Carbon dioxide conversion system used in coal-to-methanol process and working method thereof

Abstract

The invention discloses a carbon dioxide conversion system used in a coal-to-methanol process and a working method thereof, belonging to the technical field of the coal chemical industry. The system comprises a coal preparation unit, a coal gasification unit, a water gas conversion unit, a synthesis gas cooling unit, a low-temperature methanol washing unit, a synthesis gas-to-methanol unit, a water treatment unit, a waste heat power generation unit, an electrolytic hydrogen production unit, a CO2-to-methanol unit, a methanol rectification unit, a hydrogen collection unit, an oxygen collectionunit, an air separation unit and a sulfur recovery unit. According to the invention, CO2 generated in the coal-to-methanol process is converted into a methanol product on site; in-situ conversion of CO2 is realized, and a conversion product is CO2; low-temperature waste heat of the coal gasification and synthesis gas cooling units is adopted for power generation, so electric energy is provided forelectrolytic hydrogen production; pure oxygen generated in the electrolytic hydrogen production process is used for the coal gasification unit; and methanol yield is high, CO2 emission is low, equipment investment and operation cost are reduced, energy in the process is effectively utilized, energy is saved, and good application prospects are achieved.

Description

technical field

[0001] The invention belongs to the technical field of coal chemical industry, and particularly relates to a carbon dioxide conversion system and a working method thereof in a coal-to-methanol process. Background technique

[0002] With the rapid development of methanol industry, CO in methanol production 2 Emissions are also increasing. In the coal-to-methanol process, the unit product CO 2 Emissions are 3.4 to 5.4 tons of CO 2 / ton of methanol. Under the same production scale, the carbon emission of coal-based methanol production is nearly 8 times higher than that of natural gas production. Carbon emissions from coal-to-methanol production accounted for 53.38%, carbon emissions from fuel combustion in thermal power boilers accounted for 36.25%, and carbon emissions from net purchased electricity consumption accounted for 10.36%. It can be seen that direct carbon emissions are the main CO 2 Emission source, CO 2 There is a lot of room for emission re...

Examples

Embodiment

[0039] The coal preparation unit 1 crushes, grinds or otherwise treats the raw coal according to the gasification process, and the coal input amount is 162.8t / h. O produced by electrolytic hydrogen production unit 9 2 Enter the oxygen collection unit 13 for collection, and then enter the coal gasification unit 2 together with the raw coal produced by the coal preparation unit 1 and the oxygen produced by the air separation unit 14 for coal gasification reaction, and adjust the oxygen to coal ratio (O / C) of the coal gasification unit 2 =1.01~1.05. Carbon in coal is partially oxidized to form H 2 , CO, CO 2 and H 2 O and others such as H 2 S, CH 4 The generated crude gas is sent to the water-gas shift unit 3 for water-gas shift reaction after washing, and the waste water generated during the washing process of the coal gasification unit 2 is sent to the water treatment unit 7, which adopts the flocculation reaction precipitation process to remove the suspension in the raw w...

technical field

[0001] The invention belongs to the technical field of coal chemical industry, and particularly relates to a carbon dioxide conversion system and a working method thereof in a coal-to-methanol process. Background technique

[0002] With the rapid development of methanol industry, CO in methanol production 2 Emissions are also increasing. In the coal-to-methanol process, the unit product CO 2 Emissions are 3.4 to 5.4 tons of CO 2 / ton of methanol. Under the same production scale, the carbon emission of coal-based methanol production is nearly 8 times higher than that of natural gas production. Carbon emissions from coal-to-methanol production accounted for 53.38%, carbon emissions from fuel combustion in thermal power boilers accounted for 36.25%, and carbon emissions from net purchased electricity consumption accounted for 10.36%. It can be seen that direct carbon emissions are the main CO 2 Emission source, CO 2 There is a lot of room for emission re...

Examples

Embodiment

[0039] The coal preparation unit 1 crushes, grinds or otherwise treats the raw coal according to the gasification process, and the coal input amount is 162.8t / h. O produced by electrolytic hydrogen production unit 9 2 Enter the oxygen collection unit 13 for collection, and then enter the coal gasification unit 2 together with the raw coal produced by the coal preparation unit 1 and the oxygen produced by the air separation unit 14 for coal gasification reaction, and adjust the oxygen to coal ratio (O / C) of the coal gasification unit 2 =1.01~1.05. Carbon in coal is partially oxidized to form H 2 , CO, CO 2 and H 2 O and others such as H 2 S, CH 4 The generated crude gas is sent to the water-gas shift unit 3 for water-gas shift reaction after washing, and the waste water generated during the washing process of the coal gasification unit 2 is sent to the water treatment unit 7, which adopts the flocculation reaction precipitation process to remove the suspension in the raw w...

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