阅读说明：本技术 通过用溶剂/水混合物洗涤来回收丙烯 (Propylene recovery by washing with solvent/water mixtures ) 是由 N·T·沃兹 U·穆勒 A-N·帕乌莱斯库 D·里德尔 M·克兰普 D·乌尔班奇克 U· 于 2018-04-13 设计创作，主要内容包括：本发明涉及制备环氧丙烷的方法,其包括(i)提供包含丙烯、丙烷、过氧化氢或过氧化氢源、水和有机溶剂的物流；(ii)使(i)中提供的液体进料物流进入包括含钛沸石的环氧化催化剂的环氧化区,并使液体进料物流在环氧化区中经受环氧化反应条件,获得包含丙烯、丙烷、环氧丙烷、水和有机溶剂的反应混合物；(iii)从环氧化区移出流出物流,该流出物流包含丙烯、丙烷、环氧丙烷、水和有机溶剂；(iv)通过蒸馏从流出物流中分离出丙烯和丙烷,包括使流出物流在蒸馏装置中经受蒸馏条件,获得与经受蒸馏条件的流出物流相比富含丙烯和丙烷的气体物流(S1),和与经受蒸馏条件的流出物流相比富含环氧丙烷、水和有机溶剂的液体底部物流(S2)；(v)在分离区中,从物流(S1)中分离出丙烷,包括使物流(S1)在洗涤器中经受洗涤条件,其中添加包含有机溶剂和水的溶剂混合物作为夹带剂,获得底部物流(S3),其包含有机溶剂、水和至少70重量％的(S1)中所含的丙烯；和气体顶部物流(S4),其包含至少5重量％的物流(S1)中所含的丙烷。(The present invention relates to a process for the preparation of propylene oxide comprising (i) providing a stream comprising propylene, propane, hydrogen peroxide or a source thereof, water and an organic solvent; (ii) (ii) passing the liquid feedstream provided in (i) to an epoxidation zone comprising an epoxidation catalyst comprising a titanium-containing zeolite and subjecting the liquid feedstream to epoxidation reaction conditions in the epoxidation zone to obtain a reaction mixture comprising propene, propane, propene oxide, water and an organic solvent; (iii) removing from the epoxidation zone an effluent stream comprising propylene, propane, propylene oxide, water and organic solvent; (iv) separating propylene and propane from the effluent stream by distillation, comprising subjecting the effluent stream to distillation conditions in a distillation unit to obtain a gaseous stream enriched in propylene and propane compared to the effluent stream subjected to distillation conditions (S1), and a liquid bottoms stream enriched in propylene oxide, water and organic solvent compared to the effluent stream subjected to distillation conditions (S2); (v) separating propane from the stream (S1) in a separation zone comprising subjecting the stream (S1) to washing conditions in a washer, wherein a solvent mixture comprising an organic solvent and water is added as entrainer, obtaining a bottom stream (S3) comprising organic solvent, water and at least 70 wt% of the propylene contained in (S1); and a gaseous overhead stream (S4) comprising at least 5 wt% of the propane contained in stream (S1).)

1. A process for the preparation of propylene oxide comprising:

(i) providing a stream comprising propylene, propane, hydrogen peroxide or a source thereof, water and an organic solvent;

(ii) (ii) passing the liquid feedstream provided in (i) to an epoxidation zone comprising an epoxidation catalyst comprising a titanium-containing zeolite and subjecting the liquid feedstream to epoxidation reaction conditions in the epoxidation zone to obtain a reaction mixture comprising propene, propane, propene oxide, water and an organic solvent;

(iii) removing from the epoxidation zone an effluent stream comprising propylene, propane, propylene oxide, water and organic solvent;

(iv) separating propylene and propane from the effluent stream by distillation, comprising subjecting the effluent stream to distillation conditions in a distillation unit, obtaining a gaseous stream S1 enriched in propylene and propane compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream S2 enriched in propylene oxide, water and organic solvent compared to the effluent stream subjected to distillation conditions;

(v) separating propane from stream S1 in a separation zone comprising subjecting stream S1 to washing conditions in a washer wherein a solvent mixture comprising organic solvent and water is added as entrainer to obtain a bottom stream S3 comprising organic solvent, water and at least 70 wt% of the propylene contained in S1; and a gaseous overhead stream S4 comprising at least 5 wt% of the propane contained in stream S1.

2. The process according to claim 1, wherein the solvent mixture comprising organic solvent and water added as entrainer in (v) has a capacity KAP for propylene at 25 ℃ of from 0.01 to 0.2, preferably from 0.02 to 0.19.

3. The process of claim 1 or 2, wherein the solvent mixture comprising organic solvent and water added in (v) as entrainer has a mass-based capacity for propylene, KAP, at 25 ℃_mFrom 4.4 to 10, preferably from 4.5 to 9, more preferably from 4.6 to 8, more preferably from 4.7 to 7.

4. The process according to any one of claims 1 to 3, wherein the solvent mixture comprising an organic solvent and water added as entrainer in (v) has a selectivity S for propylene at 25 ℃ of from 1.3 to 3.5, preferably from 1.4 to 3.4, more preferably from 1.5 to 3.3.

5. The process according to any one of claims 1 to 4, wherein the organic solvent contained in the solvent mixture added as entrainer in (v) is the same organic solvent as contained in the stream provided in (i).

6. The process according to any one of claims 1 to 5, wherein the solvent mixture added as entrainer in (v) comprises at least 0.1 wt. -%, preferably at least 1 wt. -%, more preferably at least 5 wt. -%, more preferably at least 10 wt. -%, more preferably at least 15 wt. -% of water based on the total weight of the solvent mixture.

7. The method of any one of claims 1 to 6, comprising:

(i) providing a stream comprising propylene, propane, hydrogen peroxide or a source thereof, water and acetonitrile;

(ii) (ii) passing the liquid feedstream provided in (i) to an epoxidation zone comprising an epoxidation catalyst comprising a titanium-containing zeolite and subjecting the liquid feedstream to epoxidation reaction conditions in the epoxidation zone to obtain a reaction mixture comprising propene, propane, propene oxide, water and acetonitrile;

(iii) removing an effluent stream from the epoxidation zone comprising propylene, propane, propylene oxide, water, and acetonitrile;

(iv) separating propylene and propane from the effluent stream by distillation, comprising subjecting the effluent stream to distillation conditions in a distillation unit to obtain a gaseous stream S1 enriched in propylene and propane compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream S2 enriched in propylene oxide, water and acetonitrile compared to the effluent stream subjected to distillation conditions;

(v) separating propane from stream S1 in a separation zone comprising subjecting stream S1 to washing conditions in a washer wherein a solvent mixture comprising acetonitrile and water is added as entrainer to obtain a bottom stream S3 comprising acetonitrile, water and at least 70 wt% of the propylene contained in S1; and a gaseous overhead stream S4 comprising at least 5 wt% of the propane contained in stream S1.

8. The method of any one of claims 1 to 6, comprising:

(i) providing a stream comprising propylene, propane, hydrogen peroxide or a source thereof, water and methanol;

(ii) (ii) passing the liquid feedstream provided in (i) to an epoxidation zone comprising an epoxidation catalyst comprising a titanium-containing zeolite and subjecting the liquid feedstream to epoxidation reaction conditions in the epoxidation zone to obtain a reaction mixture comprising propene, propane, propene oxide, water and methanol;

(iii) removing from the epoxidation zone an effluent stream comprising propylene, propane, propylene oxide, water and methanol;

(iv) separating propylene and propane from the effluent stream by distillation, comprising subjecting the effluent stream to distillation conditions in a distillation unit to obtain a gaseous stream S1 enriched in propylene and propane compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream S2 enriched in propylene oxide, water and methanol compared to the effluent stream subjected to distillation conditions;

(v) separating propane from stream S1 in a separation zone comprising subjecting stream S1 to washing conditions in a washer wherein a solvent mixture comprising methanol and water is added as entrainer to obtain a bottom stream S3 comprising methanol, water and at least 70 wt% of the propylene contained in S1; and a gaseous overhead stream S4 comprising at least 5 wt% of the propane contained in stream S1.

9. The process according to any one of claims 1 to 8, wherein the scrubber used in (v) is a column, preferably having from 2 to 20, more preferably from 3 to 18, more preferably from 5 to 15 theoretical plates.

10. The process according to any one of claims 1 to 9, wherein the solvent mixture comprising organic solvent and water added as entrainer to the scrubber used in (v) is added at a theoretical plate above the feed plate of stream S1, preferably in the range of plates 1 to 10 from the top, more preferably in the range of plates 1 to 5, more preferably in the range of plates 1 to 3, more preferably at the top of the scrubber (plate 1); and wherein the weight ratio of the solvent mixture comprising organic solvent and water, preferably added hourly as entrainer to the scrubber used in (v), to the stream S1 fed hourly to the scrubber is from 1:10 to 10:1, more preferably from 1:1 to 10:1, more preferably from 2:1 to 5: 1.

11. The method according to any one of claims 1 to 10, wherein the scrubber is operated at a top temperature of from 10 ℃ to 30 ℃, preferably from 14 ℃ to 26 ℃, more preferably from 15 ℃ to 22 ℃; wherein the scrubber preferably used in (v) is operated at a sump temperature of from 20 ℃ to 65 ℃, more preferably from 25 ℃ to 60 ℃, more preferably from 27 ℃ to 50 ℃; and wherein the scrubber preferably used in (v) is operated at a sump pressure of 1 to 35 bar, more preferably 5 to 32 bar, more preferably 10 to 30 bar.

12. The process of any one of claims 1 to 11, wherein the separation zone in (v) comprises a distillation apparatus and a scrubber, wherein

(v.i) separating propane from the gaseous stream S1 by distillation in a distillation unit comprised in the separation zone, obtaining a gaseous stream S1a, preferably as top stream, enriched in propylene compared to stream S1 subjected to distillation conditions; the gaseous stream S1b, preferably as a side stream, is enriched in propylene compared to the stream S1 subjected to distillation conditions; and a bottom stream S1c, which contains almost no propylene compared to stream S1 subjected to distillation conditions; and

(v.ii) subjecting the gaseous stream S1a obtained in (v.i) to scrubbing conditions in a scrubber comprised in the separation zone, wherein a solvent mixture comprising organic solvent and water is added as entrainer, obtaining a bottom stream S3 comprising organic solvent, water and at least 70 wt% of the propylene comprised in S1; and a gaseous overhead stream S4 comprising at least 5 wt% of the propane contained in stream S1.

13. The method of any one of claims 1 to 12, comprising

(i) Providing a stream comprising propylene, propane, hydrogen peroxide or a source thereof, water and acetonitrile;

(ii) (ii) passing the liquid feedstream provided in (i) to an epoxidation zone comprising an epoxidation catalyst comprising a titanium-containing zeolite and subjecting the liquid feedstream to epoxidation reaction conditions in the epoxidation zone to obtain a reaction mixture comprising propene, propane, propene oxide, water and acetonitrile;

(iii) removing an effluent stream from the epoxidation zone comprising propylene, propane, propylene oxide, water, and acetonitrile;

(iv) separating propylene and propane from the effluent stream by distillation, comprising subjecting the effluent stream to distillation conditions in a distillation unit to obtain a gaseous stream S1 enriched in propylene and propane compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream S2 enriched in propylene oxide, water and acetonitrile compared to the effluent stream subjected to distillation conditions;

(v) separating propane from stream S1 in a separation zone, wherein the separation zone in (v) comprises a distillation apparatus and a scrubber, wherein

(v.i) separating propane from the gaseous stream S1 by distillation in a distillation unit comprised in the separation zone, obtaining a gaseous stream S1a, preferably as top stream, enriched in propylene compared to stream S1 subjected to distillation conditions; the gaseous stream S1b, preferably as a side stream, is enriched in propylene compared to the stream S1 subjected to distillation conditions; and a bottom stream S1c, which contains almost no propylene compared to stream S1 subjected to distillation conditions; and

(v.ii) subjecting the gaseous stream S1a obtained in (v.i) to scrubbing conditions in a scrubber comprised in the separation zone, wherein a solvent mixture comprising acetonitrile and water is added as entrainer, obtaining a bottom stream S3 comprising acetonitrile, water and at least 70 wt% of the propylene comprised in S1; and a gaseous overhead stream S4 which,

which comprises at least 5% by weight of the propane contained in stream S1.

14. The method of any one of claims 1 to 12, comprising

(i) Providing a stream comprising propylene, propane, hydrogen peroxide or a source thereof, water and methanol;

(ii) (ii) passing the liquid feedstream provided in (i) to an epoxidation zone comprising an epoxidation catalyst comprising a titanium-containing zeolite and subjecting the liquid feedstream to epoxidation reaction conditions in the epoxidation zone to obtain a reaction mixture comprising propene, propane, propene oxide, water and methanol;

(iii) removing from the epoxidation zone an effluent stream comprising propylene, propane, propylene oxide, water and methanol;

(iv) separating propylene and propane from the effluent stream by distillation, comprising subjecting the effluent stream to distillation conditions in a distillation unit to obtain a gaseous stream S1 enriched in propylene and propane compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream S2 enriched in propylene oxide, water and methanol compared to the effluent stream subjected to distillation conditions;

(v) separating propane from stream S1 in a separation zone, wherein the separation zone in (v) comprises a distillation apparatus and a scrubber, wherein

(v.i) separating propane from the gaseous stream S1 by distillation in a distillation unit comprised in the separation zone, obtaining a gaseous stream S1a, preferably as top stream, enriched in propylene compared to stream S1 subjected to distillation conditions; the gaseous stream S1b, preferably as a side stream, is enriched in propylene compared to the stream S1 subjected to distillation conditions; and a bottom stream S1c, which contains almost no propylene compared to stream S1 subjected to distillation conditions; and

(v.ii) subjecting the gaseous stream S1a obtained in (v.i) to scrubbing conditions in a scrubber comprised in the separation zone, wherein a solvent mixture comprising methanol and water is added as entrainer, obtaining a bottom stream S3 comprising methanol, water and at least 70 wt% of the propylene comprised in S1; and a gaseous overhead stream S4 which,

which comprises at least 5% by weight of the propane contained in stream S1.

15. The process of any one of claims 1 to 14, which is a continuous process.