Thermoelectricity combined production method and apparatus for preparing alkene and by coal and natural gas

Abstract

The invention relates to a thermoelectricity combined production method and apparatus for preparing alkene and by coal and natural gas, and the method comprises the following steps: (1) separating coal, steam and air for obtaining oxygen, gasifying oxygen for obtaining water gas by reaction, and purifying for obtaining coal-based synthetic gas; carrying out a reforming reaction from natural gas and carbon dioxide and obtaining a natural gas-based synthetic gas; (2) synthesizing methanol using the coal-based synthetic gas in the step (1) or using the coal-based synthetic gas and the natural gas-based synthetic gas; (3) separating the unreacted gas in the step (2) into three parts, and the first part is used for synthesizing methanol in the step (2), and the second part is used as fuel for providing heat for the natural gas reforming reaction, and the third part is used for power generation and heat supply for the gas turbine; (4) separating the methanol in the step (2) into two parts, and one part is used for preparing alkene and generating water; and the other part is used for the reforming reaction with the generated water for preparing hydrogen and carbon dioxide, and separating hydrogen and carbon dioxide, and synthesizing ammonia from the obtained hydrogen and nitrogen separated from air, wherein, the obtained carbon dioxide by separation is used for the natural gas reforming reaction.

Description

technical field [0001] The invention relates to a cogeneration method and device for producing olefins and ammonia from coal and natural gas. Background technique [0002] Ethylene and propylene are the most basic raw materials in the petrochemical industry. The output of ethylene is considered to be a sign of the level of national economic development. With the development of my country's economy and society, there will still be a relatively high rigid demand in the future. Traditional ethylene production methods mainly use ethane, propane, naphtha, and light diesel as raw materials to produce ethylene through steam cracking in tube furnaces. However, China's light hydrocarbon and petroleum resources are very limited and cannot meet the requirements of ethylene light raw materials. Moreover, the continuous rise of crude oil prices and the aggravation of the inferior quality of crude oil make the product cost of traditional ethylene production methods relatively high. In re...

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Problems solved by technology

[0004] In the method of producing ethylene from coal, since the hydrogen-to-carbon ratio in the synthesized gas is low, generally less than 1, gas shifting is often required when synthesizing downstream products to combine CO and H 2 O reacts to form H 2 and CO 2 Raise H 2 / CO, CO added during transformation 2 emissions to the environment, and in recovering CO 2 , CO removal 2 In the process of converting CO and CO, additional energy is consumed, which makes the energy utilization efficiency of the system lower

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