Low-grade coal gas flow injection dense-phase quick dry distillation upgrading method and system

Abstract

The invention relates to a low-grade coal gas flow injection dense-phase quick dry distillation upgrading method and system. The system comprises a dehydration treatment system, a dry distillation upgrading system and a gas supply system for providing a heat source for the dehydration treatment system and dry distillation upgrading system. The method combines the low-grade coal dehydration treatment technique and the dry distillation upgrading technique to coproduce semicoke, tar and coal gas. The method has the characteristics of simple system technique, low equipment investment, small occupied area, no emission of dust and other pollutants in the whole process, environment friendliness, energy saving and high efficiency, is convenient to operate, implements clean conversion of low-grade coal, and satisfies the requirements for continuous large-scale production.

Description

technical field [0001] The invention relates to a low-rank coal quality upgrading process, in particular to a method and system for low-rank coal gas flow ejection dense-phase rapid carbonization and quality upgrading. Background technique [0002] Low-rank coal refers to coal with a relatively low degree of coalification, mainly including lignite and sub-bituminous coal. The global low-rank coal resources exceed 510 billion tons, accounting for 49.1% of the world's total coal resources. China is rich in low-rank coal resources, and the proven reserves of lignite have reached 130.3 billion tons, accounting for nearly 13% of the country's coal reserves. Due to the high moisture content, high ash content, easy weathering and spontaneous combustion of low-rank coal, and the difficulty of washing and storage, the development and utilization of low-rank coal are greatly restricted. How to better develop and utilize low-rank coal resources reasonably and alleviate the growing tens...

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Problems solved by technology

This method uses the flue gas after burning coal and pyrolysis gas as the heat medium for drying low-rank coal. Since the heated flue gas is in direct contact with the low-rank coal, it is particularly important to control the oxygen content in the hot flue gas. Spontaneous combustion, or even an explosion accident; since the temperature of the pyrolysis gas is relatively high between 360 and 420 °C, using recycled tar to cool and wash it will cause the light components with low boiling points in the tar to volatilize and mix into the pyrolysis gas , thus affecting the product quality of tar and pyrolysis gas; as a heat carrier, the pyrolysis gas, as a heat carrier, is in countercurrent contact with tar in the quenching tower. , explosion accidents are prone to occur when heating and heating up; when low-rank coal is pyrolyzed, pyrolysis gas is blown from the lower part of the pyrolysis furnace. This heating method has certain requirements on the particle size of low-rank coal. If the coal particle size is too small, When the pyrolysis gas is blown in, the resistance is large, and low-rank coal is easy to pulverize when it is heated and dried, resulting in an increase in power consumption when the pyrolysis gas is blown in; Affected by other factors, it is easy to cause uneven heating of low-rank coal

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