Low temperature pyrolysis method for low-rank coal with small particle size

Abstract

The invention relates to a low temperature pyrolysis method for low-rank coal with small particle size. The low temperature pyrolysis method comprises the following steps: adding raw coal into a drying tower from a warehouse by virtue of an elevator, and carrying out preheating and drying; putting the dried raw coal into a buffer coal bin to be stored by virtue of the elevator, and continuously feeding into a distributed high-thermal-conductivity pyrolysis device to realize low temperature pyrolysis (at the temperature of 500-650 DEG C); after pyrolysis, feeding high-temperature coke powder into a coke quenching device, cooling by virtue of coke quenching steam and coke quenching water, and then discharging out under the control of a discharging valve; realizing oil-dust separation on raw coal gas produced during pyrolysis by carrying out dynamic material layer and high temperature secondary dust removal; directly spraying circulating ammonia water to the raw coal gas after the dust removal in a cooling tower for cooling, primarily separating coal tar in the raw coal gas, and then carrying out secondary tar removal on the coal gas by virtue of an electrical tar precipitator; and sending out the purified coal gas by virtue of an induced draft fan to be returned back to a furnace or taken as fuel gas. The low temperature pyrolysis method provided by the invention can solve the problem of realizing oil-dust separation during low temperature pyrolysis and phyrolysis by utilizing coal with the small particle size and has the advantages of high fine powder removal rate, high environmental protection performance and high pyrolysis efficiency.

Description

technical field [0001] The invention relates to the technical field of coal chemical industry, in particular to a low-temperature pyrolysis method for low-rank coal with a small particle size (0-30mm). Background technique [0002] my country is rich in low-rank coal resources and has huge reserves. With the improvement of fully mechanized mining rate, the proportion of small particle size coal is getting heavier and heavier. Low-rank coal can be pyrolyzed to obtain clean oil products, chemicals, synthetic natural gas and other high value-added products, which is the main technical path for comprehensive utilization of coal. However, due to the difficulty of separating the mixture of fine coal and coal tar, and the easy blockage of equipment and pipelines, the engineering problems of pulverized coal pyrolysis have not been effectively broken through. In the initial stage, there is no mature industrial application performance yet, and there are still many engineering problem...

AI Technical Summary

Problems solved by technology

However, due to the difficulty of separating the mixture of fine coal and coal tar, and the easy blockage of equipment and pipelines, the engineering problems of pulverized coal pyrolysis have not been effectively broken through. In the initial stage, there is no mature industrial application performance, and there are still many engineering problems to be solved

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