Experimental Study On Catalytic Cracking Of Jatropha Oil By Molten Base

With the increasing energy and environmental crisis,animal and vegetable oils and fats,as a renewable biomass resource,have received extensive attention using their processing to convert into hydrocarbon fuel oils.Catalytic cracking of oils and fats is considered to be one of the most effective methods for preparing hydrocarbon fuel oils.There are many catalysts for catalytic cracking of oils and fats.In this paper,the effects of catalyzed cracking on Jatropha oil were investigated in a high pressure reactor using NaOH and KOH molten alkali with heat carrier and catalysis.The specific research conclusions are as follows:?1?Experimental study on catalytic cracking of Jatropha oil with NaOH molten alkali.The effects of reaction temperature,feed rate and stirring speed on catalytic cracking reaction were investigated.The optimum experimental conditions are 390?,1.6 mL·min^-11 and 500 r·min^-1,the liquid product yield is 60.57%,the acid value is 0.45mgKOH·g^-1,the density is 0.8442 g·cm^-3,the content of alkane is 55.49%,the content of olefin is 29.48%,and the content of aromatic hydrocarbon is 4.27%,the content of oxygenate is 8.43%,the content of short chain compound of C₉ and below is 33.06%,the content of C₁₀^C₁₄4 component is 34.50%,the content of C₁₅^C₁₉9 component is29.15%,the content of the polymer compound of C₂₀0 and above is 0.96%;The study of adding different catalysts was carried out under better experimental conditions.From the results,it was found that the selection of pure NaOH molten alkali was more favorable for obtaining higher liquid yield and alkane content than adding catalyst.?2?Experimental study on catalytic cracking of Jatropha oil with KOH molten alkali.The effects of reaction temperature,feed rate and stirring speed on the catalytic cracking reaction were investigated.The optimum experimental conditions are 390?,1.4 mL·min^-11 and 500r·min^-1,the liquid product yield is 56.75%,the acid value is 0.23mgKOH·g^-1,the density is 0.8659 g·cm^-3,the content of alkane is 27.22%,the content of olefin is 26.33%,and the content of aromatic hydrocarbon is 8.35%,the content of oxygenate is 33.52%,the content of short chain compound of C₉ and below is 3.34%,the content of C₁₀^C₁₄4 component is 47.58%,the content of C₁₅^C₁₉9 component is44.16%,the content of the polymer compound of C₂₀0 and above is 0.34%;The results of adding different catalysts under better experimental conditions show that the addition of CaO and Fe₂O₃ catalysts can increase the liquid yield and reduce the acid value of liquid products,increase the content of alkanes and olefins,and reduce the content of aromatic hydrocarbons and oxygenates.The addition of MgO catalyst can increase the content of C₉ and below short-chain compounds and C₁₀^C₁₄4 components,and reduce the content of C₁₅^C₁₉9 long-chain compounds;The experiment of catalytic cracking of Jatropha oil with different proportions of NaOH-KOH composite molten base under suitable conditions shows that the NaOH molten alkali is more favorable for obtaining higher quality liquid products than KOH molten alkali.?3?Kinetic study on catalytic cracking of Jatropha oil with NaOH molten base,the activation energy of the reaction is 4.5228kJ·mol^-1,the frequency factor is 0.1498min^-1,and the kinetic equation is=0.1498·e^{0.544 T};The composition of the liquid product obtained by catalytic cracking of jatropha oil by molten alkali shows that the liquid product is mainly composed of alkanes,cycloalkanes,olefins,diolefins,aromatic hydrocarbons and oxygen compounds,and the carbon chain is mainly distributed in C₅^C₂₀,which is contained in the liquid product.A small amount of a substance having a carbon number of 20 or more is considered to be a polymerization reaction of a short-chain compound under high temperature;According to the analysis of the reaction mechanism,the molten alkali not only serves as a heat carrier to provide heat for the reaction,but also participates in the reaction.Under the action of the molten alkali,more ketones and esters are converted into alkanes or olefins by decarboxylation or decarbonylation,releasing carbon monoxide or carbon dioxide.The content of this study has a certain guiding role in the preparation of hydrocarbon fuel oil by molten base catalytic cracking oil.