Process and device for dry distillation of lignite on basis of coke-carried heat

Abstract

The invention provides a process and a device for the dry distillation of lignite on the basis of coke-carried heat, particularly for the dry distillation and intensive processing of low-grade lignite. The device of the invention mainly comprises a crushing and screening device, a drying bed, a separator, a primary dry distiller, a secondary dry distiller, a combustion bed and an oil-gas separation system. The process of the invention comprises the following steps: crushing and screening lignite before being fed into the drying bed; drying the lignite by the flue gas from the combustion bed and feeding the dried lignite into the primary dry distiller; dry-distilling the lignite at certain temperature by the hot coke from the combustion bed and the coal gas of the secondary dry distiller as the heat carrier and carrier gas respectively; feeding the obtained oil and gas into the oil-gas separation system, and allowing the solid product to drop into the secondary dry distiller to carry out the secondary dry distillation on the solid product by the hot coke and high-temperature coal gas as the heat carrier; and cooling and feeding the obtained semi-coke product into a storage tank or the combustion bed for cycle use, wherein the hot coke and high-temperature flue gas are provided by the combustion bed through oxygen-controlled combustion. The invention has the advantages of small investment, even heat transfer, high rate, low heat consumption, high yield of semi-coke, tar and coal gas and the like.

Description

technical field [0001] The invention relates to a lignite dry distillation process and device based on coke heat carrying, which is used for preparing semi-coke, tar and gas through pyrolysis of lignite and other low-quality coal, and can be applied to coal, coal chemical industry, energy and power, heating and power supply, etc. industry, which belongs to the field of energy utilization equipment and method improvement. Background technique [0002] Although my country's coal resources are relatively rich, high-quality coal resources only account for about half, and the rest are lignite and other coal resources. Lignite and other coals are often regarded as low-quality fuel power coal due to their high moisture content, high ash content, high volatile content, and low calorific value. In addition, they are prone to oxidation and spontaneous combustion, making them unsuitable for long-distance transportation. Therefore, they have become coal resources that are difficult to p...

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Problems solved by technology

[0013] The above process equipment has a good effect on lignite upgrading, but there are generally disadvantages such as high energy consumption and water consumption, some devices occupy a large space, heavy equipment, and high investment costs, and some processes are limited to lignite upgrading without real implementation. Pyrolysis produces tar and coke oven gas, or there are problems such as low oil and gas yields, and some processes are limited by the technical level and the scale cannot be industrialized

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