall was 0.25 mL/g.

(15) A metal salt solution was prepared. For this purpose, 9.39 g of cobalt nitrate hexahydrate (20.25% by weight of Co) were dissolved in hot water, and 24.58 g of Ru nitrosylnitrate solution were added. The solution thus obtained was made up to 45 mL with demineralized water and transferred to a spray vessel.

(16) The spall was sprayed in an impregnating apparatus with an amount corresponding to 90% of the maximum water absorption of the spall. Thereafter, the catalyst spall was dried in an air circulation drying cabinet at 120° C. for 16 h.

(17) After the drying, the catalyst precursor was oxidatively calcined at 600° C. in the presence of air.

(18) The catalyst precursor thus obtained was reduced by the following method (see table 2):

(19) TABLE-US-00002 TABLE 2 Duration Temperature Nitrogen Hydrogen Air (min) (° C.) (L (STP)/h) (L (STP)/h) (L (STP)/h) Remarks 1 30 min RT 100 — — Purge operation at RT 2 44 min 220 95 5 — Heating to 220° C. 3 120 min  220 95 5 — Hold time at 220° C. 4 30 min 280 95 5 — Heating to 280° C. 5 15 min 280 95 5 — Increase in the amount of hydrogen 6 15 min 280 90 10 — Increase in the amount of hydrogen 7 15 min 280 80 20 Increase in the amount of hydrogen 8 15 min 280 70 30 Increase in the amount of hydrogen 9 15 min 280 60 40 Increase in the amount of hydrogen 10 15 min 280 50 50 Cooling operation to RT 11 120 min  280 50 50 Hold time at 280° C.

(20) After the reduction, the catalyst precursor was passivated. To this end, a stream of 50 L (STP)/h of N2 and 0 L (STP)/h of air was passed over the catalyst precursor. The amount of air was increased gradually, while the amount of N2 was reduced slowly, until 20 L (STP)/h of N2 and 20 L (STP)/h of air were attained. The increase in the amount of air was conducted in such a way that the catalyst temperature did not exceed 35° C.

Example 1

(21) 85.62 g of cobalt nitrate hexahydrate were dissolved in about 80 ml of hot demineralized water and 269.75 g of Ru nitrosylnitrate solution (16% by weight of Ru) were added thereto. The solution thus obtained was made up to a total of 371 mL with demineralized water.

(22) The metal salt solution thus obtained was transferred to a spray vessel.

(23) 500 g of Al2O3 support (1-2 mm spall) were calcined under an air atmosphere at 900° C.

(24) Thereafter, the maximum water absorption of the support was determined. This was 0.78 mL/g.

(25) The spall was impregnated with the metal salt solution prepared beforehand. The amount of the solution corresponds to 95% of the maximum water absorption of the spall.

(26) The spall impregnated with the metal salt solution was then dried at 120° C. in an air circulation drying cabinet for 12 h.

(27) After the drying, the catalyst precursor was reductively calcined under the conditions listed in table 1.

(28) TABLE-US-00003 TABLE 3 Heating Duration Temperature rate Gas flow | Gas flow (L (STP)/h) (min) (° C.) (° C./min) Nitrogen Hydrogen Air Remarks 1 30 min RT none 100 — — Purge operation at RT 2 150 min  150 1 95 5 — Heating to 150° C. 3 120 min  150 none 95 5 — Hold time at 150° C. 4 50 min 1 95 5 — Heating to 150° C. 5 15 min 200 none 95 5 — Increase in the amount of hydrogen 6 15 min 200 none 90 10 — Increase in the amount of hydrogen 7 15 min 200 none 80 20 Increase in the amount of hydrogen 8 15 min 200 none 70 30 Increase in the amount of hydrogen 9 15 min 200 none 60 40 Increase in the amount of hydrogen 10 15 min 200 none 50 50 Cooling operation to RT 11 120 min  200 none 50 50 Hold time at 200° C.

(29) After the reductive calcination, the catalyst was passivated by passing a gas stream of 98 L (STP)/h of N2 and 2 L (STP)/h of air over the catalyst at room temperature. The amount of air was increased gradually, while the amount of N2 was reduced slowly, until 20 L (STP)/h of N2 and 18 L (STP)/h of air were attained. The increase in the amount of air was conducted in such a way that the catalyst temperature did not exceed 35° C.

Example 2

(30) A catalyst precursor was prepared according to example B3 of WO 2013/072289.

(31) The tablets thus obtained (3*3 mm) were comminuted to 1-2 mm spall. The water absorption of the spall was 0.30 mL/g.

(32) A metal salt solution was prepared. For this purpose, 20.25 g of cobalt nitrate hexahydrate (20.25% by weight of Co) were dissolved in hot water, and 37.91 g of Ru nitrosylnitrate solution were added. The solution thus obtained was made up to 71 mL with demineralized water and transferred to a spray vessel.

(33) The spall was sprayed in an impregnation apparatus with an amount that corresponds to 95% of the maximum water absorption of the spall. In order to ensure homogeneous uptake of the impregnation solution, the spall was rotated for a further 30 min.

(34) Thereafter, the catalyst spall was dried in an air circulation drying cabinet at 120° C. for 16 h.

(35) The catalyst precursor thus obtained was reductively calcined and passivated as described in example 1.

(36) Catalyst Testing:

(37) The catalysts were tested in a continuously operated parallel plant on the pilot plant scale. The reaction part of the plant consists of eight individual reactors, of which four each are encompassed within one reactor block (heating block). Each individual reactor is a stainless steel tube of length 1.5 m with an internal diameter of 8 mm. The tubes are installed in an electrically heated reactor block consisting of an Al—Mg alloy.

(38) The catalyst was introduced into the reactor in the form of spall (1.5 mm-2 mm) and borne on an inert bed of length about 33 cm consisting of glass beads of size 3 mm.

(39) Above the catalyst bed there is a further, adjoining inert bed of length 15 cm consisting of glass beads of size 3 mm.

(40) The catalyst and the inert bed were fixed in the reactor by a fabric wire of length 1 cm.

(41) Each reactor was operated in straight pass and the flow was from the bottom.

(42) The liquid reactant was supplied from a reservoir with the aid of an HPLC pump. Hydrogen, nitrogen and ammonia were supplied through separate pipelines.

(43) Samples of the liquid reactor outputs were taken from a separator beyond the reactor exit. The reaction outputs were analyzed by gas chromatography.

(44) The catalyst was activated prior to the reaction at 200° C. and 170 bar over a period of 18 h in a 50:50 mixture of hydrogen and nitrogen.

(45) All catalysts were tested under the following conditions: Temperature: 165° C. Pressure: 170 bar H2: 5 L (STP)/h N2: 10 L (STP)/h Molar NH3:MEG ratio=10:1 Catalyst hourly space velocity: 0.3 kg/L/h-0.5 kg/L/h Catalyst volume: 50 mL

(46) The exact conditions are summarized in table 4 below

(47) TABLE-US-00004 TABLE 4 NMEDA + NEEDA + Tot. sel. (5 Cat. HSV/ Conversion/ EDA/ DETA/ AEEA/ PIP/ MEA/ EA/ main products)/ (EDA + DETA)/ Catalyst kg/L/h area % area % area % area % area % area % area % area % (PIP + AEEA) Comparative ex. 1 0.3 15.2 7.2 0.2 0.2 0.4 6.9 0.0 98.1 11.7 Comparative ex. 2 0.3 27.0 11.6 0.9 0.9 1.6 11.4 0.0 97.9 5.0 Comparative ex. 3 0.3 30.3 13.5 1.2 1.1 2.6 11.1 0.0 97.4 4.0 Example 1 0.3 46.6 20.1 2.3 2.2 5.7 11.7 2.5 90.2 2.9 Example 2 0.3 41.4 15.9 3.2 2.1 7.4 10.5 0.2 94.5 2.0

(48) In comparative example 1, a catalyst precursor (an alumina support material impregnated with Ru and Co) was oxidatively calcined.

(49) Example 1 differs from the comparative example in that the catalyst precursor was calcined not oxidatively, but reductively.

(50) It is found that the reductive calcination drastically increased the conversion. In spite of the high conversion, the selectivity quotient is 2.9, and so the reaction of the invention gave the desired EDA and DETA products to a high degree, and the unwanted PIP and AEEA products were obtained to a small degree. At the same time, only small amounts of unwanted by-products, such as NMEDA, are formed.

(51) In comparative example 2, a the catalyst precursor comprising Ni, Co, Cu and Sn on alumina, after drying, was oxidatively calcined in the presence of air at 450° C.

(52) In comparative example 3, a the oxidatively calcined catalyst precursor from comparative example 2 was post-impregnated with Ru and Co, and the impregnated catalyst precursor thus obtained was oxidatively calcined.

(53) Example 2 differs from example 3 in that the catalyst precursor impregnated with Ru and Co was reductively calcined.

(54) It is found that the reductive calcination drastically increased the conversion. In spite of the high conversion, the selectivity quotient is 2.0, and so the reaction of the invention gave the desired EDA and DETA products to a high degree, and the unwanted PIP and AEEA products were obtained to a small degree. At the same time, only small amounts of unwanted by-products, such as NMEDA, are formed.

(55) A comparison of example 1 and example 2 shows that, in the case of catalyst precursors that are prepared by impregnating a catalytic support material (example 2) rather than a conventional support material (example 1) and then reductively calcined, it is possible to increase the selectivity once again. At the same time, it is possible to lower the amount of unwanted by-products, such as NMEDA.