Synthesis Of Hydrocarbon Fuel From Fatty Acid Methyl Ester Catalyzed By Metal Modified Porous Silicon Catalyst

Bio-oil is a kind of green and renewable energy.Fatty acid methyl ester is an important component of bio oil.A kind of green hydrocarbon fuel can be prepared by upgrading its quality.This article aims to upgrade the quality of bio-oil to produce green hydrocarbon fuels,methyl palmitate is used as a biomass model compound,and the traditional silicon-based catalysts will be doped and modified by introducing different acid and alkali metals to increase the pore structure,adjust the acid-base and reduce the particle size of the active components.To explore its catalytic hydrogenation and deoxygenation for the preparation of green hydrocarbon fuels carbon-pentadecane and carbon-hexadecane,and to develop practical catalytic application.The details are as follows:(1)One-pot method was used to prepare a silicon-based porous solid Ni/La₂O₃-SiO₂ catalyst in one step for the hydrodeoxygenation reaction of methyl palmitate.XRD,H₂-TPR,NH₃-TPD,(HAADF)-STEM and other characterization analysis was used to investigate the physical and chemical properties of the catalyst,the results show that the addition of La species can significantly change the dispersion degree of Ni species in SiO₂,and La₂O₃ can be produced on or around the Ni species.The embedding effect makes the active compaonent Ni crystal grains smaller,inhibits the agglomeration of the active compaonent Ni,and further imparoves the reaction activity.The investigation of catalytic performance shows that under the conditions of reaction tempaerature of 260?,time of 6 h,hydrogen of 2.6 MPa and catalyst/raw material=1:10,the catalyst has the best hydrodeoxygenation activity and the conversion rate of raw material methyl palmitate at 100%,the maximum yield of hydrocarbon fuel C₁₅ can reach 97.6%.After the catalyst is reused 10 times,the yield of hydrocarbon fuel C₁₅can still reach 90.9%.(2)One-pot method was used to prepare a silicon-based multi-solid Co/Zr O₂-SiO₂ catalyst in one step for the hydrodeoxygenation reaction of methyl palmitate.XRD,H₂-TPR,NH₃-TPD,SEM and other characterization analysis was used to investigate the physical and chemical properties of the catalyst.The Co/SiO₂catalyst is modified by introducing Zr species to form Br?nsted sites,reducing the strong adsorption of Co on activated hydrogen and carbonyl C,accelerating the migration and dissociation of activated hydrogen on the surface of the active center,and inhibiting decarbonylation/carboxyl reaction,Promote C=O bond cleavage and hydrodeoxygenation.The investigation of catalytic performance shows that under the conditions of reaction tempaerature of 300?,time of 6 h,hydrogen pressure of 3.0MPa,catalyst/raw material=1:10,the catalyst has the best hydrodeoxygenation activity,and the conversion rate of methyl palmitate is 100%,the maximum yield of hydrocarbon fuel C₁₆ can reach 96.5%.After the catalyst is reused 5 times,the yield of C₁₆ can still reach 86.3%.In this paper,on the basis of traditional silicon-based catalysts,the silicon-based catalysts are modified by doping with different acid and alkali metals.It is found that the doped alkaline earth metal La is modified to form monoclinic crystal La₂O₂CO₃,and La₂O₂CO₃+C?La₂O₃+2CO reaction occurs.It is beneficial to catalyze the stable decarbonylation reaction of fatty acid esters to obtain carbon pentadecane biofuel products with good repeatability.And acid metals can reduce the strong electron-rich(Zr;Ti etc.)to H and the carbonyl C in the oil molecule C=O adsorption accelerates the migration and dissociation of H on the surface of the active center,which is conducive to the direct hydrodeoxygenation reaction of fatty acid esters to obtain carbon hexadecane biofuel products that are converted with carbon.