Research On Direct Deoxy-liquefy Biomass Of Forest To Obtain Fuel And Phenolics Compounds

Biomasses were renewable oxygen-containing fuel. If it was converted and applied in internal combustion engine, not only reduce the dependence of automobile industry on petroleum, but also slow down the emissions of CO₂ greenhouse gases. The pyrolysis liquids from biomass also called bio-oil were obtained through the traditional pyrolysis process. And the oxygen content in it was usually 35-45% which existed in the form of water and other forms such as aldehydes, ketones, sugars, carboxylic acids, phenols. The existence of these substances made it difficult for the bio-oil in place of the traditional fossil fuels. Our research group has developed an innovative technological route in which biomass can be converted into the carbon-hydrogen liquid fuel with high heating value by direct deoxy-liquefaction in the absence of hydrogen. The detailed studies were as follow:Under certain conditions, 18 kinds of samples were experimented. Results showed that oils from the leaves rich in alkanes and aromatics. The total content of alkanes and aromatics were up to 60.01% 57.86% for poplar leaves and birch leaves with H/C molar ratio 1.79 and 1.89, O/C molar ratio 0.035 and 0.036, and HHV 45.47 MJ·kg^-1and 46.03 MJ·kg^-1These data shows that the oil from leaves was very similar to petroleum. The hydrocarbon content in oil from bark were decreased and then the HHV about 40 MJ·kg^-1A large number of phenolics were found and the content was up to about 40%. The oil obtained from wood was rich in phenolics but poor in hydrocarbons. The kind of phenolics was about 30 species, and the total content of them were up to 60%. The oil obtained from grass was similar to that of leaves but the inadequacies of the oil was large amounts of nitrogen-containing compounds were found, which was difficult to refined.Among the poplar leaf, bark and wood, the poplar leaf rich in surfactant extract, while extracts in poplar wood was poor. On the contrary, lignin content was very high in poplar wood but poor in poplar leaves. As for product distribution, the oil yield of leaves was higher than that of poplar bark and poplar wood. In regard to the composition of gas product, gas from leaves contain more oxygen and less hydrogen element. For the gas from poplar bark and wood, the oxygen contained in gradually reducing and hydrogen elements in the progressive rise. The increase of oxygen content in gas can reduce the oxygen content in the oil. The oil from leaves contains a large number of hydrocarbons and contains small amounts of phenolics but oil from poplar wood contains a lot of phenolics and little hydrocarbons. The bark was moderate. Therefore we can conclude: more surfactant extract contained in raw materials more hydrocarbon content in oil.In summary, forestry biomass can not only be converted to gasoline and diesel, but also to phenolics by direct deoxy-liquefaction method. Leaves and grass were suitable converted to gasoline and diesel. Bark and wood were suitable converted to phenolics by direct deoxy-liquefaction.