High-efficiency lignite low-temperature dry distillation quality-enhancing process by using dry distillation coal gas as heat-carrying medium

Abstract

The invention relates to a low-temperature dry distillation process for coal, in particular to a high-efficiency lignite low-temperature dry distillation quality-enhancing process by using dry distillation coal gas as a heat-carrying medium. The process comprises a coal-preparing flow, a drying flow, a dry distillation flow, a heat source flow, a coal gas and tar processing flow and a semicoke cooling transfer flow; in the process, vapor self-generated by a drying tower is used as a drying medium, the coal gas of a generator is taken as a heat source to heat the self-generated dry distillation coal gas, and serves as a dry distillation medium, and the coal gas of the generator is used as fuel of a hot air furnace; the dry distillation semicoke is cooled in a cooling mode of drying fume exhaust plus semi water spraying; and condensation water is used for coke-quenching water, a gasifier of the coal gas of the generator and a tar cooling agent. The process has the advantages of producing high-index dry coal and dry semicoke, high-heating value coal gas and high-quality tar, having a flawless and high-efficiency energy recycling system, not using outside nature water, hardly discharging water to the outside, saving huge cost for sewage treatment, creating the maximum economic benefits for customers and having quite strong competitive power on economy, technology and market.

Description

technical field [0001] The invention relates to a coal low-temperature dry distillation process, in particular to a high-efficiency lignite low-temperature dry distillation process using dry distillation gas as a heat carrier. Background technique [0002] At present, the known low-temperature dry distillation process of lignite uses the flue gas generated by the hot blast stove as the heat carrier for drying and dry distillation, and the energy utilization efficiency needs to be improved in the connection of the whole process flow. There are following disadvantages in the known lignite low-temperature dry distillation process: [0003] 1. The fly ash in the flue gas enters the processed coal, resulting in an increase in the ash content of the processed coal. [0004] 2. When the air consumption coefficient of the hot blast stove is not well controlled, the hot flue gas contains more oxygen, which increases the possibility of coal dust and gas explosion and deteriorates the...

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Problems solved by technology

[0009] The present invention aims to solve the problems of poor safety, low thermal efficiency, high inert components of gas, large dust content of tar, large external exhaust pollution and high cost of sewage treatment in traditional coal drying and low-temperature carbonization processes, and provides a dry distillation gas as a carrier Thermal high-efficiency lignite low-temperature carbonization upgrading process, which uses the producer gas as the heat source to heat the self-produced carbonization gas to dry the lignite, so as to reduce the content of inert gas in the carbonization gas and increase the calorific value of the carbonization gas; it does not use traditional hot blast furnace smoke Gas is directly used as the desiccant, but the self-produced steam is used as the desiccant to ensure the safety and efficiency of the drying system; the traditional wet coke quenching method is not used, but the dry-wet coke quenching method is used to avoid semi-coke double coke No secondary immersion phenomenon, save secondary drying process, save secondary drying energy and avoid secondary pollution of water resources

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