Research On Catalytic Esterification-Hydrogenation Process Of Bio-oil On Different Pathways Over Moraney Ni Catalyst

Bio-mass has attracted much attention as a renewable alternative to fossil fuels for its increasing consumption and rising environmental problems.However,properties such as complex oxygen-rich chemicals,high viscosity,low PH,corrosiveness,limit its widely usage.Based on the high acidity and instability of crude bio-oil,we conducted this paper firstly to study the interactions between acids and phenol with methanol as solvent.Secondly,added in ketone,aldehyde and furans into this acidphenol system gradually,to investigate the interactions between the typical compounds exist in bio-oil.On the above results,we proposed the second hydrogenation of the first upgraded oil over Ru/C catalyst.And then,applied this twice hydrogenation method to the real bio-oil upgrading process,which providing a new thought to solve the problem of bio-oil refining.Selecting the Mo modified Raney Ni as catalyst,added phenol and different acids into the methanol solvent to understand the interactions between acids and phenol.Then we detected the effect of reaction parameters,including temperature and pressure,on conversion,selection and H2 consumption of the acids and phenol esterificationhydrogenation products.Results show that acid and phenol restrained the hydrogenation process of each other.What's more,reaction temperature and pressure had a great effluence on their hydrogenation,and the optimal reaction were obtained under 180 ? and 2MPa H2 pressure with the highest alcohol and ester content.In addition,there was a good balance between the Actual consumption theoretical demand of H2,rate of waste were all limited in 4%.To better explain the reactions between the complex components in bio-oil,model bio-oil system were achieved through added in ketone,aldehyde and furans into the acid-phenol system gradually,to study the reaction effect of each added component.And then different additive amount of hydroxy-acetone and furan were also studied.Except that,second hydrogenation over Ru/C catalyst were also conducted over the upgraded model bio-oil,and the characterization of catalysts were detected.Results indicated that upgraded products were mainly liquid phase,meanwhile,hydroxyacetone,furan and furfural could be converted absolutely under each condition.While adding in the second and third components,the selection of alcohols in the products decreased,as well as the phenol conversion.When reduced the added amount of hydroxy-acetone and furan to 1/3*0.01 mol,the effect of hydrogenation was consistent with the real bio-oil system.Catalyst characterization results showed there were slightly carbon deposit and coking occurred during the reactions,reflected in the SEM and XRD results.For the real bio-oil upgrading process,we carried out 3 esterifcationhydrogenation methods aiming at achieving high alcohol and ester content bio-fuel,then we tried to explain the reaction pathways of the typical components of bio-oil.Through the onestep or separated esterification-hydrogenation process,bio-oil got substaintially improve.While the best oil quality were obtained through the following second hydrogenation over Ru/C catalyst,for the unreacted esters,ketones and other oxygenous compounds were further hydrogenated,which resulted in an alcohol and ester content of 84.20%.