Catalytic Pyrolysis Of Cyanobacteria With MCM-41 Zeolite Supported Layered Double Oxide

With the development of human civilization,the consumption and demand of energy is growing.And the traditional fossil energy is dimishing and the environmental pollution caused by the utilization of fossil is becoming serious.Therefore,the application of biomass energy has attracted researchers'attention.Due to the advantages of algae biomass,such as high growth rate,no competition with cultivated crops and extensive resources,it was considered as a clean,environment-frendly renewable energy and more researchers are exploring the utilization of algae resource.In this thesis,the catalytic pyrolysis of green algae was operated in self-made fixed-bed reactor.And different Si/Al molar ratio of HZSM-5?Si/Al=27,120?,a series of ZSM-5 catalysts treated with different NaOH concentration?0.1,0.2 and 0.3M?and MCM-41 zeolite were selected as the carriers of catalyst.Ni-Al layered doubleoxidessuppotedonthecarriers?Ni2Al-LDO/ZSM-5-x-n,NixAl-LDO/MCM-41?were prepared by hydrothermal systhesis.Then the catalysts were tested by XRD,N₂ adsorption-desorption and NH₃-TPD to investigate the effect of different catalysts on the yield and component of bi-oil products.The results showed that the bio-oil yield produced by Ni2Al-LDO/MCM-41?26.0%?was much higher than that produced by Ni2Al-LDO/ZSM-5 catalysts?17.9²3.5%?.In comparasion to Ni2Al-LDO/ZSM-5 catalysts,Ni2Al-LDO/MCM-41 was more benefitial to deoxygenation and could produce more nitrogen-containing organics?78.6%?,a high value-added material,of which the content of nitriles was up to78.6%.The catalytic pyrolysis of green algae was operated in self-made fixed-bed reactor by Ni2Al-LDO/MCM-41 catalyst under nitrogen atmosphere.The effect of catalysts and operating parameters were investigated by the study of product distribution and the quality of bio-oil.The results showed that reaction temperature,heating rate and nitrogen flowrate had an important influence.The largest liquid yield?50.5%?and bio-oil yield?19.9%?were prepared under at a nitrogen flowrate of 20mL/min in 450 ^oC with a heating rate of 10 ^oC/min and the catalyst/microalgae mass ratio of 3:4.The content of nitrogen-containing organics was 71.2%,and the nitriles was 53.4%.When the catalytic pyrolysis of microalgae was operated under methanol atmosphere,the largest bio-oil yield?26.0%?was prepared under at a methaol flowrate of 0.06 mL/min in 450 ^oC with a heating rate of 10 ^oC/min and the catalyst/microalgae mass ratio of 3:4.The content of nitrogen-containing organics was 71.2%,and the nitriles was 53.4%.Compared with the same condition under nitrogen atmosphere,the bio-oil product obtained under methanol atmosphere had more N content and the almost same O content.As methanol added to catalytic pyrolysis reaction,the amount of materials in bio-oil reduced from 52 to 23,and the component of bio-oil had a great change.The hydrocarbons and aromatic compounds in the oil were significantly decreased,while the nitrogen compounds increased significantly,especially the content of nitriles increased from 38.1%to 68.5%.