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异丁烷与丁烯烷基化反应工艺 总被引:8,自引:1,他引:7
讨论了异丁烷与丁烯烷基化反应工艺在清洁燃料生产过程中的地位、作用和发展趋势;简介了目前石油炼制工业中使用的液体酸烷基化工艺;详细介绍了正在研究开发的固体酸烷基化技术;对在烷基化反应中应用的新型固体酸催化材料和新催化反应工艺的探索和进展进行了综述。 相似文献
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The catalytic behavior of the novel MCM-22 zeolite for the continuous alkylation of isobutane with 2-butene has been investigated at a temperature of 50°C, 2.5 MPa total pressure, and a variety of olefin space velocities. At high olefin conversions the MCM-22 zeolite showed a very high initial cracking activity attributable to strong Brønsted acid sites, as well as to the existence of strong diffusional restrictions of the TMP's (formed inside the zeolite) to exit through the channels. At short times on stream (TOS), TMP's account for ca. 40% of the C8 fraction. The olefin conversion and the cracking activity rapidly decline with TOS, while the alkylate product became richer in dimethylhexenes, indicating a predominance of 2-butene dimerization and a loss of hydrogen transfer activity as the catalyst aged. Moreover, MCM-22 gives less TMP's than large-pore zeolites (USY, beta, mordenite), but more than the mediumpore ZSM-5 at similar 2-butene conversion. The latter catalyst was much more selective for olefin dimerization than for isobutane alkylation, presumably because formation of the bulkier TMP's was strongly impeded in its smaller pores. 相似文献
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The disproportionation ofn-butane (and of isobutane) was catalyzed by sulfated zirconium oxide containing 1.5 wt% Fe, 0.5 wt% Mn, and 4.0 wt% sulfate at 2.0 atm and temperatures in the range of 30–60C. The reaction accompanies isomerization, which under some conditions is as much as one or two orders of magnitude faster than disproportionation. The conversion to each of the products increased with time on stream in a flow reactor, and then declined. The time on stream for maximum conversion was the same for each product. The results suggest that the disproportionation and isomerization reactions proceed through a common C8 intermediate. Rates of the disproportionation reaction were determined at the time on stream corresponding to the maximum conversion at each temperature; for example, the rate of conversion ofn-butane into isopentane at 60C with ann-butane partial pressure of 0.58 atm was about 1×10–7 mol/(g of catalyst s). 相似文献
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A highly active superacid of 2 wt% Fe-supported ZrO2 for the skeletal isomerization of butane to isobutane was obtained by sfexposing Fe2O3/ZrO2 to 1 N H2SO4 followed by calcining in air at 700°C for more than 24 h; the Fe2O3/ZrO2 was prepared by impregnating zirconia gel with a solution of Fe(NO3)3 followed by drying at 300°C (2 wt% Fe). A much lower activity was observed with the opposite procedure, where the first impregnation was sulfation of the gel, followed by a second impregnation with the iron compound. It was proved from analysis of the sulfur content in the catalysts that residual sulfur species were not related with generation of the superacidic sites. XPS showed the catalyst to be Fe2O3 supported on ZrO2.Superacids by metal oxides, VIII. For previous publications VI and VII in this series see refs. [10,11]. 相似文献
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Steam reforming of isobutane on a 0.5% Pt–Ce0.8Gd0.2O1.9 catalyst was carried out from 300 to 700 °C under integral conditions with a gas hourly space velocity (GHSV) of 12,000 h−1. The major products were H2, CO2, CO and CH4. The other products produced were ethane, ethylene, propane and propylene with a total molar composition of less than 1.5%.
A complete conversion of isobutane was achieved at 700 °C, Kinetic data was obtained by changing the partial pressure of the
reactants and the temperature under differential conditions with a GHSV of 55,400 h−1. This was done after observing stable isobutane steam reforming for 160 h and under conditions where the mass transfer limitations
were insignificant. An empirical Langmuir–Hinshelwood type model that best fit the kinetic data available was developed. 相似文献
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Clara Comuzzi Giuliano Dolcetti Alessandro Trovarelli Fabrizio Cavani Ferruccio Trifirò Jordi Llorca Richard G. Finke 《Catalysis Letters》1996,36(1-2):75-79
The thermal and structural stability of the Wells-Dawson-type heteropoly compound K6P2W18O62·10H2O was examined by FT-IR spectroscopy, X-ray powder diffraction, thermogravimetric analysis and HRTEM. It was found that calcination at temperatures higher than 850 K led to the formation of a Keggin-type compound K3PW12O40, containing small amounts of an additional phase originated from the high-temperature interaction between potassium phosphate (K3PO4 formed during the decomposition of the K6P2W18O62·10H2O) and the Keggin-type compound itself. The Keggin-type product showed a higher activity in the selective oxidative dehydrogenation of isobutane to isobutene compared to both the Wells-Dawson precursor and to pure, authentic K3PW12O40. This higher activity can be tentatively attributed to the presence of an amorphous layer of unknown stoichiometry at the surface of the thermally rearranged Wells-Dawson compound. 相似文献
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