淀粉粘结剂对CH_4/N_2分离效果及GAC孔结构影响

Influences of Amylaceous Binders on Separation Effect of CH_4/N_2 and Pore Structure of Granular Activated Carbon

以褐煤为原料,分别采用可溶淀粉、天然淀粉、食用淀粉作为粘结剂,制备作为变压吸附(PSA)分离CH4/N2吸附剂的3种颗粒活性炭(GAC):GAC-T、GAC-NS、GAC-TS,考察了淀粉种类及用量对CH4/N2分离效果及GAC孔结构的影响。GAC-T的CH4/N2分离效果优于GAC-NS、GAC-TS,三者的分离效果均随着淀粉用量的增加而降低。当淀粉用量相同时,淀粉种类对GAC孔结构具有较大影响,0.40～0.65nm、0.65～0.85nm孔径范围的孔分布差异是造成分离效果差异的主要因素。淀粉用量的增加有利于小于0.65nm的微孔形成,不利于适宜CH4/N2分离的0.65～0.85nm微孔的形成。

Three kinds of granular activated carbons （GAC） , namely GAC-T, GAC-NS and GAC- TS used for separation of CH4/N2 by pressure-swing adsorption （PSA）, are prepared from lignite by using tragantine, natural starch and salep as binders, respectively. The influences of starch kind and consumption on separation effect of CH4/N2 and pore structure of GAC are investigated. The separation effect of CHJNz by GAC-T is better than those by GAC-NS and GAC-TS, and their separation performances decrease with the increase of starch consumption. When the consumptions of starches are same, the pore structure of GAC is mainly influenced by starch kinds. The difference in pore size between 0.40 to 0.65 nm and 0.65 to 0.85 nm is the important factor affecting the separation effect. The increase of starch consumption is favorable for formation of micropore of less than 0.65 nm, while it is unfavorable for formation of micropore of 0.65 to 0.85 nm suitable for separation of CH4/N2.