System and method for coal tar gas production by coupling of pulverized coal pyrolysis and dust removal

Abstract

The invention belongs to the technical field of clean and efficient utilization of coal, and particularly relates to a system and a method for preparing coal tar gas through powdered coal pyrolysis and dust removal coupling. The method mainly comprises the following steps: performing primary heat exchange drying and secondary heat exchange drying on powdered coal mainly by using circulating low-heat flue gas and cooling heat exchange flue gas in a sectional mode; performing grading and partitioned pyrolysis on large-particle and small-particle fine powder according to different pyrolysis residence periods of coals with different particle sizes, so as to promote pyrolysis of heavy-component products to generate light-component products; preliminarily filtering and dedusting raw coal gas subjected to the pyrolysis of the fine powder through a large-particle pyrolysis layer to realize fine dust removal, wherein the dedusted coke powder is cooled under the double effects of cooling gas andcooling water, thereby greatly improving the cooling efficiency. Meanwhile, coal tar, coal gas, semi-coke powder and other products prepared according to the method provided by the invention have high quality, can meet standard requirements, have high yields, and do not need regeneration of filter materials, the whole process is simplified, materials are recycled, the gas carrying capacity is small, neither waste residue nor waste gas is generated, heat energy is recycled, energy is saved and clean production is realized.

Description

technical field [0001] The invention belongs to the technical field of coal chemical industry, in particular to the technical field of clean and efficient utilization of coal, and particularly relates to a system and method for producing coal tar gas by coupling pulverized coal pyrolysis and dust removal. Background technique [0002] Pyrolysis of high volatile bituminous coal and lignite is an important way of coal cascade separation and utilization. It is a clean coal chemical industry. Coal pyrolysis is also called coal topping. It has low equipment investment, low energy consumption and high thermal efficiency. It has broad market prospects and comparative Good economic benefits. [0003] The pyrolysis process is different according to the coal particle size. The coal with the same particle size also has different pyrolysis processes. For the pyrolysis of 0-6mm pulverized coal, there are rotary kiln pyrolysis process, fluidized bed pyrolysis process, and Moving bed pyro...

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Problems solved by technology

[0008] The patent No. 201310316620.1 proposed by Elcometer Environmental Energy Research Institute Co., Ltd. and granted the invention patent right is a method for producing liquid fuel by rapid pyrolysis of solid organic matter. It is divided into two parts: one part is used as heat carrier for pyrolysis, and the other part is used as dust removal particles. This patent considers the fine dust removal of raw gas, and uses high-temperature heat carrier semi-coke as particle layer dust removal. Because high-temperature semi-coke has not been classified, and high temperature The temperature of the semi-coke as a particle layer is too high, and the coal tar will undergo secondary cracking when the raw gas passes through, which greatly reduces the yield of coal tar

At the same time, the residence time of pyrolysis was not changed for coal with different particle sizes.

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