Study On Conversion Of Biomass With New Solid Acid Catalysts

Petroleum resources, which are as the blood of modern industrial society, are increasingly exhausted. The living environment in the world is deteriorating due to a lot of the mobil vehicles emission and the greenhouse gas emission. In the past decades, many scientists in the world are finding the alternative energe to resolve the energy problems. Biomass is the only one renewable resource that can be translated to the liquid fuel. The widely utilization of biomass resource, such as to produce biofuel and chemicals, can not only overcome the shortage of the fossil fuel, but also decrease the environment pollution and achieve CO₂ zero emission. Biomass conversion with hydrothermal treatment is one of the most effective method to use biomass in large scale .Catalysts play important role in biomass conversion. Some compounds, such as soluble alkali, acid and salt, have been widely used as catalysts in biomass conversion. However, the major disadvantages using these compounds as catalyst are hard to separate them from reaction mixture and easy to corrode reactors. Solid acid catalysts, which have high catalytic activity, less corrosion to reactors, more convenience in recycle using, easy to separate from reaction systems, are good selection by using in biomass conversion.In this thesis the catalyst of Cl^--Fe₂O₃-La₂O₃/ZrO₂-SiO₂was prepared with supercritical drying and dipping method. The catalysts SO₄^2--Fe₂O₃/MCM-41, SO₄^2--ZrO₂/MCM-41 and MO-MCM-41 were prepared with hydrothermal synthesis and immersion methods respectively.The results of tests showed that, under the reaction conditions: using Cl^--Fe₂O₃-La₂O₃/ZrO₂-SiO₂ as catalyst, rice husk as raw material, the ratio of water to rice husk was 30:1, catalyst dosage was 4 wt.%, temperature was 250℃and reaction time was 2h, the liquefaction yield was 91.9%. The results of lignin conversion with Mo-MCM-41 catalyst showed that, under the reaction conditions: the ratio of glycerin to lignin was 20.1, catalyst dosage was 5wt.%, temperature was 290℃and raction time was 4h, the light oil yield was 52%. The results of lignin conversion with SO₄^2--ZrO₂/MCM-41 catalyst indicted that, under the reaction conditions: the ratio of glycerin to lignin was 20:1, catalyst dosage was 8wt.%, temperature was 290℃and raction time was 3h, the total oil yield was higher. The optimum conversion reaction conditions using SO₄^2--Fe₂O₃/MCM-41 catalyst were 20:1 (glycerin/ lignin), catalyst dosage 8wt.%, temperature 290℃and raction time was 2h , the light oil yield was 41.1%.The results of GC-MS showed that the major productions of rice husk conversion with Cl^--Fe₂O₃-La₂O₃/ZrO₂-SiO₂ catalyst were phenols, cyclopenten-one and methoxy-phenols. The major productions of lignin conversion with Mo-MCM-41 were phenols and esters. The major productions of lignin conversion with SO₄^2--ZrO₂/MCM-41 were 2-methoxy-4-methyl-phenol and 1-Nonadecene. The major productions of lignin conversion using SO₄^2--Fe₂O₃/MCM-41 were Heptadecene, Tetradecene.The catalysts produced in this thesis were characterized by FT-IR, XRD and NH3-TPD. The results of test showed that the chlorine was in the form of ClO₄^-within the Cl^--Fe₂O₃-La₂O₃/ZrO₂-SiO₂ and had two super acid centers on the catalyst surface. In Mo-MCM-41 catalyst it was found one weak acid center and two super acid centers. For SO₄^2--ZrO₂/MCM-41 there were two super acid centers and many weak acid centers. On the surface of SO₄^2--Fe₂O₃/MCM-41 it were had super acid, acid and weak acid centers at same time.