DESIGN OF THE CATALYSTS CONTAINING BOTH MICROPOROUS ZEOLITE AND MESOPOROUS MATERIALS FOR THE HYDROREFINING OF GASOLINE AND DIESEL FUEL

摘要

(1) Several novel micro-mesoporous composite materialsrnincluding L(M-L), L-MC[3], L-KIT-6 (LK)[4] were synthesized byrnthe self-assembly of zeolite L nanocrystal clusters in the presence ofrnmesoporous template Triton X 100,CTAB and P123, respectively.rnThe characterization results demonstrated that these materialsrnpossessed relatively high acid amount and acid strength, appropriaternacid types, and a composite pore structure with micropores andrnmesopores.rn(2) The above as-prepared meso-microporous materials werernused as supports to prepare the catalysts for the refining of gasoline.rnCompared with the catalysts introduced conventional microporousrnzeolite L or mesoporous Al-MSU-2 and used bare alumina asrnsupport, the catalysts containing mesoporous zeolite L showed thernexcellent performances of deep desulfurization, aromatization, isomerization and preserving RON value for the hydrodesulfurizationrnreaction of full-range FCC gasoline.rn(3) Micro-mesoporous composite material Beta-KIT-6 (BK) withrnthe BEA microporous structure and cubic Ia3d mesoporous structurernwas synthesized, and used as the catalyst support for thernhydrodesulfurization (HDS) of dibenzothiophene (DBT). Therncomposite material possessed both KIT-6 and Beta structures.rnNiMo/BK had similar acidity as NiMo/Beta, and possessed morernacid sites and stronger acidity than NiMo/KIT-6 and NiMo/SBA-15.rnNiMo/BK showed the highest DBT HDS activity among all therncatalysts that were studied, and the DBT conversion on NiMo/BKrnwas about 2 to 3 times that of NiMo/Al_2O_3. The acidity of NiMo/BKrnenhanced the activity of direct desulfurization (DDS) morernsignificantly than that of the hydrogenation (HYD) pathway.rnCyclohexen-1-yl-benzene was detected as the necessary intermediaternof the HYD pathway[5].rn(4) A new composite material ZSM-5/KIT-6 (ZK-W) wasrnsynthesized by enwrapping nano-sized ZSM-5 zeolite crystals withrnmesoporous KIT-6 silica. This composite was used as catalystrnsupport for NiMo sulfide in the hydrodesulfurization (HDS) of 4,6-rndimethyldibenzothiophene (4,6-DMDBT). The NiMo/ZK-W catalystrngave the highest HDS activity and its 4,6-DMDBT conversion wasrnabout double that of a conventional NiMo/Al_2O_3. The two isomers ofrn4,6-DMDBT (3,6-DMDBT and 3,7-DMDBT), were identifiedrnsimultaneously for the first time in the HDS products of 4,6-DMDBTrnover the NiMo/ZK-W catalyst. The NiMo/ZK-W catalyst exhibited arnsuperior isomerization ability, and 4,4’-dimethylbiphenyl was thernmain product. A new reaction network of 4,6-DMDBT HDS overrnNiMo/ZK-W catalyst was proposed[6].