Study On The Catalytic Deoxidation Of The Vegetable Oil To Bio-Fuels

Petroleum and coal are not renewable. Moreover, the quantity of the crude oil is poorer every day. The rapid growth of the world economy makes the demand of crude oil increasing 26 % every year since 1995. In addition, the environment problems caused by the use of fossil fuels have been more serious. Seeking and developing renewable energy comes to be important to national government. The using of renewable energy sources（RES）, which include hydro energy, wind energy, solar energy, biomass energy, tidal energy and wave energy, is considered to be a solution to energy lacking and the pollution caused by fossil resources in long-term.Biomass is the only renewable energy containing carbon and biomass can be converted to liquid fuels, gas fuels, solid fuels and fine chemicals. Conversion of biomass-derived into hydrocarbon is regarded as a carbon neutral process due to carbon-cycling between chemical conversion（Biomass â†' hydrocarbon + CO₂）and photosynthesis（light + CO₂ + H₂Oâ†'Biomass）,so bio-fuels can be considered to zero net emission of CO₂. Comparing to fossil fuel, biomass contain less of sulfur and nitrogen, so the content of sulfur and nitrogen is less in bio-fuels, which gives lower emissions of SO₂ and NOx. The first generation bio-fuels are called fatty acid methyl ester（FAME） which can be produced by ester exchange technologies. Comparing to petroleum fuel, FAME has many physical-chemical disadvantages, such as higher cloud point, higher viscosity, freezing point, pour point and etc, especially the poor oxidation stability. The most viable way forward is to deoxidization of triglyceride to Non-ester renewable diesel（NERD）, which is called second generation bio-fuels.In the paper, researches filter a lot of material and finally use γ-Al₂O₃ as carrier and V20, Co20 and Ni20 as activity center to producing more effective double metal catalysts promoted by using Ce, with impregnation method. The catalysts were characterized by XRD, BET, H₂-TPD and H₂-TPR, and detect catalyst activity by fixed bed unit and WFSM-3060 high-pressure reactor.The results revealed that the V20 and Co20 catalyst had the good activity in the deoxidization. The oxygenated compound contents were 11.3 % and 11.4 % in the liquid product produced the V20 and Co20 catalyst. The V20 catalyst was the best in the activity of the hydrogenation reaction and the alkane content of liquid products produced V20 catalyst was 41.1 %.The synergic effect was produced in the process of catalyst preparation between nickel nitrate and cobalt nitrate species. The oxygenated compound content produced 15Co5 Ni catalyst was the lowest（3.4 %）. The results revealed that the adding of cerium played an important role in the deoxidization, the hydrogenation and reducing coke.Researchers investigated the reaction conditions of triglycerides to NERD. These conditions include reaction temperature, ingredients of catalyst, reaction pressure, gas speed in reaction, oil speed in reaction and etc. The result showed that reaction temperature is the key factor for NERD, ingredients of catalyst and oil speed also have large impact on reaction and gas speed is less influential. Liquid outcome are analyzed by FT-IR,SF-3 and GC-MS, and gas outcome is analyzed by GC online. Researches also investigated the producing condition of renewable bio-fuels which is made from the deoxidization of the crude oil. There good reaction conditions are found in the research and show blow: the first, 15Co5Ni/γ-Al₂O₃ catalyst in normal pressure. The condition is that reaction temperature is 450°C, the proportion of Ni and Co in catalyst is 3:1, gas speed is 12 mL/min and oil speed is 0.1 m L/min. Under the optimal condition, the yield of liquid production, the content of oxygenated compounds and the coke rate are: 85.8 wt %, 3.3 wt % and 2.1 wt%, respectively. The content of alkanes and alkenes in liquid are 44.9 % and 49.1 %, respectively; the second, 15Co5Ni-10Ce/γ-Al₂O₃ catalyst in high pressure. The condition is that reaction temperature is 450°C, reaction pressure is 3.0 MPa, gas speed is 35 mL/min and oil speed is 0.1mL/min. Under this condition, the yield of liquid production, the content of oxygenated compounds and the coking rate are: 87.1 wt%, 2.3 wt% and 1.0 wt%. The content of alkanes and alkenes in liquid are 50.8 % and 41.9 %. The third, 10VNi-10Ce/ γ-Al₂O₃ catalyst in high pressure. The condition is that reaction temperature is 450°C, reaction pressure is 3.0 MPa, gas speed is 30 m L/min and oil speed is 0.1 mL/min. Under this condition, the yield of liquid production, the content of oxygenated compounds and the coking rate are: 86.9 wt %, 3.0 wt % and 1.2 wt %. The content of alkanes and alkenes in liquid product are 60.0 % and 29.2 %.Most of alkanes and alkenes are hydrocarbons under C18 and the main products are hydrocarbons of C11 C17. According to the results of GC online analysis and SF-3 analysis, the deoxidization in the crude oil is mainly by decarbonylation reaction and decarboxylation reaction which are happened in the same time, and small part is by water generating. Moreover, the decarboxylation reaction is the main reaction. From the results of FT-IR,SF-3 and GC-MS, researchers deduced the generating mechanism of NERD.The conversion from plant oil to bio-fuels were investigated in the paper, and give a theory base to solving energy lacking and greenhouse problem by using bio-fuels and also provide a scientific experimental data to other researchers.