焦炭对焦油模型化合物的催化裂解实验研究

EXPERIMENTAL STUDIES ON COKE CATALYST FOR CRACKING OF BIOMASS TAR MODEL COMPOUND

研究焦炭对焦油模型化合物的催化裂解。考察焦炭对甲苯、甲苯与萘、甲苯与苯酚的催化裂解率及析炭率。结果表明:焦炭对甲苯的催化裂解率与同温度下的热裂解率相当,分别为61.68%与59.02%,析炭率有所降低,由8.54%变为4.16%;对萘的催化裂解率也与同温度下的热裂解率相当,分别为57.95%与56.20%,析炭率也有所降低,由20.72%变为11.89%;而焦炭对苯酚的裂解率与同温度下热裂解率相比有明显增加,由38.25%增加到97.41%,析炭率同样有所降低,由10.96%变为7.03%;说明焦炭对焦油中的组分有选择催化裂解作用。对上述反应前后焦炭样的XRD分析,发现反应后析出的炭与作为催化剂的炭是同一晶型的炭,对末裂解冷凝液的GC-MS分析,发现焦油模型化合物通过裂解后有少部分向芳香化程度增加的方向进行转化。

An experimental study on catalytic cracking of tar model compound-toluene, toluene and naphthalene, toluene and phenol over coke catalyst was done. The experimental results showed that compared thermal cracking with catalytic cracking using coke as the catalyst, the cracking efficiency of toluene are 61.68% and 59.02% re- spectively, nearly the same. The deposit carbon efficiency decreased from 8.54% to 4.16% by catalytically crack- ing. The cracking efficiency of naphthalene are nearly the same, 57.95% and 56.20% respectively, and the de- posit carbon efficiency also decreased from 20.72% to 11.89% by catalytically cracking. However, the cracking efficiency of phenol greatly increased from 38.25% by thermal cracking to 97.41% by catalytic cracking. What＇s more, to phenol, the deposit carbon efficiency came down from 10.96% to 7.03%. The results provide an experi- mental thinking for selective catalytic cracking of tar model compound. The XRD analysis revealed that coke before and after cracking reaction were the same crystal form. Furthermore, the GC-MS analysis illustrated tar model com- pound after pyrolysis contained a large amount of PAHs.