Study On Microwave Thermal Pyrolysis Biomass Oil And Hydrodeoxygenation

With the rapid development of society and the increasing demand for energy,the limitation of non-renewable energy sources has led to a series of problems such as energy shortage and environmental pollution.Therefore,it is particularly important to urgently find renewable energy sources to replace non-renewable energy sources.According to research and investigation,biomass energy has many advantages such as low sulfur,low nitrogen,and more objective storage capacity,so it has attracted much attention.Coconut cloth is a waste of tropical biomass agriculture in Hainan,and its output is relatively large.Therefore,this article chooses local coconut clothe as the raw material,through the research of microwave pyrolysis coconut cloth technology and product property analysis,and then conducts the hydrogenation experiment of model compound(phenol)and real biological oil on the main components of the liquid product,thereby improving quality of liquid products.Using coconut cloth as raw material,microwave pyrolysis was used to convert coconut cloth into biomass oil.The best pyrolysis process was explored through single factor conditions.The test results showed that the best liquid yield conditions were a pyrolysis temperature of 550?,a heating rate of 20?/min,pyrolysis time 25 min and nitrogen flow rate 80 m L/min.Using the Box-Behnken test design,the response surface method was used to optimize the microwave pyrolysis process of coconut coating.Effect of liquid yield.The primary and secondary order of the influence of each factor on the liquid yield is:microwave cracking temperature>nitrogen flow rate>cracking time>heating rate.By GC-MS analysis of bio-oil,the phenol content in the bio-oil was42.99%,and the total phenols content was 79.57%.Synthesis of molecular sieves SAPO-11 and Zr-SBA-15 catalysts,using methanol as a hydrogen-donating solvent,and in-situ hydrodeoxygenation of phenol,it was concluded that SAPO-11 had better catalytic performance,and then the phenol process conditions were investigated to obtain the reaction temperature It is 220?,N₂ pressure is 0.5 MPa,V(water):V(methanol)is 30 m L:10 m L,and the reaction time is 7 h.The maximum conversion rate of phenol is 97.48%.The response conditions were used to optimize the reaction conditions.It was found that the optimal reaction conditions were consistent with the single factor conditions,and the conversion rate was close to the single factor value.Through the investigation of real bio-oil through the best reaction conditions,the bio-phenol content decreased,the alkane content increased by 8.92%,and the bio-oil stability was improved.The imidazole ionic liquid was synthesized and grafted onto molecular sieve Zr-SBA-15(Si/Zr=2,10,40)to obtain catalyst IL/Zr-SBA-15.The supported catalyst was characterized by XRD,SEM,FTIR,and BET.The structure of the later supported catalyst is consistent with that of the original support.Through the investigation of hydrodeoxygenation of phenol,the performance of Si/Zr=10 catalyst is better.Orthogonal experiments are designed using IL/Zr-SBA-15(Si/Zr=10)as the catalyst.The best optimal reaction conditions are obtained.The reaction temperature was 240?,the amount of IL/Zr-SBA-15 was 0.8 g,the hydrogen pressure was 5 MPa,and the reaction time was 4 h,obtain a selectivity of 79.81%for the cycloalkane.The order of influence of reaction conditions on phenol conversion is:reaction temperature>amount of catalyst>hydrogen pressure>reaction time.The best reaction conditions were obtained through the study of phenol.Under this condition,the hydrodeoxygenation of the biomass oil was studied,and the phenol content of the biomass oil was greatly reduced.The normal paraffin content reached 31.66%.This shows that this new catalyst is better for hydrodeoxygenation of real bio-oil.