Brown coal low temperature carbonization method

Abstract

The invention discloses a brown coal low temperature carbonization method. The method comprises the following steps of: by a gas heat carrier, firstly, heating the coal under the condition of isolating air, removing more than 90% of total moisture, crystal water and partial oxygen-containing functional groups which have influence on the coal heat value, and enriching the coal heating constituents; and further heating the coal to form solid semicoke, purifying the separated volatile constituent substance to recycle coal tar and coal gas products, recycling the afterheat of the high temperature semicoke and cooling the semicoke to collect the semicoke. The obtained semicoke has the advantages of high heat value, excellent stability and non-reabsorption and the like. The method is simple in technology, low in energy consumption, pollution-free and high in product quality, capable of realizing industrial large-scale production, and easy to generalize widely.

Description

technical field [0001] The invention belongs to the technical field of lignite dry distillation, and in particular relates to a low-temperature dry distillation method of lignite. Background technique [0002] Lignite is the coal with the lowest degree of coalification. It has high moisture content, up to 30%-60%; high oxygen content, up to 18-25%; low fixed carbon content, low calorific value, generally about 3000kca1 / kg; easily weathered and broken. Due to the poor quality of coal and the difficulty of economical long-distance transportation, the industrial application of lignite is mainly based on coal production areas. However, most of the main lignite production areas in my country are far away from cities and large industrial users, and its resource advantages are difficult to transform into economic advantages. [0003] Low-temperature dry distillation of lignite adopts coal pyrolysis processing technology to heat coal to 550°C to 600°C in the absence of air to remov...

AI Technical Summary

Problems solved by technology

Disadvantages of this process: high requirements on lignite particle size and coal quality, suitable for middle-aged and old lignite; single processing capacity is small, waste water is large, serious pollution, poor environmental protection

The internal heat type solid heat carrier method, which is represented by Lurgis Rulges low-temperature dry distillation method (abbreviated as L-R method), has the disadvantages of this process: the output of semi-coke is small, there are many liquid products, there are many impurities, and there is a lot of gas output. It is only suitable for Used for city gas; single unit has small processing capacity, large amount of waste water, serious pollution, and poor environmental protection

[0006] At present, lignite upgrading technology at home and abroad is still immature. In order to achieve large-scale production and low pollution environmental protection indicators, targeted development of lignite upgrading technology will be the research direction of comprehensive utilization of lignite resources

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