Low-rank coal multi-stage fluidized bed coal chemical industry multiple production system and method

Abstract

The invention provides a low-rank coal multi-stage fluidized bed coal chemical industry multiple production system. The low-rank coal multi-stage fluidized bed coal chemical industry multiple production system comprises a fluidized bed drying furnace, a fluidized bed pyrolyzing furnace and a fluidized bed boiler, wherein the fluidized bed drying furnace, the fluidized bed pyrolyzing furnace and the fluidized bed boiler are connected in series and respectively adopt a fluidized bed form; the fluidized bed drying furnace is used for drying low-rank coal to perform physical dehydration on the low-rank coal, a tube plate heat exchanger is arranged in the fluidized bed drying furnace, the tube plate heat exchanger is immersed in the low-rank coal, and a gas heat medium in the tube plate heat exchanger is overflowed from the low-rank coal so as to carry out removed water in the low-rank coal; the fluidized bed drying furnace is connected with the fluidized bed pyrolyzing furnace, and the fluidized low-rank coal after drying enters the fluidized bed pyrolyzing furnace for performing medium and low-temperature pyrolysis in the fluidized bed pyrolyzing furnace; and the fluidized bed boiler is connected with the fluidized bed pyrolyzing furnace, and coal char generated by pyrolysis in the fluidized bed pyrolyzing furnace can enter the fluidized bed boiler for combustion.

Description

technical field [0001] The invention relates to a low-rank coal chemical industry system, in particular to a low-rank coal multi-stage fluidized bed coal chemical polygeneration system and a method thereof. Background technique [0002] my country is rich in lignite reserves. In 2010, lignite output exceeded 300 million tons, accounting for 10% of the national coal output. The efficient processing and utilization of lignite has become a highly concerned issue in the field of coal energy in my country. [0003] Due to the short coal-forming period of lignite, its water content, oxygen content and volatile matter are high, and the total water content is as high as 20-60%. On the one hand, it leads to low calorific value, which is not suitable for direct combustion; on the other hand, it causes high chemical reactivity, which is easily weathered and broken in the air, and is not suitable for long-distance transportation and long-term storage. Therefore, the largest use of lig...

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Problems solved by technology

[0004] In the traditional low-rank coal circulating fluidized bed boiler power generation technology, the coal is directly burned or pyrolyzed, but the water contained in the low-rank coal is as high as 30-60%. First, it is directly evaporated, which wastes water. The latent heat of evaporation, water resources have not been fully utilized; the second is to increase the production of phenolic ammonia wastewater in the pyrolysis process, which is difficult and expensive to treat, which brings great pressure to environmental protection

At present, my country's coal-producing areas are basically water-deficient areas. For water-deficient areas with an annual processing capacity of several million tons, this is a very large waste. It is necessary to improve the process to recover these water and reuse it to reduce system energy. consumption, and the need to reduce the pressure on the phenolic ammonia wastewater treatment system

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