| Nowadays, the gradual depletion of fossil fuels and gradual expansion ofenvironmental hazards had lead to many countries pay much attention on developingbiomass to fuels and chemicals. Biomass platform compounds not only can bedirectly used as fuels or fuel additives, but also can be further converted to highoctane gasoline and various chemicals. Therefore, conversion of biomass platformcompound GVL into fuels and valuable chemicals has an important theoretical andpractical significance for the development of biomass.In this study, preparation of high octane number gasoline over catalysis methodwith biomass platform compound GVL as raw materials. Primarily conversion ofGVL into butenes with mesoporous SiO2-Al2O3as the catalyst，and then alkylationbetween butenes and isobutane into high octane number gasoline withBF32CF3CH2OH coordinated complex as the catalyst.:(1) The study of conversion of biomass platform compound GVL into butenesA series of SiO2-Al2O3molecular sieve catalysts with different Si and Al molarratios were prepared by sol–gel method and systematically characterized by TG, XRD,BET, Pyridine-FTIR and SEM. it is shown that SiO2-Al2O3catalysts are large surfacearea mesoporous structure, both different amount Br nsted and Lewis acid are on thesurface of SiO2-Al2O3catalysts, with the increase of the molar ratio of Si and Al,Br nsted acid sites gradually increase and Lewis acid sites decline slowly， the totalamount of acid catalyst also gradually decline. The influence of various Si and Almolar ratios SiO2-Al2O3catalysts on conversion of GVL to butenes were investigated,Due to SiO2-Al2O3catalysts (molar ratio of4:1) has a large amount of Br nsted acidsites and little of Lewis acid sites exhibited the highest catalytic activity andselectivity.The reaction temperature, time, pressure, and catalyst content were investigated.The optimum reaction conditions for conversion of the GVL to butenes are as follows:the highest conversion of GVL and highest yield of butenes (97%) achieved after4hat350oC over5wt%of SA-4:1catalyst. Maintain while， there was almost no significant decrease in conversion of the GVL to butenes within30h by evaluation ina fixed-bed reactor. Furthermore, consider molecular structure of GVL andcharacterizations of catalysts, a mechanism for the decarbonylation of GVL intobutenes was proposed and verified: γ-valerolactone open-loop into pentenoic acid,and then pentenoic acid cleave into butene and carbon dioxide under the action ofLewis and Br nsted acid on catalyst surface.(2) The study of butenes and isobutane alkylation into high-octane gasolineIsobutane-butene alkylation reaction with synthesized BF32CF3CH2OH as thecatalysts achieve high-octane gasoline. Effect of different temperature and time onisobutane and butene alkylation reaction was investigated. the optimum conditionsalkylation reaction are as follows: isobutene/butene feed ratio10:1, at10℃, after10min, the conversion of butene is more than99%, the highest yield of C8fraction82.47%, which Trimethyl pentane (TMP)72.89%, two methyl hexane (DMH)12.87%, octane number of gasoline RON95.4, MON93.4, the key properties ofgasoline can meet the specifications of EN228.Meanwhile, the regeneration cycles of catalyst was investigated, it is shown thatthe catalyst showed similar performance in the first6reactions and the catalyst usedsix times still exhibit good catalytic activity. In addition, BF32CF3CH2OH acidcatalyzed isobutane and butene alkylation reaction mechanism were discussed. Firstof all, Butene reacts with H+to form i-C4+cation, which further reacts with butaneand forms i-C8+cation as the intermediate. In the presence of isobatane, its hydride isabstracted by i-C8+cation and forms i-C4+cation, which keeps the catalytic cyclegoing. |
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