Preparation Of Liquid Biofuel From Catalytic Cracking Oil Using Basic Mesoporous Sieve

In recent years,non-renewable oil resources,rising crude oil prices and increasingly serious environmental pollution have become hot topics of common concern at home and abroad,and people have gradually turned their attention to green and pollution-free biofuels.At present,the production of biofuels in China follows the principle of"not competing with the people for food",and low-priced waste cooking oil is mainly used as raw materials.However,the liquid products obtained from the catalytic cracking reaction using waste cooking oil as raw materials have problems such as low yield,high acid value and high coke content.For this reason,several basic mesoporous molecular sieves were designed and synthesized in this paper as catalysts for cracking waste cooking oil,which effectively improved the yield of liquid biofuel,reduced the acid value and greatly reduced the coke content.The specific research contents are as follows:Basic mesoporous molecular sieves Me O/Ca-MNC-13（Me O=K₂O,Mg O,Ba O）were prepared by impregnation method using triethylamine ionic liquid[HSO₃-（CH₂）₃-NEt₃][Cl]as template agent andβzeolite doped with basic metal element as guide agent.Its structure and alkalinity were characterized by XRD,N₂adsorption/desorption,CO₂-TPD,and the results showed that the synthesized samples had excellent mesoporous structure;K₂O/Ca-MNC-13 had the largest alkali content and total alkali content,with the strongest alkalinity and the best catalytic activity.When used to catalyze the cracking reaction of waste cooking oil,the yield of liquid products is as high as 63.5%,the yield of coke is reduced to 11.9%,and the content of hydrocarbon compounds in liquid products is about 60%.Using K₂O/Ca-MNC-13 as catalyst,the optimum process conditions for cracking oil were investigated as follows:cracking temperature and time were 430℃and 90 min,m（Catalyst）:m（WCO）=1:30.The reusability of K₂O/Ca-MNC-13 was investigated under the optimal process conditions,and it was found that it still maintained excellent catalytic activity after being used for 5 times;and it has excellent universality for catalytic cracking reaction of linseed oil and castor oil.The basic mesoporous molecular sieve X-BMC-22（X=K,Ca,Mg）was prepared by one-pot method using imidazole ionic liquids[Bmim]Cl as templates andβzeolite was introduced into the synthesis process.The structure and basicity of the samples were characterized by XRD,N₂adsorption/desorption,FT-IR and CO₂-TPD.The results showed that they all have excellent mesoporous structure and relatively large pore size,which is more conducive to the catalytic cracking of macromolecular oils;K-BMC-22 has more basic sites,the largest total alkali content,the highest catalytic activity,and the highest yield of liquid products obtained by catalytic cracking of waste cooking oil,the content of hydrocarbon compounds is up to 70%,and the content of acidic compounds is low to 9.4%,the acid value decreased significantly,which significantly improved the oil performance.Using K-BMC-22 as the catalyst,the optimum process conditions for cracking oil were investigated as follows:cracking temperature and time were 430℃and 90 min,m（Catalyst）:m（WCO）=1:30.The reusability of K-BMC-22 was investigated under the optimal process conditions,and it was found that it still maintained excellent catalytic activity after being used for 5 times;and it has excellent universality for catalytic cracking reaction of linseed oil and castor oil.Using imidazole ionic liquids[Bmim]Cl as template agents andβzeolite was introduced into the synthesis process,basic metal oxide-modified Me O/Mg-BMC-32（Me O=K₂O,Ca O,Ba O）were prepared by impregnation method.The structure and basicity of the samples were characterized by XRD,N₂adsorption/desorption,CO₂-TPD,and the results showed that they all had regular mesoporous structure.Ba O/Mg-BMC-32 has a large pore size,which is conducive to the catalytic cracking of macromolecular oils and has the highest catalytic activity,and the yield of catalyzed waste cooking oil to obtain liquid products is as high as 70.5%,the yield of residues is only 11.4%,the content of hydrocarbon compounds in liquid products is as high as 80%,the content of acidic compounds is as low as 6.13%,and the acid value is obvious decreased,the oil performance has been significantly improved.Using Ba O/Mg-BMC-32 as catalyst,the optimum process conditions for cracking oil were investigated as follows:cracking temperature and time were 430℃and 90 min,m（Catalyst）:m（WCO）=1:30.The reusability of Ba O/Mg-BMC-32 was investigated under the optimal process conditions,and it was found that it still maintained excellent catalytic activity after being used for 5 times;and it has excellent universality for catalytic cracking reaction of linseed oil and castor oil.