轻烃在积炭催化剂上的裂解反应性能研究

为了减少多产低碳烯烃的催化裂化过程中轻烃二次反应的氢气、甲烷和焦炭等副产物产率，以炼油厂轻烃和2-甲基-2-丁烯为原料，在小型固定流化床装置上考察了反应温度和催化剂床层密度对轻烃裂解反应性能的影响，探讨轻烃反应条件与副产物的关系；并以回炼油或常压渣油为积炭前体，将其与再生剂反应，形成一系列不同积炭覆盖程度的积炭催化剂，进一步考察轻烃在积炭催化剂上的裂解反应性能。结果表明：提高反应温度和催化剂床层密度都能使丙烯收率提高，但是提高反应温度会引起氢气和甲烷产率快速增长，而提高催化剂床层密度则会引起焦炭产率快速增长；轻烃在积炭催化剂上反应时氢气、甲烷和焦炭的总产率明显降低，而丙烯收率基本不变；积炭催化剂经多次循环使用后，仍可保持较好的轻烃裂解反应性能，具有良好的活性稳定性；以回炼油为前体的积炭催化剂的性能优于以常压渣油为前体的积炭催化剂。

EFFECT OF CARBON DEPOSITION ON REGENERATED FCC CATALYST ON LIGHT HYDROCARBON CRACKING REACTION

To reduce the yield of hydrogen, methane and coke in the secondary reaction of light hydrocarbon in FCC process for more low carbon olefins，the effect of reaction temperature and catalyst bed density on the catalytic cracking of light hydrocarbon and 2-methyl-2-butene on coked regenerated FCC catalyst was investigated in a small fixed-fluidized bed reactor. A series of coked catalysts with different carbon deposition was made by reaction of regenerated catalyst with heavy cycle oil (HCO) or atmospheric residue and used for catalytic cracking of light hydrocarbon test. The experiment results show that the yield of propylene rises with increasing reaction temperature and catalyst bed density, but the yield of hydrogen and methane increases rapidly at high temperature. The increase of catalyst bed density causes rapid growth of coke yield. Compared with the results on the regenerated catalyst, the total yields of hydrogen, methane and coke on the coked catalyst significantly decrease and yield of propylene is almost unchanged. Even if the coked catalyst is recycled many times, the cracking activity for light hydrocarbon still remains stable. The performance of the coked catalyst obtained with HCO is better than the coked catalyst obtained with residue oil.