Ionic Liquids To Clean Preparation Of Fatty Acid Methyl Ester

Fatty acid methyl eater is a carbohydrate which could be obtained by transesterification. Esters are generally used in food, plastic derivatives and flavor chemicals and also as precursors for agrochemicals, fine chemicals and pharmaceuticals. Today, the most important and valuable product of fatty acid methyl eater is biodiesel. Biodiesel is biomass energy. The work on biodiesel has gained more and moer attention due to its renewable, biodegradability, better buring property, ability to be blended with fossil diesel under any proportions and can be utilized in conventional diesel engines with no further modifications which could slove the problem of resources shortage. The study on clean preparation of fatty acid methyl eater is of great importance in potential industrial applications and theoretical aspects.In the present work, we synthetized kinds of ionic liquids as catalyst and applied them in transesterification of soybean oil to fatty acid methyl eater. We mainly studied the relativity of the catalystic activity in transesterification and the acid of three ionic liquids. The effect of methanol/oil molar ratio, amount of catalyst and reaction time in transesterification were investigated. The optimum conditions for the transesterification by different catalysts were also obtained which is reference for producing other ester.In the second chapter, we studied the catalytic activity of Brqmsted functional ionic liquid such as1-methyl-3-(propyl-3-sulfoacid)-imidazolium sulfuric acid salt (named as HSO3-pmin]HSO4) and tri-ethy-propyl sulfuric ammonium salt (named as [HSO3-TEA]HSO4). The result showed that the optimum conditions, based on response surface methodology (RSM), were n(soybean oil):n(methanol)=1:13, amount of [HSO;s-pmin]HSO4ionic liquid of4wt%to soybean oil and reaction time8.5h at120℃. Under the optimized conditions, the yield of fatty acid methyl eater reached94.7%. The [HSO3-pmim]HSO4ionic liquid showed highly stability on catalytic activity. Once the [HSO3-TEA]-HSO4as the catalyst, the optimum conditions for the transesterification were as follows://(soybean oil)://(methanol)=1:14, amount of catalyst of4wt%to soybean oil, reaction time8.7h and reaction temperature120℃. Under the optimized conditions, the yield of biodiesel reached94.8%which similar to the activity of [HSO3-pmim]HSO4ionic liquid. The [HSO3-TEA]HSO4ionic liquid could also be reused six times without noticeable drop in activity. The GC-MS analysis of the produce showed that the quality of produce was good and the content of fatty acid methyl eater was98.2%. The main compositions of produce were hexadecanoic acid methyl ester and9,12-octadecadienoic acid methyl ester with34.8%and32.3%respectively.In the third chapter, we studied the catalytic activity of Brcpnsted-Lewis acid ionic liquid such as [HO3S-(CH2)3-mim]Cl-.rFeCl3. The results showed that the activity of ionic liquid correlated strongly with its acidity. And the catalyst showed good catalytic activity when the amount of FeCl3between0.5-0.7. The best yield of fatty acid methyl eater was obtained when the amount of FeCl3was o.6. When the//{soybean oil)://(methanol)=1:16, amount of ionic liquid of6wt%and reaction time24h at120℃, the best yield of fatty acid methyl eater (89.1%) could be obtained. The [HO3S-(CH2)3-mim]Cl-0.6FeCl3ionic liquid could be reused six time without noticeable drop in catalytic activity and no change in structure. The quality of produce obtained by [HO3S-(CH2)3-mim]Cl-0.6FeCl3as catalyst was good.In the fourth chapter, we researched the catalytic activity of supportted catalyst synthesis from sulfonated functionalized cations as the support. The result showed that the loaded Keggin phosphotungstic acid salts (TPAs) catalyst from SO3H-functionalized zwitterions (MIM-PS) as support had good catalytic activity. The catalytic activity enhanced with increase of the proportion of MIM-PS in catalyst. The best yield of fatty acid methyl eater, which was close to the activity of phosphotungstic acid, was obtained when all protons were substituted by MIM-PS. Using [MIM-PSH]3PW12O40as catalyst, the optimum reaction conditions were established as follow:methanol/oil molar ratio of12, amount of catalyst of4%, reactant time of24h at120℃, the yield of fatty acid methyl eater reached72.3%.[MIM-PSH]3PWt2O40could be reused with simple treatment with less wastage and without noticeable drop in catalytic activity and no change in structure. It could be comprehensive application in industry.