Method for preparing tar, coal gas and semi-coke by virtue of pyrolysis of bituminous coal

Abstract

The invention discloses a method for preparing tar, coal gas and semi-coke by virtue of pyrolysis of low-rank coal. The method comprises the following steps of processing pulverized raw material coal as in a three-stage manner, namely, a screening drying stage as the first stage, a low-temperature pyrolysis stage as the second stage and a medium-temperature pyrolysis stage as the third stage, wherein in the first stage, most moisture in the raw material coal is removed, the pulverized coal having the size of below 1mm is screened by wind power and used as a combustion raw material of a three-waste furnace for providing a heat source for a system, dust having the size of below 50 microns in the system is almost removed so that the pre-dust removal effect is achieved and the content of the dust in the end product coal tar is greatly reduced; during the second stage, the reaction temperature is controlled to be about 550-570 DEG C, and thus the highest tar yield is ensured; during the third stage, the reaction temperature is controlled to be about 690-710 DEG C the yield of the coal gas is increased. The products have the advantages of good quality, high yield, energy conservation and environment friendliness and the method has good economic and social benefits and is worthy in popularization and application.

Description

technical field [0001] The invention belongs to the field of coal chemical industry, and relates to a coal pyrolysis upgrading method, in particular to a method for preparing semi-coke, tar and gas by pyrolysis of low-rank coal. Background technique [0002] Low-metamorphic bituminous coal has the characteristics of high moisture, high volatile matter, and low calorific value. It has abundant reserves, but its thermal efficiency of direct combustion for power generation is low. How to efficiently utilize low-rank coal resources has gradually become the focus of development and research. Pyrolysis (dry distillation) technology is a commonly used coal processing technology. Since the last century, experts and scholars at home and abroad have developed various processes for coal pyrolysis technology. [0003] The main representative of foreign vertical internal heat retort furnace is the Lurgi-Spierges (L-S) low temperature retort furnace, which was developed by Lurqi GmbH in G...

AI Technical Summary

Problems solved by technology

However, the technological process is complicated, and there are many stages. During the operation, it is necessary to take into account the set temperature, pressure, fluidization state and semi-coke discharge of each stage of the fluidized pyrolysis furnace, which makes the control difficult.

Due to the large amount of dust entrained in the fluidized bed gas, the follow-up system is easy to block, and the tar contains a lot of fine-grained semi-coke, which needs to be removed

[0005] The purpose of the present invention is to provide a coal pyrolysis upgrading method to solve the problems of low heat utilization rate, low oil and gas yield, and large amount of dust in the prior art.

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