Brown coal dry-distillation method using coal hot air furnace to supply heat

Abstract

The invention relates to a brown coal dry-distillation method using a coal hot air furnace to supply heat. The brown coal dry-distillation method comprises the following steps of: adding brown coal in a drying furnace to be heated and dried, sending the heated coal into a dry-distillation furnace to be heated and dry-distilled to obtain thermal carbocoal, cooling and quenching the thermal carbocoal in a quenching furnace to obtain a carbocoal product; purifying high-temperature smoke produced by the coal hot air furnace in a purifying room, making dry-distilled coal gas enter into the purifying room, consuming residual oxygen in the high-temperature smoke to produce high-temperature hot air with a low oxygen content as all or partial heating sources of the drying furnace used for coal drying, wherein the dry-distilled heat source in the dry-distillation furnace partially or all comes from the high-temperature smoke produced by burning the dry-distilled coal gas in a burner, and obtaining crude tar and clean dry-distilled normal-temperature coal gas after the following treatments: de-dusting and cooling the dry-distilled coal gas and tar steam, and separating tar and on the like. Compared with the method taking the dry-distilled coal gas as the heat source drying heat source, the high-temperature smoke of the coal hot air furnace is used as the brown coal drying heat source, a lot of dry-distilled coal gas is surplus, such that the saved plenty of dry-distilled coal gas can be for other uses and thus the economic value is high.

Description

technical field [0001] The invention relates to a coal dry distillation process, in particular to a lignite dry distillation process using a coal-fired hot blast stove as a system heat supply. Background technique [0002] The process in which coal is thermally decomposed into coal gas, tar, coke (or semi-coke) and other dry distillation products under the condition of isolation of air is called coal dry distillation process, which can be divided into high temperature, medium temperature or high temperature according to the final temperature of the coal material. Low-temperature carbonization is generally considered to be low-temperature carbonization at 500-700 ° C. High-volatility classified coals such as lignite, long-flame coal, or gas coal are suitable for low-temperature carbonization. At present, most of the carbonization furnaces used for this type of coal are Lurgi three-stage furnace or Vertical blue charcoal square furnace, its combustion heating method is mostly ...

AI Technical Summary

Problems solved by technology

However, in the current dry distillation process of this type of coal, the required heat source for dry distillation comes from the gas generated by system dry distillation, that is, the dry distillation gas is used for low-end purposes such as combustion heat supply, and the coke quenching or tail gas waste heat cannot be recovered well. Or use, resulting in a large amount of waste of high-grade heat

However, low-rank coals such as lignite have a high water content (between 25% and 65%) and require a lot of heat to dry them. When using advanced technology and equipment to process low-rank coal such as lignite, the process itself consumes all or most of the carbonization gas, and there is no or very little gas output for external supply.

At the same time, the existing technology and devices only use lump coal, and a large amount of finely crushed coal or pulverized coal produced in the mining, crushing and screening process cannot be used, resulting in a waste of a large amount of valuable resources, and its economic benefits are limited

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