改性铂锡重整催化剂上甲基环戊烷的转化规律

以五元环烷烃中最难转化的甲基环戊烷为模型化合物,考察了碱金属K、稀土金属以及反应温度对甲基环戊烷转化的影响规律。结果表明:在铂锡双金属催化剂下,510℃以上高温有利于甲基环戊烷的转化,但在实验温度范围内对脱氢异构产物苯的选择性影响不大,高温和低空速更促进裂解反应;添加适量碱金属K,降低了催化剂的酸性,裂解反应减弱,液体收率增加,甲基环戊烷转化率有所下降,产物苯的选择性未受到显著影响;添加稀土金属,甲基环戊烷裂解反应减弱,液体收率增加,较低空速条件下510℃时苯的选择性略有升高,较高空速下转化率降低,540℃时苯选择性下降明显。

STUDY OF CONVERSION MECHANISM OF METHYLCYCLOPENTANE OVER MODIFIED Pt-Sn REFORMING CATALYST SYSTEM

Using methylcyclopentane thatis most difficult to convert in five membered ring hydrocarbonas a model compound, the conversion situation of methylcyclopentane was investigated over the addition of alkali metal potassium and rare earth metal and reaction temperature. The results Indicated that under the Pt-Sn reforming catalysthigh temperature (≥510 ℃) benefit the conversion improvement of methylcyclopentane, while the selectivity of Heterogeneous dehydrogenation products—benzene was little affectedwithin the experimental temperature range and the process conditions of high temperature and lower liquid hourly space velocity can improve pyrolysis product’s selectivity; The addition of alkali metal K in moderation resulted that the acidity of catalysts reduced, cracking reaction weakened, liquid yield increased, methylcyclopentane’s conversion dropped, and the selectivity of benzene was not affected; The addition of bi-Rare earth metal made that cracking reaction weakened, liquid yield increased, benzene selectivity was slightly increased (510 ℃) in lower LHSV, conversion of methylcyclopentane and benzene selectivity obviously fell in higher LHSV.