Biomass-oil Upgraded By Catalytic Hydrogenation Of Molybdenum Disulfide And Its Thermal Behaviour

Biomass-oil has been regarded as green and renewable energy and paid moreattention. However, it has not been applied in engine as fuel till now because of itspoor physicochemical and thermal performance. The effects of molybdenumdisulfide particles with different sizes on the catalytic hydrogenation of biomass-oilwere studied in the present thesis in order to improve the physical and chemicalproperties of biomass-oil. At the same time, it was also investigated the thermalbehaviours of the final catalytic hydrogenated biomass-oils. More detailedresearches were summarized as follows.1. Firstly, aiming at the local incomplete combustion and leave the solidproduct of oils, the final combustion products of biomass-oil were studied bymeans of X-ray diffraction (XRD), transmission electron microscopy (TEM), X-rayphotoelectron Spectroscopy (XPS) and thermogravimetry (TG) respectively. Theexperimental results showed that the weight of final combustion product was about6.55%that of biomass-oil. The main composition of the final combustion productwas amorphous carbon with irregular shape. In addition, the combustion productcould be burned further to ash under oxygen.2. Then, both microsized molybdenum disulfide particles (micro-MoS2) andnanosized molybdenum disulfide particles (nano-MoS2) were selected as catalystsfor the catalytic hydrogenation of biomass-oil respectively. And the effects of thecatalytic hydrogenation were investigated by the comparison of following aspects:yield and physicochemical properties of upgraded oil, H/C ratio and so on.Meanwhile, the experimental results were also compared with those of Pd/C whichwas proved to be a good catalyst in hydrogenation. In addition, both Fouriertransform infrared spectroscopy (FTIR) and ultravoilet spectrometer (UV) werealso used to analyze the changes of function groups before and after catalyticreactions. The results indicated that the nano-MoS2had better hydrogenation effectat250℃. However, it was showed that the micro-MoS2had the betterhydrogenation effect at350℃. The micro-MoS2was proved to be a better catalystaccording to cost, hydrogenation effect and so on. Especially, the micro-MoS2would be helpful in the elimination of unsaturated bonds in some functional groupsin the biomass-oil. 3. The distillation process was used to separate the light fractions from thebiomass-oil with the help of glycerin. The yield of light fractions was about55.7wt%. The hydrogenation reactions were token place at150℃,250℃,350℃and150/350℃respectively. It was compared the yields and physicochemicalproperties of upgraded oils and H/C ratios at different temperatures. Both FTIRand UV were also used to analyze the structure changes of function groups beforeand after catalytic reactions. The experiment results showed that high temperaturewas beneficial for the catalytic hydrogenation with micro-MoS2, and the optimalresult was obtained by two steps of catalytic hydrogenation at150/350℃successively.4. Finally, the thermal gravimetric analysis was to study the thermalbehaviours of the biomass-oil, the light fractions of biomass-oil and variousupgraded oils. At the same time, the each process of reactions was simulated byway of first order dynamical equation. The results showed that the activity ofupgraded oil was improved via hydrogenation process. Especially, it was showedthe best effect for micro-MoS2by two steps of catalytic hydrogenation at150and350℃successively.