Efficient electric energy storage and zero carbon emission technology for producing, storing and transporting dimethyl ether based on green hydrogen and coal gasification coupling

Abstract

The invention provides a high-efficiency electric energy storage and zero-carbon emission technology for producing, storing and transporting dimethyl ether based on coupling of green hydrogen and a coal gasification process. Green hydrogen is prepared from renewable energy electrolyzed water and coupled with the coal gasification process to generate synthesis gas, then methanol is synthesized, and dimethyl ether is generated through dehydration. Dimethyl ether is stored in a liquid form and transported in a long distance, and is transported in a gas form during short-distance transportation. Efficient electric energy storage and zero carbon emission are achieved, and high economic and environmental benefits are achieved.

Description

Technical Field

[0001] The present invention relates to an efficient electric energy storage and zero-carbon emission technology for the production, storage, and transportation of dimethyl ether by coupling green hydrogen with the coal gasification process, belonging to the fields of clean energy and chemical engineering technology. Background Art

[0002] With the increasing global demand for carbon emission reduction, green hydrogen, as a clean energy source, has broad application prospects. Green hydrogen is produced by using renewable energy such as wind and solar power to generate electricity and then electrolyzing water. Although traditional coal gasification technology is mature, it has the problem of high carbon emissions. The present invention aims to achieve low-carbon production of dimethyl ether by coupling green hydrogen with coal gasification, and at the same time provides an efficient electric energy storage solution. By converting electric energy into chemical energy and storing it in dimethyl ether, efficient electric energy storage and transportation are realized. Summary of the Invention

[0003] The present invention provides a method for producing dimethyl ether by coupling green hydrogen with coal gasification, comprising the following steps: 1. Using renewable energy to generate electricity, and then electrolyzing water with the generated electricity to prepare green hydrogen and oxygen. The specific reaction is: 2H2O = 2H2 + O 2。 The electrolytic water hydrogen production technology includes alkaline electrolytic water (AWE), proton exchange membrane electrolytic water (PEM), or solid oxide electrolytic water (SOEC), etc.; 2. Refining coal and mixing it with steam and oxygen for gasification to generate syngas. The specific reaction is: 3C + H2O + O2 = 3CO + H 2， The coal gasification adopts entrained flow gasification technology, with a gasification temperature of 1300 - 1500 °C and a gasification pressure of 20 - 50 bar; 3. Reacting syngas with the gas produced by electrolyzing water to synthesize methanol, and further dehydrating it to produce dimethyl ether to improve storage and transportation efficiency. The specific reactions are: 2H2 + CO = CH3OH, 2CH3OH = CH3OCH3 + H2O; 4. Compressing dimethyl ether into a liquid for storage and long-distance transportation, or transporting it to the user end in a gaseous form for short-distance transportation. When transporting over a long distance, dimethyl ether is compressed into a liquid; when transporting over a short distance, it is directly transported to the user end in a gaseous form.

[0004] The present invention realizes efficient electric energy storage and transportation by coupling green hydrogen production with coal gasification. The entire production process achieves zero carbon emissions. By using green hydrogen and optimizing coal gasification, the carbon emissions of traditional coal gasification are reduced. Specific Embodiment 1 (1) Green hydrogen preparation: Adopting alkaline electrolytic water hydrogen production technology, using solar or wind power to generate electricity for electrolyzing water to produce hydrogen.

[0006] 2H2O = 2H2 + O2 (2) Coal gasification: Using entrained flow gasification technology, the coal is refined and mixed with steam and oxygen. The gasification temperature is 1300 - 1500 °C, and the gasification pressure is 20 - 50 bar.

[0007] 3C + H2O + O2 = 3CO + H2 (3) Dimethyl ether synthesis and storage: Methanol is synthesized from syngas and then dehydrated to produce dimethyl ether. Dimethyl ether is stored in liquid form and transported over long distances, and transported in gas form for short - distance delivery.

[0008] 2H2 + CO = CH3OH, 2CH3OH = CH3OCH3 + H2O Specific Example 2

[0009] (1) Green hydrogen production: Using proton exchange membrane electrolysis of water (PEM) hydrogen production technology, hydrogen is produced by electrolyzing water using solar or wind power generation.

[0010] 2H2O = 2H2 + O2 (2) Coal gasification: Using entrained flow gasification technology, the coal is refined and mixed with steam and oxygen. The gasification temperature is 1300 - 1500 °C, and the gasification pressure is 20 - 50 bar.

[0011] 3C + H2O + O2 = 3CO + H2 (3) Dimethyl ether synthesis and storage: Methanol is synthesized from syngas and then dehydrated to produce dimethyl ether. Dimethyl ether is stored in liquid form and transported over long distances, and transported in gas form for short - distance delivery.

[0012] 2H2 + CO = CH3OH, 2CH3OH = CH3OCH3 + H2O Specific Example 3

[0013] (1) Green hydrogen production: Using solid oxide electrolysis of water (SOEC) hydrogen production technology, hydrogen is produced by electrolyzing water using solar or wind power generation.

[0014] 2H2O = 2H2 + O2 (2) Coal gasification: Using entrained flow gasification technology, the coal is refined and mixed with steam and oxygen. The gasification temperature is 1300 - 1500 °C, and the gasification pressure is 20 - 50 bar.

[0015] 3C + H2O + O2 = 3CO + H2 (3) Dimethyl ether synthesis and storage: Methanol is synthesized from syngas and then dehydrated to produce dimethyl ether. Dimethyl ether is stored in liquid form and transported over long distances, and transported in gas form for short - distance delivery.

[0016] 2H2 + CO = CH3OH, 2CH3OH = CH3OCH3 + H2O

Claims

1. A method for producing, storing and transporting dimethyl ether by coupling green hydrogen with coal gasification, characterized in that It includes the following steps: (1) Electrolyze water using electricity generated from renewable energy to produce green hydrogen and oxygen; (2) Crush and refine coal and mix it with steam and oxygen for gasification to produce syngas; (3) React syngas with the gas generated in step (1) to synthesize methanol and further dehydrate it to produce dimethyl ether; (4) Compress dimethyl ether into a liquid for storage and long-distance transportation, especially long-distance pipeline transportation, or transport it to the user end in the form of gas through a short-distance pipeline.

2. The method according to claim 1, characterized in that, The hydrogen production technology by electrolyzing water includes alkaline water electrolysis (AWE), proton exchange membrane water electrolysis (PEM), or solid oxide electrolysis cell (SOEC). The specific reaction is: 2H2O = 2H2 + O2.

3. The method according to claim 1, characterized in that, The coal gasification adopts entrained flow gasification technology. The gasification temperature is 1300 - 1500 °C, and the gasification pressure is 20 - 50 bar. The specific reaction is: 3C + H2O + O2 = 3CO + H2.

4. The method according to claim 1, characterized in that, The hydrogen production process by electrolyzing water is coupled with the coal gasification process. React the hydrogen in claim 2 with the carbon monoxide and hydrogen in claim 3 to produce methanol. All carbon enters the product, achieving zero carbon emissions. The specific reaction is: 2H2 + CO = CH3OH. In addition, dehydrate methanol to produce dimethyl ether, 2CH3OH = CH3OCH3 + H2O, and convert electrical energy into chemical energy and store it in dimethyl ether.

5. The method according to claim 1, wherein The storage and transportation methods of dimethyl ether include: • When transporting over a long distance, compress dimethyl ether into a liquid; when transporting over a short distance, directly transport it to the user end in the form of gas.

6. The method according to claim 1, wherein The entire production process achieves zero carbon emissions. By using green hydrogen and optimizing coal gasification, the carbon emissions of traditional coal gasification are reduced.