4.2.1 Definition
The process to convert biomass solid raw material into fuel gas or chemical feedstock gas (syngas) is called gasification or thermochemical gasification.
4.2.2 Classification of gasification method
Gasification methods are classified according to combinations of conditional factors shown in Table 4.2.1..
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Table 4.2.1 Classification of Gasification Method
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Classification
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Conditional factor
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Gasification pressure
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Normal pressure (0.1-0.12 MPa), High pressure (0.5-2.5 MPa)
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Gasification
temperature
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Low temperature (700oC and below), High temperature (700 oC and above),
High temperature decomposition (ash fusion point and above)
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Gasification agent
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Air, oxygen, steam and combination of them, carbon dioxide for particular time
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Heating
(Temperature zone formation)
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Direct gasification (heat generation from reaction of partial gasification raw material and oxygen)
Indirect gasification (heating raw material and gasification agent by external heat)
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Gasifier types
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Fixed bed, flow bed, circulating flow bed, entrained bed, mixing bed, rotary kiln, twin tower, molten furnace
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