Study On The Direct Liquefaction Of Paulownia In Water With Fe As Catalyst

To solve the energy crisis caused by the shortage of oil and environmental pollution problems caused by the use of fossil fuels, many researchers start to research on this clean renewable energy source. Bio-mass is one clean renewable energy source which only can transform into the liquid fuel, and can be stored and carried, direct liquefaction technology that can make biomass transform into liquid fuel is relatively mild reaction conditions, relatively low demands on the equipment, and easy to be used in industrial production. Among many liquefied biomass mediums, water is the cheapest, non-toxic, harmless, and do not pollute the environment, and those are reasons why it is great significance to research on and develop direct liquefaction technology in water.In this research, we made study on catalytic liquefaction of paulownia in water in an 1L autoclave, and paulownia that originated in China, widely distributed, easily reproduced, and was a large quantity of cheap trees with fast-growing was raw materials, the water was used as a reaction medium and the Fe was used as a catalyst. When paulownia was 60g, the water was 360ml, and the stirring speed was 300r/min, the experiment revealed influence of reaction temperature, holding time and dosage of catalyst on the yield of bio-oil, the yield of solid residues, and the composition of gas products, analyzed the character of the composition of bio-oil, determined the distribution of iron catalyst in the liquid phase and residues to provide the basic data for the future of industrial production.When the temperature was among 280℃-360℃, the holding time was among 10min-50min, and the dosage of catalyst was among 0g-12g, the experiment revealed influence of different conditions, the results showed that with the temperature raising the yield of bio-oil increased after the first lower , and the yield of residue reduced after the first increasing. With the holding time longer the yield of bio-oil declined, and the yield of residue increased. With the dosage of catalyst increasing the yield of bio-oil increased, and the yield of residue declined, but when the dosage of catalyst was above 10wt%, the increasing of the yield of bio-oil and the declining of the yield of residue was not obvious. So the better reaction conditions were that the temperature was among 320℃-360℃, the holding time was among 10min-30min, the dosage of catalyst was 6g, the yield of heavy oil was about 35%, total oil was about 50%, and the yield of residue was about 13%.Bio-oil obtained by liquefaction was a black ropy liquid with highly acidic. The bio-oil was analyzed with infrared spectral, and investigated the type of organic matter of liquefaction products of biomass, according to absorption peak position of the degree of bio-oil, which was found that the bio-oil which was produced by our experiment was, and had complex component, including fats, aromatic, organic acid, aldehyde, ketone, alcohol, phenol, ether, ester etc.Gas products at different reaction conditions was analyzed by gas chromatography, we found that gas products were mainly composed of carbon dioxide, carbon monoxide, and methane, under the reaction conditions of the higher yield of bio-oil and the lower yield of residue, when the temperature was among 320℃-340℃, the holding time was among 10min-30min, the dosage of catalyst was 6g, the proportion of CO₂ was above 80%, the proportion of CO was less than 80%, and the proportion of CH4 was about 1 %.The content of iron in liquid phase and solid residue after liquefaction at different reaction conditions was analyzed with UV-spectrophotometer, The results revealed that little iron exist in liquid phase, and mainly in the form of Fe²⁺; a great deal of iron existed in solid residue, in which the content of Fe was the largest about 60%, Fe⁰ was the second content about 30%, Fe³⁺ was the least.