不同煤阶煤炭化过程中挥发分组成及微孔变化的研究

Study on variation of micro-pores(<100 nm) and volatile components of different rank coals during carbonization

用SORPTOMATIC1990吸附仪研究了6种不同煤阶煤(包括无烟煤、贫瘦煤、焦煤、肥煤、弱黏煤、气煤)在3℃/min升温速率到1000℃的炭化过程中孔容和孔径随温度的变化规律,并用Bio-rad FTS-165裂解红外测定了各种煤在10℃/min升温速率的炭化过程中挥发分的组成及各自的释放温度范围.结果表明:不同变质程度煤在裂解过程中,可挥发性芳香物生成量的大小排序为肥煤>焦煤>瘦煤>气煤,且肥煤芳环上的取代基最多,而弱黏煤和无烟煤生成可挥发性芳香物的量最少.煤阶越低,释放CO2的温度越低,生成的量越多.1000℃生成焦炭的孔容大小排列为:肥煤C1>弱黏煤D1>焦煤B1>无烟煤YQ,比表面积大小排列为C1 YQ,B1>D1,平均孔半径大小的排列为:D1 B1>YQ>C1.在炭化过程中,C1肥煤的孔容和比表面积变化最剧烈,YQ煤变化最小.C1煤生成焦炭表面积最大为20 m2/g,其它煤成焦表面积3 m2/g.

6 different rank coals （including anthracite, lean coal, coking coal, fat coal, weakly-caking coal and gas coal） were carbonized at 3 ℃min in crucibles up to 1 000 ℃. The pore volume and pore diameter of chars and cokes produced at different final temperatures were analyzed by SORPTOMATIC1990 adsorber. Bio-rad FTS - 165 pyrolysis-ir was used to measure six coals volatiles component and their releasing temperature domain at 10 ℃/min. It showed that during carbonization the quantity of produced volatile aromatics ranked by fat coal C1 〉 coking coal B1 〉 lean coal A5 〉 gas coal Y1. The quantity of hydroxyl group and carbonyl group released by fat coal C1 is the most in the six coals. The yield of aliphatic hydrocarbon ranked by C1 〉 B1 〉 A5, Y1. Except for CO2, the quantity of all kinds of groups released by weak-caking coal D1 is the least in the six coals. At 1 000 ℃, the rank of coke pore volume is C1 〉 D1 〉 B1 〉 YQ, and coke average pore radius rank is DI〉〉B1 〉 YQ 〉 C1. C1 coal produced coke with the largest specific surface area, about 20 m^2/g, and other three coals all produce coke with specific surface area about 3 m^2/g.