Fluidized bed hierarchical coal pyrolysis reactor and coal pyrolysis method

Abstract

The invention discloses a fluidized bed hierarchical coal pyrolysis reactor. The fluidized bed hierarchical coal pyrolysis reactor comprises a pyrolysis chamber, a separating wall, a pyrolytic gas waste heat recovery device, a coal conveying device, a large granule outlet, a mixed material outlet and an ash conveying device, wherein the pyrolysis chamber comprises a low-temperature pyrolysis chamber and a high-temperature pyrolysis chamber. The invention further discloses a method for performing coal pyrolysis by using the device. By the method, the yield of gas is high, the yield of tar is low, high-efficiency and complete pyrolysis of coal is realized, the gas flow is less fluidized, and excellent fluidized heat exchange and conveying of coal, semicoke and circulating ash are realized, so that energy consumption and heat loss caused by fluidized gas are reduced. Low-temperature pyrolytic gas and high-temperature pyrolytic gas are mixed, so secondary pyrolysis of the lightweight tar of the low-temperature pyrolytic gas is realized, the yield of the pyrolytic gas is increased and the amount of the tar is reduced; and the temperature of the medium-temperature gas after mixing is reduced compared with the pyrolysis final temperature of the coal pyrolysis reactor, so the capacity and the flowing resistance of the pyrolytic gas waste heat recovery device can be reduced, the cost of equipment materials is reduced and the reliability of the equipment is improved.

Description

technical field [0001] The invention relates to the technical field of coal pyrolysis, in particular to a fluidized bed graded coal pyrolysis reactor and a coal pyrolysis method. Background technique [0002] The current coal pyrolysis technology has a variety of application purposes, so different pyrolysis processes are also used. Some pyrolysis is to use the heat of coal combustion to separate the volatile components in coal, just to directly obtain coke or semi-coke; compared with coal and coke, most of the volatile components in coal have higher utilization value. The pyrolysis process based on coal-based energy and chemical industry is mainly for the production of tar and hydrogenated fuel oil. Usually, the pyrolysis gas generated by pyrolysis is directly burned to meet the needs of pyrolysis. This process is mainly used in the field of low-quality coal utilization. The application is more extensive. The polygeneration pyrolysis process, which mainly uses combustion p...

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Problems solved by technology

However, the pyrolysis gas from direct high-temperature pyrolysis of coal contains less methane and more hydrogen. This kind of pyrolysis gas is not conducive to the operation of gas turbine units in economical and safe conditions.

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