Study On The Preparation Of Multiaperture Cu Based Catalysts And Oil Hydrodeoxygenation Technology

At a time of rapid economic and social development,the demand for fossil resources is increasing,and the resulting problems of fossil resource scarcity and environmental pollution are becoming more and more serious.Biodiesel is a kind of renewable energy that can replace traditional fossil energy and is of great significance in solving problems such as energy shortage and environmental pollution.Currently,most of the high quality biodiesel uses catalytic hydrogenation technology,and the development of high efficiency catalysts is its core.This thesis studied the physicochemical properties of the prepared Cu based catalysts though XRD,BET,H₂-TPR,H₂-TPD,and CO₂-TPD characterization techniques,and evaluated the catalytic hydrodeoxygenation（HDO）performance over the prepared Cu based catalysts.The following conclusions are mainly obtained:1.The additive and calcination temperature significantly affect the pore structure of the prepared catalyst,the composition and the dispersion of metal Cu species.The filling effect of the Al₂O₃resulted in the average pore size of the prepared catalyst to be decreased.And the crystal size of the metal Cu species showed"V type"variation trend with the increasing of the Al₂O₃introduction amount.High temperature calcination resulted in the structural reorganization of the support,which was easy to form Cu Al₂O₄and was not conducive to the formation of the reactive sites.The Cu/γ-Al₂O₃catalyst prepared by the Al₂O₃introduction amount of 5.0 wt%and the calcination temperature of 500°C showed the minimum metal Cu crystal size（18.2 nm）and showed the best HDO performance.At the reaction temperature of 400°C and the reaction pressure of2.0 MPa,the methyl laurate conversion and the C₁₂alkane selectivity were 77.9%and82.8%,respectively.2.The modification of the acid and basic metal oxides had significant impacts on the alkaline centers,the composition and the crystal size of the metal Cu species over the catalysts.The a large number of moderately strong alkaline sites were formed in the10C/5Ce O-A,10C/5La O-A and 10C/5Mg O-A catalysts,which was not conducive for the metal Cu species to be highly dispersed.Thus,the deep hydrogenation of methyl laurate was inhibited and produced a large number of oxygen-containing intermediates.The weak alkaline sites were formed in the prepared 10C/5Zr O-A,10C/5Al O-A,and10C/5In O-A catalysts modified by Zr O₂,Al₂O₃,and In₂O₃additives,which could effectively inhibit the breaking of the C-C bonds and improve the use stability of the corresponding catalysts.At the same time,the synergistic effect between the metal Cu reactive centers and the acid/basic sites could significantly improve the HDO performance for methyl laurate and the hydrogenation depth over the studied catalysts.Under the conditions of the reaction temperature of 400°C and the reaction pressure of2.0 MPa,methyl laurate conversion over the 10C/5Zr O-A,10C/5Al O-A,and10C/5In O-A catalysts were 77.5,81.1,and 89.6%,respectively.And the C₁₂alkane selectivity over the 10C/5Zr O-A,10C/5Al O-A,and 10C/5In O-A catalysts was 87.7,83.8,and 77.2%,respectively.3.The H₃BO₃additive could significantly affect the distribution and crystal size of the metal Cu species.The number of highly dispersed metal Cu species showed"volcanic"variation trend with the increasing of the additives introduction amount.The appropriate addition of H₃BO₃additives could promote the uniform dispersion of metal Cu species,which was conducive for the reactive crystal surface to be exposed and significantly improved the supply capacity of reactive H species.Under the conditions of the reaction temperature of 400°C and the reaction pressure of 2.0 MPa,the methyl laurate conversion and the C₁₂alkane selectivity over 5C/1B-A catalyst reached 91.3and 83.0%,respectively.The HDO performance over the 5C/1B-A catalyst were significantly superior than the mesoporous Cu/γ-Al₂O₃catalyst with the metal Cu load amount of 10.0 wt%.