Experimental Research On Catalytic Hydrogenation Of Bio-oil Model Compounds

The bio-oil produced by fast pyrolysis of wood has the potential to be used as a substitute for traditional liquid fuel. However, the crude bio-oil appears to be not good in quality just because it’s high water content, instability and corrosion. Study of bio-oil upgrading has performed to improve the quality of bio-oils. This paper conducts a preliminary study on fast pyrolysis of wood and bio-oil refining, which has important practical significance for the sustainable development of the energy.Fast pyrolysis of wood test is conductd in independent research and development of biomass thermal cracking unit. The size, density, humidity of the biomass are analyzed and the physical and chemical properties of the bio-oils are researched. We find that the bio-oil contains a lot of organic material such as acid, phenol, ketones, ester, complicated composition, which resulted in the bio-oil being easy to deteriorate at normal temperature with oxygen existence condition. Therefore, the bio-oil must be further refined.According to research on the modification of bio-oil, the biological oil model compound catalytic hydrogenation unit is established. The model of the core equipment-high pressure reactor is selected and the wall thickness, kettle cover thickness, bolts, stirring shaft, impeller, etc are calculated. The catalytic hydrogenation tests conduct on the bio-oil model compound adjacent 7-hydroxy phenol and methyl acetate and their mixture under the Pd/C catalyst. Through orthogonal test, we get the best reaction conditions of the catalytic hydrogenation reaction, the reaction temperature 280℃, the reaction pressure 12 MPa. the reaction time 6 hours, catalyst 5 g. stirring speed 600 r/min. The conversion rate of adjacent 7-hydroxy phenol can reach to 75%. We obtain the adjacent 7-hydroxy of phenol catalysis hydrogenation reaction mechanism. The main product of adjacent 7-hydroxy phenol catalysis hydrogenation is enolate class and cyclohexan class. The catalytic hydrogenation process which removes the 7-hydroxy could make the product more stable. The main product of acetic acid methyl ester hydrogenation catalyst is linear chains of ethers and ketone, and the carbon chain of production is increased. A mixture of catalysis hydrogenation indicates that interactive reactions don’t happen between reactants.Through the model compounds of bio-oil catalysis hydrogenation test, it is feasible that chemical modification methods transform the bio-oil polar groups (carboxyl, aldehyde) into stable the non-polar groups (alcohol). Catalysis hydrogenation improves the quality of bio-oil efficiently. We put forward and set up biomass thermal cracking and biological oil catalysis hydrogenation joint device being based on the original biomass thermal cracking unit. The hydrogenation, cracking and fractionation of bio-oil are performed further and valuable biomass fuel is obtained. What we designed brings a new way for the use of the biomass energy. All in all, it still has a long way to go that bio-oil replaces the traditional fuel.