泡沫炭催化剂对低阶煤热解焦油改质的影响

Effect of Carbon Foam Catalyst on Tar Upgrading During Low Rank Coal Pyrolysis

以柳林煤(LL)为原料,采用自发泡法制备生成了泡沫炭催化剂(CF1、CF2、CF3),在700℃的条件下分别对新疆淖毛湖长焰煤(NMH)和内蒙古胜利褐煤(SL)进行了Py-GC/MS热解实验,考察了不同孔结构泡沫炭对热解气态焦油产物分布的影响。研究结果表明:相较于半焦催化剂(SC),泡沫炭催化剂对提高煤热解焦油品质有着更为显著的优势。泡沫炭催化剂的催化性能与其孔结构、化学结构密切相关。CF1作用后,NMH、SL热解气态焦油总产量有了显著提高(分别增加了10.26%和31.31%),这与其合适的比表面积(281.14 m^(2)/g)、丰富的微孔结构(微孔面积占比88.96%)、适宜的反应活性相关。具备丰富多级孔结构、反应活性更高的CF2、CF3,使得NMH、SL热解焦油总产量降低。此外,CF系列催化剂均提高了煤焦油中轻质芳烃相对含量,且降低了含O、N、S化合物的相对含量。这说明CF催化剂可明显促进NMH及SL热解反应中的催化裂解、脱氧、芳构化等反应的发生,定向调控煤热解气态焦油产物。

Carbon foam catalysts(CF1,CF2,CF3)were prepared by spontaneous foaming method using Liulin coal(LL)as raw materials,and the pyrolysis experiments of Xinjiang Naomaohu long-flame coal(NMH)and Inner Mongolia Shengli lignite coal(SL)were performed by Py-GC/MS at 700℃.The effects of carbon foam catalysts with different pore structure on the distribution of gaseous tar products were investigated.The results show that compared with normal semicoke catalyst(SC),carbon foam catalysts have more significant advantages in improving the quality of tar from coal pyrolysis.The catalytic performance of carbon foam catalysts is closely related to its pore structure and chemical character.After the action of CF1,the total amount of tar during pyrolysis of NMH and SL is significantly increased(the increase rates are 10.26%and 31.31%,respectively),which is related to its suitable specific surface area(281.14 m^(2)/g),rich micropore structure(microporous area accounts for 88.96%of the total specific surface area),and appropriate reactivity.CF2 and CF3 with rich hierarchical pore structure and higher reactivity make the total amount of NMH and SL tar decrease.In addition,the relative content of light aromatic hydrocarbons in gaseous tar of coal pyrolysis increases and the relative content of compounds containing O,N and S decreases by CF catalysts.These results indicate that these CF catalysts can significantly promote catalytic cracking,deoxidation,aromatization,and other reactions during the pyrolysis of NMH and SL,and can directionally control the distribution of gaseous tar from coal pyrolysis.