One Question per Day (February 23, 2018
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What are the requirements for the thermal stability standards of coal used in atmospheric pressure fixed-bed gasification? TS-6>80% is Grade I, >70~80% is Grade II, >60~70% is Grade III
TS-6>80% is Grade I, >70~80% is Grade II, >60~70% is Grade III
Thermal stability: Grade I >80, Grade II >70~80, Grade III >60~70 GB/T 1573
TS-6>80% is Grade I, >70~80% is Grade II, >60~70% is Grade III
1. The first thing to consider is the ash fusion point; a high ash fusion point is required, as only when it is high can the temperature of the oxide layer be increased, thereby ensuring furnace stability and enhancing the speed and completeness of the gasification reaction. 2. The adhesiveness should be assessed using simple observation methods; for example, based on the characteristics of the cinder obtained after testing the volatile matter yield, coal with cinder characteristics below level 3# should be selected for gasification. This ensures that the retorting layer does not develop severe adhesion, thereby preventing deterioration in furnace operation. 3. It is necessary to choose coal with a low ash content; a lower ash content may result in a higher fixed carbon content, which in turn increases the gas production. 4. It is necessary to choose coal with an appropriate volatile matter content. In the production of cold gas from bituminous coal, the volatile matter content of the coal should be moderate, namely between 22% and 30%. Excessively high ash content and high volatile matter content require a reduction in the fixed carbon content, which in turn undermines the gas production rate. In the production of hot gas from bituminous coal, the volatile content is high, allowing it to be mixed in gaseous form with the heating medium for combustion; therefore, the volatile content yield can be set at over 30%. 5. When selecting coal, its appearance should be examined, namely particle size, color, shape, and the amount of gangue. (1) Whether it is lump coal or briquetted coal – lump coal should be chosen. An appropriate particle size must be selected; for bituminous coal, a particle size of 25 mm to 100 mm is suitable, as coal with too fine particles should not be used, while for anthracite, larger lumps should not be chosen. (2) Whether it is bituminous coal or anthracite, its appearance should be a bright black color.
TS-6>80% is Grade I, >70~80% is Grade II, and >60~70% is Grade III.
TS-6>80% is Grade I, >70~80% is Grade II, and >60~70% is Grade III.
The thermal stability index is denoted by TS+6. Both the Coal Quality Standards for Fixed-Bed Gas Generators at Atmospheric Pressure (GB9143-88) and the Technical Specifications for Coals Used in Two-Stage Gas Generators (GB50195-94) specify that TS+6 > 60%.
TS-6>80% is Grade I, >70~80% is Grade II, >60~70% is Grade III
TS-6>80% is Grade I, >70~80% is Grade II, >60~70% is Grade III
Thermal stability: Grade I >80, Grade II >70~80, Grade III >60~70 GB/T 1573