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Reducing Olefins in FCC Gasoline by Isomerization and Aromatization over Modified Nano-ZSM-5

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催化学报 2003年第3期24卷 159-160页

作者： ZHANGPeiqing wangxiangsheng 等 StateKeyLaboratoryofFineChemicalsandInstituteofIndustrialCatalysts DalianUniversityofTechnologyDalian116012LiaoningChina StateKeyLaboratoryofFineChemicalsandInstituteofIndustrialCatalysts DalianUni

The rapid development of automobile and the greatly increased consumption of fuel have caused more and more serious air-pollution by the emission of tail gas~[1,2]. To reduce the emission of tail gas from gasoline-powered engines, governments all over the world have tightened regulations on the composition of gasoline and required the production and use of clean fuels via the reduction of sulfur and olefins in gasoline. A new standard of the composition of gasoline will soon become effective in our country in which the content of olefins must be under 35%(volume fraction, the same below)~[3]. However, approximately 80% of gasoline used in our country comes from FCC gasoline which contains olefins more than 50%. To decrease the content of olefins in gasoline, several measures have been developed, such as optimization of the FCC process, use of new FCC catalysts (GOR, LBO, RFG),hydrogenation, and so on. But the degree of reduction of olefins is not high(only by 6%-13%), and always accompanied by octane value decreasing. Therefore, it is urgent to develop a novel technique that can maintain the octane value while reducing the olefins in gasoline.

关键词：纳米分子筛 ZSM-5 催化剂 FCC汽油烯烃芳构化异构化

Synthesis of Titanium Silicalite-1 in the Presence of Tween 40

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催化学报 2003年第3期24卷 161-162页

作者： WANGLiqin wangxiangsheng 等 DepartmentofChemicalEngineering QiqiharUniversityQiqihar161006HeilongjiangChina StateKeyLaboratoryofFineChemicals DepartmentofCatalyticChemistryandEngineeringDalianUniversityofT

Traditionally, the hydrothermal synthesis of titanium silicalite-1 (TS-1) needs a large amount of tetrapropyl ammonium hydroxide (TPAOH) as a template(n(TPAOH)/n(SiO_2)=0.4-1.0), and the crystallization time takes 10-30d~[1]. Recently, much attention has beenpaid to the modification of synthesis methods, and many improvements have been made~[2-7]. In this work, a new method was developed to synthesize nanometer-sized TS-1 in the presence of Tween 40 as surfactant, which is based on using a non-ionic surfactant to decrease the surfacetension of solution and to iduce the orientation of the template molecules~[8]. Using this method, the n(TPAOH)/n(SiO_2) can be decreased to 0.1-0.2, so the synthesis cost of TS-1 is less. Furthermore, the synthesis time can be shortened to 24h, the amount of anatase TiO_2 is reduced and the crystal size of TS-1 is more uniform. The synthesized TS-1 samples show excellent catalytic performance.

关键词：吐温40 钛硅分子筛合成催化剂

Shape-Selective Synthesis of 4,4′-Dimethylbiphenyl over Hydrothermally Treated HZSM-5 Catalysts

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催化学报 2003年第9期24卷 647-648页

作者： GUOXinwen wangxiangsheng SHENJianping SONGChunshan StateKeyLaboratoryofFineChemicals DalianUniversityofTechnologyDalian116012LiaoningChina DepartmentofEnergy~zndGeo-EnvironmentalEngineering ThePennsylvaniaStateUniversity209AcadeTnicProjectsBuildingUniversityParkPA16802USA

The shape-selective alkylation of polycyclic hydrocarbons is used to synthesize symmetric intermediates such as 4, 4'-dialkylbiphenyl (4, 4'-DABP) and 2, 6-dialkylnaphthalene (2, 6-DAN) which are important precursors of advanced polymer materials~[1]. The alkylation to prepare 4, 4'-DABP can be carried out using either a large group like isopropyl or a small group such as ethyl or methyl. However, it is difficult to selectively obtain 4, 4'-dimethylbiphenyl (4, 4'-DMBP) through the methylation of biphenyl (BP) and its derivatives~[2,3]. Recently, a break-thorough in the methylation of 4-methylbiphenyl (4-MBP) with methylation of 4,4'-DMBP was as high as 65% over HZSM-5 modified with inorganic P compounds and 80% over MgO-modified HZSM-5. However, the catalyst activity decreased with time on stream due to the formation of coke. it is known that hydrothermal treatment can remove framework aluminum from a zeolite and modified its properties. Catalysts modified in this way show improved stability as well as increased p-selectivity ~[6] in the alkylation of aromatics. This work reports the methylation of 4-MBP with methanol over hydrothermally treated HZSM-5.

关键词：水热处理 HZSM-5 分子筛催化剂择形催化合成 4,4′-二甲基联苯