Process for upgrading low-rank coal in an internally heating way with heated gas carrier

Abstract

The invention discloses a process for upgrading low-rank coal in an internally heating way with the heated gas carrier, comprising the following steps: (1) the crushed and screened raw coal is added to a rotating furnace grate arranged at the bottom of a reactor through a raw coal feeding elephant trunk; (2) hypoxic heated gas enters the reactor from a heating gas inlet arranged below the reactor to directly contact the raw coal sample and transfer heat to the raw coal sample through a hole chiseled on the rotating furnace grate, and the hypoxic heated gas and the raw coal sample are dried and subjected to the pyrolysis reaction; and (3) after a certain time of reaction, with the rotation of the rotating furnace grate, the processed raw coal sample is fixed on a plow-type mechanical stirrer which is arranged above the rotating furnace grate and is pushed to a discharge opening, and the tail gases of the heated gas are discharged out of a gas exhausting opening. The invention uses the hypoxic cyclic flue gas as the heat source to distill the low-rank coal and ensures that the hypoxic cyclic flue gas directly exchanges heat with the solid low-rank coal, thereby having high thermal efficiency and low energy consumption ratio. In addition, the invention has low requirement for the size of the granules of the processed low-rank coal and wide application range and can effectively reduce the content of the dust in the tail gases to be good for the transportation of the final product.

Description

technical field [0001] The invention relates to a technology for internal heat upgrading of low-rank coal by using an oxygen-depleted hot gas carrier. Background technique [0002] At present, the mining and utilization of my country's coal resources are still dominated by anthracite and bituminous coal. With the continuous increase in energy demand in my country and the resource shortage caused by over-exploitation of anthracite and bituminous coal resources, low-rank coal is replaced by upgrading and transforming High-rank coal is becoming more and more important to alleviate the pressure of energy demand. [0003] Low-rank coal includes peat, lignite, long-flame coal, gas coal, weakly caking coal and other sub-bituminous coal, accounting for about 50% of the world's coal resource reserves. More than 60% of the reserves. Mainly distributed in Yunnan, Inner Mongolia, Northeast China, Sichuan and other provinces. It is characterized by high water content, generally account...

AI Technical Summary

Problems solved by technology

Since the problem of high water content in real lignite cannot be solved, there are few mature industrialized technologies for lignite carbonization and upgrading, and most of them focus on the carbonization process of highly volatile, weakly bonded sub-bituminous coal

[0006] Chinese patent CN201053004Y introduces a process technology for dry distillation and upgrading of sub-bituminous coal and bituminous coal using a rotary furnace. Although this process has a large amount of coal to be processed, it can realize large-scale production, but the ability to process low-rank coal is not high, and energy consumption is large. Moreover, it has high requirements for factory construction, occupies a large area, and complex equipment supporting systems

[0007] Chinese patent CN1966612A discloses a technology for dry distillation and upgrading of weakly cohesive coal using a gas-carrier internal heating vertical furnace. This process can only be used for the upgrading of bituminous coal with low water content, and the coal type requires high requirements. , it is difficult to achieve the diversification of coal types; and in order to ensure the heat transfer efficiency and gas circulation volume of this process, the amount of coal processed is not large, and it is difficult to realize the expanded production on an industrial scale

[0008] Chinese patent CN1847364A discloses a process technology for thermal solid carrier pyrolysis using a circulating fluidized bed and a rotary kiln. Pyrolysis and dry distillation of rank coal, although the process is simple, the thermal efficiency is high, and a large yield of high calorific value gas and coal tar is obtained, but the production process is limited by the separation efficiency of gas powder, the gas and tar products have high dust content, and the problem of pipeline blockage It has not been completely solved, so the degree of industrialization is not high, and the production process has a great impact on the environment

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