小晶粒ZSM-22的可控合成及其催化长链正构生物烷烃制航空煤油性能

由生物脱氧油制生物航空煤油具有较大应用潜力和发展前景，为了提高生物航煤的收率，开发性能更好的加氢裂化/异构化催化剂是关键。本文采用水热合成法，在低温陈化、加入晶种、提高合成凝胶的碱度或加入有机碱条件下，合成了平均c轴尺寸在100~330nm的小晶粒ZSM-22分子筛，进行了XRD、SEM、N₂物理吸附、NH₃-TPD和吡啶红外表征，并以生物质油加氢脱氧得到的长链正构生物烷烃为原料，考察了不同晶粒尺寸 ZSM-22催化剂催化裂化和异构化制生物航空煤油的性能。结果表明，通过提高碱度合成的小晶粒H-ZSM-22 具有较强的酸中心，较多可及的强B酸中心数量，其长链正构烷烃转化率可达80%以上。在此基础上，制备的Pt/ZSM-22催化剂具有较高的Pt分散度，表现出很好的加氢裂化/异构化性能，其长链正构烷烃的转化率高达97.79%，生物航煤收率达50.25%，航煤产物异正比为7.55。

Controllable synthesis of small size ZSM-22 zeolites and their performance in the production of bio-jet fuel by hydrocracking and hydroisomerization of long-chain normal bio-paraffins

The production of bio-jet fuel from biological deoxygenated oil has great application potential and development prospects. To improve the yield of bio-jet fuel, it is essential to develop high-performance catalysts for the hydrocracking and hydroisomerization. After low-temperature aging, adding seeds or increasing the alkalinity of the initial gel and crystallization, small size ZSM-22 zeolites were obtained with the average c-axis size between 100—330nm. The samples were characterized by XRD, SEM, N₂ physical adsorption, NH₃-TPD and Py-IR. Catalysts prepared by ZSM-22 with different crystal sizes were evaluated on the cracking and isomerization of long-chain normal bio-paraffins from hydrodeoxygenated biomass oil to bio-jet fuel. The results indicated that, the small crystal size H-ZSM-22 synthesized by increasing alkalinity of gel had stronger acid centers and more accessible strong B acid centers. The conversion of long-chain normal bio-paraffins were more than 80%. Further, the Pt/ZSM-22 catalyst possessed high Pt dispersion and exhibited great hydrocracking and isomerization performance. The conversion reached 97.79%, and the yield of bio-jet fuel was as high as 50.25% with an iso/n-paraffin ratio of 7.55.