Quality-improving technique combining low-rank coal pneumatic drying with multi-tube revolving dry distillation and system for same

Abstract

The invention discloses a quality-improving technique combining a low-rank coal pneumatic drying with a multi-tube revolving destructive distillation and a system for the same, wherein the technique comprises a coal flow and a hot smoke flow, and both of the coal flow and the hot smoke flow comprise a drying process and a destructive distillation process which are connected with each other; the system comprises a gas flow drying system and a multi-tube revolving destructive distillation system which are connected with each other. The quality-improving technique combining a low-rank coal pneumatic drying with a multi-tube revolving destructive distillation and the system for the same disclosed by the invention realize a cascade efficient utilization for a high-temperature smoke, and increase the energy utilization rate of the whole system. The quality-improving technique combining a low-rank coal pneumatic drying with a multi-tube revolving destructive distillation and the system for the same disclosed by the invention have the advantages of high energy utilization rate, safe and stable system, small treatment capacity for destructive distillation gas, small treatment capacity for coking wastewater, high yield of tar, high calorific value of coal gas etc. The quality-improving technique combining a low-rank coal pneumatic drying with a multi-tube revolving destructive distillation and the system for the same disclosed by the invention also can recover chemical raw materials such as coal tar generated during a low-rank coal low-temperature destructive distillation process, and increase the comprehensive utilization rate of coal. Via the technique, a powdery or granular semicoke which is low in volatile matter, high in low caloric value and good in stability is produced by a quality-improving technique using a low-rank coal low-temperature destructive distillation. The technique is suitable for producing a civil or industrial coal gas with a medium caloric value by a quality-improving technique using a low-rank coal low-temperature destructive distillation.

Description

technical field [0001] The invention relates to a low-rank coal upgrading process and system, in particular to a high-moisture low-rank coal airflow drying and multi-tube rotary dry distillation combined upgrading process and system. Background technique [0002] Low-rank coal includes lignite, long-flame coal, non-caking coal, weakly caking coal, gas coal, peat, etc., accounting for more than 60% of my country's coal reserves, mainly distributed in Yunnan, Inner Mongolia, Northeast China, Sichuan and other places. It is characterized by high water content, generally above 20%; high volatile content, about 30-50%; low calorific value, about 2500-4500 kcal / kg. [0003] At present, the mining and utilization of coal resources in my country are mainly anthracite and bituminous coal, and the mining and utilization of low-rank coal are low, mainly as power coal for power plants. Due to its high water content, direct combustion has the disadvantages of difficult combustion and lo...

AI Technical Summary

Problems solved by technology

The process and system adopt the combined upgrading method of airflow drying and multi-tube rotary low-temperature dry distillation, which solves the problems of large coking wastewater treatment capacity and large gas treatment capacity in the simple dry distillation process. At the same time, the hot flue gas after dry distillation is introduced into the drying The system is used as a heat source, which realizes the cascade effective utilization of high-temperature flue gas and improves the energy utilization rate of the entire system

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