Biodiesel production from oleic acid and nonedible oils using heterogeneous solid acid catalysts

Abstract

Rapid population growth worldwide and the depletion of fossil fuel newlinereserves fronted the research for renewable energy sources which are a newlineprospective alternative to conventional fossil fuels. Biodiesel is an excellent newlinealternative to fossil fuels, can be produced from various renewable sources. newlineBiodiesel is environmentally friendly, biodegradable, shorter CO2 cycle and newlinesustainable. Plant oils such as jatropha, cotton, soybean, canola and palm oil newlinehave been extensively studied in recent years for biodiesel production. newlineVarious techniques such as pyrolysis, catalytic cracking, fermentation, newlinetransesterification have been reported for the conversion of vegetable oils into newlinebiodiesel. All these techniques have both merits and demerits. Among various newlinetechniques, liquid-phase esterification and transesterification using newlineheterogeneous solid catalysts have attracted significant attention to synthesize newlinebiodiesel. The development of heterogeneous solid acid catalysts which are newlineproactive and stable towards simultaneous esterification and newlinetransesterification has received enormous amount of interest. Different types newlineof heterogeneous solid acid catalysts such as heteropoly acids, ion exchange newlineresins, zeolites, sulphated metal oxides, etc., have been reported. newlineHeterogeneous solid catalysts have considerable amount of advantages over newlinehomogenous catalysts (H2SO4, NaOH and KOH) such as reusability, easy newlineseparation and without need of washing. Using an excellent heterogeneous newlinesolid acid catalyst, both esterification and transesterification can be done in a newlinesingle step. Porous cubic Ia3d meso-structured KIT-6 (Korean Institute of newlineTechnology) silica has been proved as an active candidate for biodiesel newlineproduction which could provide in-pore accessibility of acid sites. The KIT-6 newlinebased materials have attracted significant interest in the recent past as a newlinecatalytic support and as a base material due to strong acidity. They have been newlinewidely applied for various types of reactions such as dehydration, newlinehydrogenation and hydroxylation. Apart from these advantages, newline newline