Clean coal pressurized fluidized bed slag gasification process and system

Abstract

The invention discloses a clean coal pressurized fluidized bed slag gasification process and system. By means of the gasification process and system, the problems that an existing pressurized fluidized bed industrial gasification process is complex, poor in coal applicability, low in gasification pressure, small in production capacity and low in gasification efficiency, the environment is polluted are solved. According to the technical scheme, the process includes the steps that raw material coal powder is pressurized and sent to a fluidized bed gasification furnace through a material inlet to react with a gasifying agent in a gasification mode, and crude synthesis gas and coal powder ash slag are obtained; the crude synthesis gad rises and is sent to a multi-pipe type cyclone separator through a top outlet of the fluidized bed gasification furnace to be dedusted, fluidizing agents are sprayed twice through a gasification spray nozzle to improve gasification efficiency, the coal powder ash slag is melt through a slag melting device, forms melt slag and then enters a slag quenching tank through a bottom outlet of the fluidized bed gasification furnace to be quenched and discharged through a slag locking hopper. The clean coal pressurized fluidized bed slag gasification process and system are simple in process, easy and convenient to operate, wide in coal applicability, high in gasification pressure, large in production capacity, high in gasification efficiency and environmentally friendly.

Description

technical field [0001] The invention relates to a coal gasification process and system, in particular to a clean coal pressurized fluidized bed slag gasification process and system. Background technique [0002] Coal gasification technology can be divided into three types of gasification technologies: fixed bed gasification, fluidized bed gasification and entrained bed gasification according to the structural characteristics of the gasifier and the movement mode of the fuel during conversion in the gasifier. According to the investigation and analysis of various fixed bed, fluidized bed and entrained bed coal gasification technologies that have been widely used in my country, it can be seen that although the investment of fixed bed gasification technology is relatively low, its development is subject to certain restrictions due to environmental protection issues. However, although the entrained bed gasification technology is advanced, clean and environmentally friendly, due t...

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Problems solved by technology

However, the current industrialized fluidized bed gasification technology still has the following shortcomings and deficiencies: 1) The coal types of the current fluidized bed gasification technology are generally poor in adaptability, which is affected by the low gasification temperature and the dry method. The impact of slagging is generally only suitable for coal types with good reactivity and weak slagging; 2) Due to the low gasification pressure of the current fluidized bed gasification technology, the amount of dust carried over from the crude gas is high, and the dust removal effect is poor, resulting in When the waste heat boiler is used to recover the heat of crude gas, it is easy to cause problems such as blockage and abrasion of the waste heat boiler; 3) Due to the low gasification temperature of the current fluidized bed gasification technology, the crude gas is easy to carry macromolecular organic substances such as tar, which is easy to cause subsequent Blockage of pipelines and equipment; 4) Due to the dry slagging method, it is not suitable for gasification of coal with low ash melting point, and in order to control the gasification reaction temperature, the steam consumption is large and the waste water discharge is large; 5) The current flow There are many problems in the dry slagging system of bed gasification technology, which affects the long-term stable operation of the gasifier; 6) The carbon conversion rate and gasification efficiency in the gasifier are not high, and there are many unreacted carbon residues in the coal , the carbon content in slag and ash is high; 7) Due to the low gasification efficiency, the amount of dust carried out in the crude gas is relatively high, and it is easy to carry macromolecular organic substances such as tar, which makes subsequent sewage treatment difficult

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