Research On Long Lifetime Of Catalyst For M(B)TH Reaction

It is a potential way to gain clear fuel by conversion of small bio-oxygenates such as methanol, i-propanol and propanal. This can help our country solve the problem of energy shortage and environment pollution. This paper focuses on synthesis of long lifetime of catalyst, catalytic conversion of small oxygenate molecules and other problems related to reaction. The major content and results is as following:(a) The obtained hierarchical ZSM-5 is a mesoporous aggregate of ZSM-5 nanoparticles with a core/shell structure. The organic structure directing agents (OSDA), seed, and crystallization time are the conditions kinetically controlling the crystallization process. (b) Long lived methanol to hydrocarbon (MTH) catalyst was obtained by the rational post-engineering of ZSM-5 in FeF3/NH4HF2 media. Characterization results indicate that the improvement is achieved by the integration of selective extraction of the defect rich part, co-extraction of Si and Al and high dispersion of iron species in zeolite. (c) The functional groups in bio-oxygenates have a huge impact on catalytic performance. When i-propanol used on MTH reaction ZSM-5 catalyst has a longer catalytic lifetime than methanol. While in propanal case, all the ZSM-5 catalysts deactivated within 8 hours. The catalyst lifetime in methanol conversion reaction was dramatically improved after post-modification, but it didn't work on the propanal conversion reaction. (d) Selective conversion of small bio-oxygenates into high quality gasoline precursors over deactivated ZSM-5 in MTH reaction was successfully demonstrated. The mild acidity of deactivated ZSM-5 in MTH reaction makes a good balance between the high reactivity of different bio-oxygenates and is strong enough for the conversion of bio-oxygenates into high quality gasoline precursors.