压块工艺条件下配煤对活性炭孔结构的调控作用
Regulation effect of blending coal on pore structure of coal-based activated carbon prepared by briquetting method
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摘要: 以大同烟煤为主料,分别和太西无烟煤、霍林河褐煤配煤,采用无黏结剂直接压块工艺制备活性炭,为了研究配煤对活性炭孔结构的调控作用,烟煤和配煤按照质量比100∶0、80∶20、60∶40、40∶60、20∶80进行试验,以碘值、亚甲蓝值和焦糖脱色率作为评价指标,利用密度函数理论解析温度77 K下N2的吸附/解吸曲线,得出活性炭孔容和孔径分布。结果表明:无烟煤和褐煤作为烟煤的配煤制备活性炭会使其孔结构向着不同的方向发育。配入无烟煤促使活性炭以产生新的微孔为主,向着微孔更丰富,总孔容更大的方向发育,碘值和亚甲蓝值随着无烟煤配比的提高而增加,由579 mg/g和128 mg/g分别增加至979 mg/g和135 mg/g;配入褐煤导致微孔短暂的发育后进入扩孔阶段,以至于总孔容减少,中孔容增加,在烟煤和褐煤质量配比在20∶80时,碘值、亚甲蓝值和焦糖脱色率分别为681 mg/g、87 mg/g和18%。Abstract: A series of activated carbon were prepared by briquetting method from Datong bituminous coal and Taixi anthracite coal or Huolihe lignite blending with out binder.In order to investigate regulation effect of blending coal on pore structure of activated carbon, the experiments of mass ratio 100 : 0, 80 : 20, 60 : 40, 40 60 and 20 : 80 of bituminous coal and blending coal were carried out.The pore structure of activated carbons samples were characterized by iodine number, methyle ne blue value and caramel decolored ratio, besides its pore volume and pore size distribution (PSD) were obtained using Density Functional Theory (DFT) to calculating N2 adsorption/desorption isotherm of nitrogen at 77 K. The results show that anthracite coal or lignite as blending coal make the pore development to the different direct ion.' The blend of anthracite coal can prompt generating new micropores, enriching microspores and improving total pore volume.The iodine number and methylene blue value of activated carbon samples were gradually increased with the growth of anthracite coal mass ratio, which from 579 mg/g and 128 mg/g to the 979 mg/g and 135 mg/g respectively.However, lignite blending with bituminous coal lead to transition to expanding pore stage after a short period of time development of micropores, decr easing total pore volume and improving mesopore volume.The activated carbon prepared in the mass ratio 20 : 80 of bituminous coal with lignite has an iodine number of 681 mg/g, methylene blue value of 681 mg/g and caramel decolored ratio of 18%.