Step-by-step low-temperature carbonization system of brown coal

Abstract

The invention relates to a step-by-step low-temperature carbonization system of brown coal. The step-by-step low-temperature carbonization system comprises a drying stage, a carbonization stage, a waste heat recovery stage and a cooling stage, wherein coal is heated to 180-300 DEG C under the condition of isolating air through a gas heat carrier so that more than 90% of all water, crystal water and partial oxygen-containing functional groups influencing the heat value of the coal are removed and heating components of the coal are enriched; and the coal is continued to be heated to 550-600 DEG C to form semicoked solid, the separated volatile matters are purified and recovered to obtain coal tar and coal gas products, and the high-temperature semicoked solid is subjected to the waste heat recovery stage and is cooled to 60 DEG C to be collected to obtain semicoked products, wherein the obtained semicoked products have the advantages of high heat value, good stability, hydrophobicity and the like. The step-by-step low-temperature carbonization system of the brown coal, disclosed by the invention, has the advantages of simple process, low energy consumption, no need of industrial water, no generation of waste water and no emission of harmful gas, and is a highly-automatically coal treating system for treating a large amount of coal; and each component adopts modularized design and can be matched according to yield requirements.

Description

technical field [0001] The invention belongs to the technical field of internal heating type gas heat carrier lignite dry distillation, and in particular relates to a step-by-step low-temperature lignite dry distillation system. 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...

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 impuri

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