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CN-224207419-U - Five tower multiple effect rectifier unit of crude methyl alcohol

CN224207419UCN 224207419 UCN224207419 UCN 224207419UCN-224207419-U

Abstract

The application provides a crude methanol five-tower multi-effect rectifying device which comprises a pre-rectifying tower, a negative pressure rectifying tower, an atmospheric rectifying tower, a low-pressure rectifying tower and a high-pressure rectifying tower, wherein a pre-tower reboiler I and a pre-tower reboiler II are arranged at the lower part of the pre-rectifying tower, a negative pressure tower reboiler I and a negative pressure tower reboiler II are arranged at the lower part of the negative pressure rectifying tower, an atmospheric rectifying tower reboiler, a low-pressure rectifying tower and a high-pressure rectifying tower are respectively arranged at the lower parts of the atmospheric rectifying tower, the low-pressure rectifying tower and the high-pressure rectifying tower, the heat of the top of the pre-rectifying tower is used for supplying heat to the negative pressure tower reboiler I, the heat of the top of the atmospheric rectifying tower is used for supplying heat to the atmospheric rectifying tower reboiler II, the heat of the pre-rectifying tower reboiler II, the steam unit consumption can be reduced to 0.52-0.54 t of steam/t of rectifying methanol, and the highest steam unit consumption is 0.54t of steam/t of rectifying methanol, and the steam unit consumption is reduced.

Inventors

  • ZHANG BING
  • WANG YAQI
  • ZHANG CHUNLU
  • ZHOU CHUNCHENG
  • HE JIAQI

Assignees

  • 天津卡碳兴业科技有限公司
  • 天津和碳兴华科技有限公司

Dates

Publication Date
20260508
Application Date
20250430

Claims (10)

  1. 1. The five-tower multi-effect rectifying device for crude methanol is characterized by comprising a pre-rectifying tower (1), a negative pressure rectifying tower (2), a normal pressure rectifying tower (3), a low pressure rectifying tower (4) and a high pressure rectifying tower (5) which are sequentially connected, wherein the lower part of the pre-rectifying tower (1) is provided with a pre-tower reboiler I (25) and a pre-tower reboiler II (26), the lower part of the negative pressure rectifying tower (2) is provided with a negative pressure tower reboiler I (27) and a negative pressure tower reboiler II (28), the lower parts of the normal pressure rectifying tower (3), the low pressure rectifying tower (4) and the high pressure rectifying tower (5) are respectively provided with a normal pressure tower reboiler (29), a low pressure tower reboiler (30) and a high pressure rectifying tower reboiler (31), the heat of the pre-rectifying tower (1) is used for supplying heat to the negative pressure tower reboiler I (27), the heat of the low pressure rectifying tower (3) is used for supplying heat to the negative pressure tower reboiler II (28), and the heat of the low pressure rectifying tower (4) is used for supplying heat to the normal pressure tower reboiler II (29) and the high pressure rectifying tower (5).
  2. 2. The five-tower multi-effect rectifying device for crude methanol according to claim 1, wherein the tower top of the pre-rectifying tower (1) is connected with a negative pressure tower reboiler I (27) through a pre-tower top extraction pipeline (32), the tower top of the normal pressure rectifying tower (3) is connected with a negative pressure tower reboiler II (28) through a normal pressure tower top extraction pipeline (33), the tower top of the low pressure rectifying tower (4) is connected with a pre-tower reboiler II (26) and a normal pressure tower reboiler (29) through a low pressure tower top extraction pipeline (34), and the top of the high pressure rectifying tower (5) is connected with a low pressure tower reboiler (30) through a high pressure tower top extraction pipeline (35).
  3. 3. The five-tower multi-effect rectifying device for crude methanol according to claim 2, wherein the output end of the pre-tower reboiler II (26) and the output end of the normal pressure tower reboiler (29) are respectively connected with a low pressure tower reflux tank (41), the bottom of the low pressure tower reflux tank (41) is connected with the low pressure rectifying tower (4) through a low pressure tower reflux pipeline (42), and the low pressure tower reflux pipeline (42) is connected with a low pressure tower refined methanol extraction pipeline (43).
  4. 4. The five-tower multi-effect rectifying device for crude methanol according to claim 2, wherein the output end of the negative pressure tower reboiler I (27) is connected with a pre-tower reflux tank (46), the bottom of the pre-tower reflux tank (46) is connected with a pre-rectifying tower (1) through a pre-tower reflux pipeline (47), the top of the pre-tower reflux tank (46) is connected with an extraction tower (50) through a gas phase extraction pipeline (49), a pre-tower tail cooler (51) is arranged on the gas phase extraction pipeline (49), the top of the extraction tower (50) is connected with a non-condensable gas extraction pipeline (52), one side of the extraction tower (50) is connected with an extraction water pipeline (53), and one side of the extraction tower (50) is connected with a miscellaneous oil extraction pipeline (54).
  5. 5. The five-tower multi-effect rectifying device for crude methanol according to claim 2, wherein the output end of the negative pressure tower reboiler II (28) is connected with an atmospheric tower reflux tank (56), the bottom of the atmospheric tower reflux tank (56) is connected with an atmospheric rectifying tower (3) through an atmospheric tower reflux pipeline (57), and the atmospheric tower reflux pipeline (57) is connected with an atmospheric tower refined methanol extraction pipeline (59).
  6. 6. The five-tower multi-effect rectifying device for crude methanol according to claim 2, wherein the output end of the low-pressure tower reboiler (30) is connected with a high-pressure tower reflux tank (61), the bottom of the high-pressure tower reflux tank (61) is connected with the high-pressure rectifying tower (5) through a high-pressure tower reflux pipeline (62), and the high-pressure tower reflux pipeline (62) is connected with a high-pressure tower refined methanol extraction pipeline (64).
  7. 7. The five-tower multi-effect rectifying device for crude methanol is characterized in that the top of the negative pressure rectifying tower (2) is connected with a negative pressure tower reflux drum (66) through a negative pressure tower top extraction pipeline (65), a negative pressure tower condenser (67) is arranged on the negative pressure tower top extraction pipeline (65), the bottom of the negative pressure tower reflux drum (66) is connected with the negative pressure rectifying tower (2) through a negative pressure tower reflux pipeline (68), the negative pressure tower reflux pipeline (68) is connected with a negative pressure tower refined methanol extraction pipeline (70), the negative pressure tower reflux drum (66) is connected with a buffer drum (72) through a reflux drum gas phase extraction pipeline (71), a negative pressure tower tail cooler (73) is arranged on the reflux drum gas phase extraction pipeline (71), the bottom of the buffer drum (72) is connected with the negative pressure tower reflux drum (66) through a buffer drum bottom pipeline (74), and the top of the buffer drum (72) is connected with a vacuum pipeline (75).
  8. 8. The five-tower multi-effect rectifying device for crude methanol according to claim 1, wherein one side of the pre-rectifying tower (1) is connected with a feeding pipeline (6), and a first pre-tower preheater (7) and a second pre-tower preheater (8) are arranged on the feeding pipeline (6) in parallel.
  9. 9. The five-tower multi-effect rectifying device for crude methanol according to claim 8, wherein a waste water pipeline (22) is connected to a tower kettle of the high-pressure rectifying tower (5), the waste water pipeline (22) passes through a pre-tower preheater II (8), and a waste water cooler (24) is arranged on the waste water pipeline (22) at the output end of the pre-tower preheater II (8).
  10. 10. A five-column multi-effect rectifying unit for crude methanol according to any one of claims 3, 5 and 6, characterized in that the heat is supplied to the pre-column preheater one (7) by the refined methanol extracted from the normal pressure column refined methanol extraction line (59), the low pressure column refined methanol extraction line (43) and the high pressure column refined methanol extraction line (64).

Description

Five tower multiple effect rectifier unit of crude methyl alcohol Technical Field The application relates to the technical field of chemical industry, in particular to a five-tower multi-effect rectifying device for crude methanol. Background In the production process of methanol, rectification is a key separation operation for purifying methanol products, the traditional methanol rectification generally adopts a pre-tower, an atmospheric tower and an atmospheric tower three-tower process, and utilizes the steam at the top of the atmospheric tower as heating coupling of the atmospheric tower to realize the purpose of energy saving, however, the atmospheric tower and the top of the pre-tower utilize circulating water for cooling, so that a large amount of heat is wasted, and the steam unit consumption of the whole system is high, namely about 1.2t of steam/t of refined methanol. Under the background that the national requirements on carbon emission indexes are stricter and stricter, a new technology is needed to recover heat in an original system so as to achieve the aim of energy conservation and emission reduction, therefore, five-tower three-effect, five-tower four-effect, five-tower multi-effect and other energy conservation devices are generated accordingly, a technical scheme is disclosed in a crude methanol five-tower thermal coupling refining device with the application number of 202421477006.3, the technical scheme comprises a prefractionation tower, an atmospheric pressure rectification tower, a medium pressure rectification tower, a first pressurizing rectification tower and a second pressurizing rectification tower which are sequentially connected, wherein the top of the prefractionation tower is connected with the first pressurizing tower reboiler, the top of the medium pressure rectification tower is connected with the first pressurizing tower reboiler and the second pressurizing tower reboiler, the top of the second pressurizing rectification tower is connected with the second pressurizing tower reboiler through a top extraction pipeline, the top steam of the first pressurizing rectification tower provides heat for the medium pressure rectification tower and the second pressurizing rectification tower, the middle pressure rectification tower steam provides heat for the prefractionation tower, the top of the prefractionation tower and the second pressurizing rectification tower is connected with the second pressurizing rectification tower reboiler, and the heat of the first pressurizing rectification tower and the second pressurizing rectification tower is fully consumed by the methanol to the pressure of 0.60 per-50, and the consumption of the methanol can be reduced by the single distillation tower per 60 per unit of the whole distillation tower. The steam unit consumption of the methanol rectification process in the application is greatly reduced compared with the prior art, but the maximum 0.60t steam/t refined alcohol is still relatively high, and the space can be reduced. In view of the foregoing, a new technical solution is needed to solve the above technical problems. Disclosure of utility model The application provides a crude methanol five-tower multi-effect rectifying device which comprises a pre-rectifying tower, a negative pressure rectifying tower, an atmospheric rectifying tower, a low pressure rectifying tower and a high pressure rectifying tower which are sequentially connected, wherein a pre-tower reboiler I and a pre-tower reboiler II are arranged at the lower part of the pre-rectifying tower, a negative pressure tower reboiler I and a negative pressure tower reboiler II are arranged at the lower part of the negative pressure rectifying tower, an atmospheric rectifying tower reboiler, a low pressure rectifying tower reboiler and a high pressure rectifying tower are respectively arranged at the lower parts of the atmospheric rectifying tower, the low pressure rectifying tower and the high pressure rectifying tower, the heat at the top of the pre-rectifying tower is used for supplying heat to the negative pressure tower reboiler I, the heat at the top of the atmospheric rectifying tower is used for supplying heat to the negative pressure tower reboiler II, the heat at the top of the low pressure rectifying tower is used for supplying heat to the atmospheric rectifying tower reboiler and the pre-rectifying tower reboiler II, and the heat at the top of the high pressure rectifying tower is used for supplying heat to the low pressure rectifying tower reboiler I. As a preferable scheme, the top of the pre-rectifying tower is connected with a first negative pressure tower reboiler through a pre-tower top extraction pipeline, the top of the normal pressure rectifying tower is connected with a second negative pressure tower reboiler through a normal pressure tower top extraction pipeline, the top of the low pressure rectifying tower is connected with the second pre-tower reboiler and