The cyclone bed method for pulverized coal gasification
Technical field
The present invention relates to a kind of method for pulverized coal gasification, relate in particular to a kind of cyclone bed method for pulverized coal gasification.
Background technology
Enter 21 century, coal-fired in order to reduce to atmospheric pollution, must greatly develop clean coal technology.Gasification of coal be clean, efficiently utilize one of the main approach of coal, be the most important monotechnics of the modern Coal Chemical Industry of development.Gasification of coal can be produced fuel gas, chemical industry synthetic raw gas, hydrogen fuel cell, coal gas combined cycle generation, synthetic natural gas etc.
Mode of motion when existing Coal Gasification Technology transforms in vapourizing furnace according to the constructional feature of coal gasifier and fuel is divided into: fixed bed gasification technology, fluidized-bed gasification technology and entrained flow bed gasification technology.Wherein the fixed bed gasification technology can only be used lump coal, can not use smalls or fine coal, and the maintenance and the working cost of equipment are higher, and pressurization static bed gasifying process also can produce objectionable impuritiess such as phenols, tar, and the gas purification treatment process is complicated, easily causes secondary pollution.In fluidized bed gasifying process, must keep certain carbon content in the vapourizing furnace, and lime-ash is difficult for separating from the bed of material under fluidized state, the flying dust and the carbon content in the lime-ash of discharge are all higher, and thermosteresis is bigger, needs to consider that effective flying dust reclaims and circulation.In addition, because the influence of gasification temperature, the gasification intensity of fluidized-bed gasification furnace is restricted, and efficiency of carbon conversion is lower, and the strong coal of cohesiveness also is not suitable for gasifying.Entrained flow bed gasification technology is divided into two kinds of wet method (coal water slurry) and dry method according to feeding manner.The equipment and the system of wet method charging are simple, but will consume a part of heat owing to mix people's water in the pulping process, and efficiency of carbon conversion in the gasification and caloric power of gas are lower than the vapourizing furnace of dry feed, and the inapplicable many coals of ash that contain; The preparation of coal in the dry feed, drying, pressurization and delivery system complexity, equipment is more, system's operation and equipment maintenance cost costliness.
Summary of the invention
The purpose of this invention is to provide a kind of cyclone bed method for pulverized coal gasification, this method synthesis the advantage of fluidized-bed gasification technology and entrained flow bed gasification technology,, in the cyclone bed vapourizing furnace, feed coals such as semicoke, brown coal are gasified and obtain coal gas as gasifying medium with oxygen and water vapour.
The objective of the invention is to be achieved through the following technical solutions:
Cyclone bed method for pulverized coal gasification of the present invention comprises the processing step of following order:
A, the feed coal that granularity is less than or equal to 3mm carry out drying and preheating in coal drying and preheating system, dry back total water is less than or equal to 8%, and preheating temperature is 200-300 ℃;
Two-way entered the cyclone bed vapourizing furnace about feed coal after B, drying and the preheating divided under the acting in conjunction of oxygen and water vapor mixture agent, carries out gasification reaction and prepare gasification gas under pressure≤3.0MPa and temperature 900-1500 ℃ condition;
C, gasification gas enter gas change heater and further cool off after cyclone bed top of gasification furnace Quench, purify in gas cleaning system then, and wherein part purification coal gas uses as Quench gas after the supercharging of Quench air compressor;
The water vapour that D, gas change heater are produced is after high pressure steam boiler is handled, and the oxygen of producing with oxygen generation system uses as gasifying medium.
As seen from the above technical solution provided by the invention, the cyclone bed method for pulverized coal gasification that the embodiment of the invention provides, owing to adopt cyclone bed as vapourizing furnace, the advantage of integrated fluidized-bed gasification furnace and airflow bed gasification furnace, device structure is simple, low cost of manufacture, the raw material treatment capacity is big, and is easy to operate.
Description of drawings
The process flow sheet of the cyclone bed method for pulverized coal gasification that Fig. 1 provides for the embodiment of the invention.
Among the figure: 1, crusher, 2, the drying and preheating device, 3, the coal lock hopper, 4, add coal bunker, 5, oxygen generation system, 6, the cyclone bed vapourizing furnace, 7, tornado dust collector, 8, gas change heater, 9, the Quench air compressor, 10, high pressure steam boiler, 11, gas cleaning system.
Embodiment
Below in conjunction with accompanying drawing the embodiment of the invention is described in further detail.
A kind of cyclone bed method for pulverized coal gasification of the present invention, its preferable embodiment comprises the processing step of following order as shown in Figure 1:
A, the feed coal that granularity is less than or equal to 3mm carry out drying and preheating in the drying and preheating device, dry back total water is less than or equal to 8%, and preheating temperature is 200-300 ℃;
Two-way entered the cyclone bed vapourizing furnace about feed coal after B, drying and the preheating divided under the acting in conjunction of oxygen and water vapor mixture agent, carries out gasification reaction and prepare gasification gas under pressure≤3.0MPa and temperature 900-1500 ℃ condition;
C, gasification gas enter gas change heater and further cool off after the Quench of cyclone bed vapourizing furnace top, purify in gas cleaning system then, and wherein part purification coal gas uses as Quench gas after the supercharging of Quench air compressor;
The water vapour that D, gas change heater are produced is after high pressure steam boiler is handled, and the oxygen of producing with oxygen generation system uses as gasifying medium.
In the cyclone bed fine coal gasification process of the present invention, feed coal is less than or equal to 8% at drying and preheating device inner drying to total water then through the particle diameter of crusher in crushing one-tenth≤3mm, and temperature is 200-300 ℃ after the preheating; Coal dust after the dry and preheating successively by the coal lock hopper with add coal bunker, through from the water vapour acting in conjunction of the oxygen of oxygen generation system and high pressure steam boiler about in the of following minute two-way enter the cyclone bed vapourizing furnace, under pressure≤3.0MPa and temperature 900-1500 ℃ condition, carry out gasification reaction and prepare gasification gas; The coal gas of high temperature of cyclone bed vapourizing furnace production carries out Quench on cyclone bed vapourizing furnace top, and Quench gas comes from the Quench air compressor; Coal gas after the Quench enters the tornado dust collector dedusting from the cyclone bed top of gasification furnace, clean coal gas enters gas change heater and further cools off, purify in gas cleaning system then, wherein part purification coal gas uses as Quench gas after the supercharging of Quench air compressor; The water vapour that gas change heater is produced is after high pressure steam boiler is handled, and the oxygen of producing with oxygen generation system uses as gasifying medium.
Specific embodiment:
Industrial scale with coal treatment capacity 2t/h is an example, and feed coal is broken into≤particle diameter of 1mm through crusher (1), then at drying and preheating device (2) inner drying to total water 8%, temperature is 250 ℃ after the preheating; Coal dust after the dry and preheating is successively by coal lock hopper (3) with add coal bunker (4), through from the water vapour acting in conjunction of the oxygen of oxygen generation system (5) and high pressure steam boiler (10) about in the of following minute two-way enter cyclone bed vapourizing furnace (6), under pressure 1.0MPa and 1000 ℃ of conditions of temperature, carry out gasification reaction and prepare coal gas; The coal gas of high temperature of producing carries out Quench on cyclone bed vapourizing furnace (6) top, and Quench gas comes from Quench air compressor (8); Coal gas after the Quench enters tornado dust collector (7) dedusting from cyclone bed vapourizing furnace (6) top, clean coal gas enters further cooling of gas change heater (9), purify in gas cleaning system (11) then, wherein part purification coal gas uses as Quench gas after Quench air compressor (8) supercharging; The water vapour that gas change heater (9) is produced is after high pressure steam boiler (10) is handled, and the oxygen of producing with oxygen generation system (5) uses as gasifying medium.
The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claims.