Method and device for utilizing high value through pyrolysis and gasification of coal

Abstract

The invention relates to a method and a device for utilizing high value through pyrolysis and gasification of coal. The pyrolysis and gasification processes of the coal are separated in a mode of coupling a dilute phase conveying bed and a dense phase fluidized bed; and the coal is partially or wholly pyrolyzed before gasification, and co-production of pyrolysis gas, gasification generated gas and pyrolysis oil is realized. The dilute phase conveying bed and the dense phase fluidized bed can be coupled in two modes, namely upper-lower coupling and left-right coupling, and are applied to treating the coal in wide particle diameter distribution. High-value organic structures in the coal can be extracted before the gasification of the coal, and the utilization value of the coal is improved.

Description

technical field [0001] The invention belongs to the technical field of high-value comprehensive utilization of coal and energy quality improvement and high-efficiency, high-clean energy, and relates to a method and a device suitable for high-value utilization of pyrolysis gasification of coal with wide particle size. Background technique [0002] my country is poor in oil and natural gas resources, but relatively rich in coal resources. In my country's primary energy consumption structure, coal consumption accounts for about 68.7% of the total energy consumption structure. The existing coal utilization methods are mainly combustion, gasification, liquefaction and pyrolysis, among which combustion is the main utilization mode of coal, and its coal consumption accounts for about 80% of the total coal consumption. Coal contains a large amount of C and H chemical structure resources. On the one hand, direct combustion has low utilization efficiency and serious pollution. On the...

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Problems solved by technology

The "circulating fluidized bed thermoelectricity tar polygeneration device and its method" (CN 1978591A) proposed by Zhejiang University combines a fluidized bed retort furnace and a circulating fluidized bed combustion furnace, and utilizes the circulating hot ash of the circulating fluidized bed to achieve The pyrolysis of coal produces pyrolysis oil, pyrolysis gas and semi-coke, and the produced semi-coke is transported to the circulating fluidized bed combustion furnace for combustion to heat water and generate electricity, although this method can extract pyrolysis by pyrolysis oil, but a large amount of semi-coke is burned, and the C and H structure resources in coal cannot be fully utilized

The "circulating fluidized bed boiler high-temperature ash pyrolysis coal-to-oil device" (CN 200996006Y) proposed by Shandong University sends part of the high-temperature circulating ash into the pyrolysis reactor to be mixed with coal by setting a spiral ash collector under the cyclone separator. The powder is mixed and pyrolyzed, and the mixture of semi-coke and circulating ash produced by pyrolysis is transported by the screw conveyor under the pyrolysis reactor to the circulating fluidized bed boiler for combustion. This technology uses baffles in the pyrolysis reactor To realize the mixing of coal ash and coal powder, it is difficult to ensure the uniform mixing of coal ash and coal powder, and the screw used for ash collection must be able to withstand high temperature, which makes it difficult to scale up and run the technology for a long time

[0005] In short, the existing high-value comprehensive utilization technologies of coal mainly combine pyrolysis and combustion of coal, and most of them are aimed at pulverized coal, and the processing consumption of coal is relatively high

In the process of raw coal production and grading preparation of granular coal, a large amount of crushed coal with a wide particle size distribution below 25mm will be produced. Most of these coals are used for boiler combustion, and it is difficult to obtain high-value and efficient utilization.

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