Gas-steam combined cycle system and technique based on coal gasification and methanation

Abstract

A combined cycle system based on coal gasification and methanation gas-steam and a technique thereof, wherein, the method comprises the following steps: oxygen produced by an air separation unit and coal powder or water-coal-slurry are sent into coal gasification equipment, the produced crude gasification gas is sent to a carbon monoxide sulfur-tolerant shift reactor to adjust the ratio of hydrogen and carbon after the sensible heat recollecting, and is then sent into sulfur-tolerant methanation reactor to produce methane and carbon dioxide, then the reaction product is sent into desulfurization and decarbonization equipment so that element sulfur can be recovered and carbon dioxide can be separated so as to obtain substitute natural gas with high content of methane, part of which is sent to the gas-steam combined cycle equipment while the other part is sent to a urban gas system. The enriched CO2 density of the system can reach 50 to 60 percent, technical probability is provided for reasonably realizing low-energy-consumption reduced exhaust of CO2, no change needs to be done with gas turbines, each chemical unit operates according to established rated condition and needs not to change load owing to power conditioning so as to improve the economy of the operation of power plants; compared with the prior art, the energy utilization efficiency of the whole system is improved so as to realize the efficient clean utilization of coal.

Description

technical field [0001] The present invention mainly relates to a novel CO 2 High-concentration enrichment method, electricity-substituting natural gas cogeneration system and process method, especially the gas-steam combined cycle system and process method based on coal gasification and methanation with coal as raw material. Background technique [0002] In recent years, due to the soaring price of fuel oil and natural gas worldwide, coupled with the obvious intensification of the impact of the greenhouse effect on climate and ecology. According to the resource situation of rich coal and little gas in my country, IGCC, as a new type of clean coal power generation technology, relies on its high power supply efficiency and potential CO 2 The advantages of emission reduction have once again stood on the stage of history. However, it still faces the following three problems: first, the economy of IGCC power plants, the cost of IGCC power plants is currently twice the cost of o...

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Problems solved by technology

However, it still faces the following three problems: first, the economy of IGCC power plants, the cost of IGCC power plants is currently twice the cost of ordinary coal-fired power plants; second, the variable load operation capacity of IGCC power plants; Retrofitting Technology of Value Coal Gas

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