Coal chemical poly-generation process and system

Abstract

The invention belongs to the field of coal chemical, and discloses a coal chemical poly-generation process and a coal chemical poly-generation system. According to the invention, coke and oxygen-rich gas obtained after low-rank coal upgrading conversion and quicklime are adopted as raw materials; calcium carbide is prepared by using an oxygen heat method; and acetylene is produced with a dry-method acetylene production process. Part of calcium carbide residue containing calcium hydroxide is outputted as a by-product, and another part of the calcium carbide residue containing calcium hydroxide is calcined and prepared into calcium oxide, which is then recycled as a calcium carbide preparation unit raw material. High-purity CO furnace gas produced by the calcium carbide preparation unit is added into the oxygen-rich gas, such that molten carbonate fuel cell raw material is prepared and electricity generation can be carried out. Further, heat contained in discharged gas of fuel cell recovered with a heat recovery technology and heat produced after combustion thereof are respectively used for providing heat for a steam Rankine cycle, a raw material preheating unit, a drying unit, and a calcining unit. Steam Rankine cycle condensed water is pump-pressurized; heat contained in fuel cell tail gas, combustion unit tail gas, calcining unit discharged water, and drying unit discharged water are recovered; and steam generation is carried out. With the process and the system provided by the invention, energy cascade utilization is realized.

Description

technical field [0001] The invention relates to coal chemical polygeneration technology, in particular to a method for cogeneration of electric power by low-rank coal-based oxythermal calcium carbide acetylene process. The technology of the invention uses low-rank coal-based oxythermal calcium carbide process and dry acetylene process to produce acetylene, and by-product calcium hydroxide calcium carbide slag, recovers the waste heat of calcium carbide furnace gas and uses fuel cell / steam combined cycle power generation. Fuel cells can directly use CO-rich carbide furnace gas as the fuel gas input for the anode. The technology of the invention can be used for recovery and utilization of CO-rich gas and process waste heat. Background technique [0002] Based on the efficient utilization of low-rank coal, the use of low-rank coal-based acetylene process route instead of petroleum ethylene process route is one of the effective solutions to alleviate the tight supply of petrole...

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Problems solved by technology

[0004] However, according to literature reports, the energy grade of CO is relatively high, and it should be considered to make full use of its chemical energy to prepare chemicals and fuel gas, and then use thermal energy to realize energy cascade utilization [Jin Hongguang, Comprehensive cascade utilization of energy and gas turbine total energy system, Science Press, 2008]

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