Integrated coal gasification combined power generation process with zero carbon emission

Abstract

The present disclosure relates to the technical field of coal chemical industry, and particularly discloses an integrated coal gasification combined power generation process with zero carbon emission, the process comprising: pressurizing air for performing air separation to obtain liquid oxygen and liquid nitrogen, wherein the liquid oxygen is used for gasification and power generation, the liquid nitrogen is applied as the coolant for the gasification and power generation, the liquid nitrogen and a part of liquid oxygen stored during the valley period with low electricity load are provided for use during the peak period with high electricity load; the pulverized coal delivered under pressure and high-pressure oxygen enter a coal gasification furnace for gasification, so as to generate high-temperature fuel gas, which subjects to heat exchange and purification, and then the high-pressure fuel gas enters into a combustion gas turbine along with oxygen and recyclable COfor burning and driving an air compressor and a generator to rotate at a high speed; the air compressor compresses the air to a pressure of 0.4˜0.8 MPa, and the generator generates electricity; the high-temperature combustion flue gas performs the supercritical COpower generation, its coolant is liquid oxygen or liquid nitrogen; the heat exchanged combustion fuel gas subsequently perform heat exchange with liquid nitrogen, the liquid nitrogen vaporizes to drive a nitrogen turbine generator for generating electricity, the cooled flue gas is dehydrated and distilled to separate CO, a part of COis used for circulation and temperature control, and another portion of COis sold outward as liquid COproduct. The power generation process provided by the present disclosure not only solves the difficult problems of high water consumption, low power generation efficiency and small range of peak load adjustment capacity of the existing IGCC technology; but also can compress air with high unit volume for energy storage with a high conversion efficiency, and greatly reduce load of the air compressor, thereby perform COcapture and utilization with low-cost, zero NOemission and discharging fuel gas at a normal temperature, and significantly improve the power generation efficiency.