Liquid Phase Catalytic Hydrodeoxygenation Of Model Compounds Of Bio-oil To Prepare Liquid Fuel

Biomass is the only carbon resource in renewable energy that can produce petroleum substitutes.The bio-oil produced by pyrolysis of biomass has high application value,while it has high oxygen content and poor stability greatly reduces its utilization value.Therefore,further hydrodeoxygenation(HDO)of bio-oil to prepare available fuel has been widely researched.However,there are unclear in the interaction mechanism and the reaction path of many different types of model compounds in bio-oil in the HDO process,and the catalyst economy is poor.Based on the above reasons,this paper mainly includes the following aspects:(1)In this study,HZSM-5,Al-SBA-15 and Al-SBA-15/HZSM-5 were selected as microporous,mesoporous and micromesoporous supporting materials for nickel-based catalysts.A series of Ni-based composite catalysts were synthesized and their surface modifications were optimized.Py-FTIR,TEM,XRD,XPS and other analytical methods were used to study the composition of functional groups,acidity,acid content and pore structure on the surface of the catalyst.The effect of catalyst composition on HDO was studied.It was identified that Ni/Al-SBA-15/HZSM-5 was a micromesoporous catalyst for HDO of eugenol with high efficiency.(2)Four common substances were selected as solvents to investigate the effects of the properties of different solvents on the catalytic HDO of eugenol.The optimum solvent volume and single solvent were selected by using mixed solvent with different solvent volume and different proportion of ethanol.The experimental results show that n-dodecane is the best single solvent.In ethanol mixed with different solvents,50 m L is the most suitable volume.In the mixed solvent,with the increase of ethanol,the conversion of eugenol tends to be simple phenolic substances such as 4-methylphenol.(3)Further explored the impact of light fraction components in bio-oils on the conversion of phenols,clarified the conversion path of phenol-light molecular coupling HDO reactions and explored possible intermolecular interactions,including the active site competition.The main conversion pathways of eugenol and acetic acid,ethylene glycol and furfural in HDO were deduced.The experimental results show that mixing eugenol with light fraction as a reactant can reduce the ring-breaking reaction in the HDO process.After adding acetic acid,ethylene glycol and furfural into the reactants,it was found that acetic acid would reduce the catalytic activity of Ni/Al-SBA-15/HZSM-5,and the effect was more pronounced with higher acetic acid content.However,the addition of ethylene glycol to the reactants did not significantly affect the selectivity of alkanes.After mixing furfural and eugenol,the selectivity of propyl-cyclohexane decreased obviously.When the furfural content increased to 3%,the selectivity of 2-methoxy-4-propylphenol increased to 73.7%,and the selectivity to alkanes decreased to 17.4%.