Bifunctional Ethoxy-Amine Modified Silica Catalysts for Green Energy: Facilitating High Biodiesel Yield via Enhanced Methanol and Oil Adsorption

Abstract This study works on the synthesis and characterization of an APTES [(3-aminopropyl) tri ethoxy silane] impregnated silica catalyst for the transesterification of vegetable oil into biodiesel. It was aimed at increasing the silica catalytic activity by using different concentrations of APTES as a modifier which would mount the basic amine groups to the silica surface. Synthesis and functionalization of the silica was confirmed through the use of various characterization methods such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared), XRD (X-ray diffraction), and BET (Brunauer-Emmett-Teller). Of the four synthesized catalysts, the highest yield of biodiesel which was 62.2 percent was obtained from the catalyst containing 0.75g of APTES used at 65 degrees Celsius for 5 hours with 0.3g catalyst and reaction time. GC (Gas chromatography) showed a promising FAME (fatty acid methyl esters) profile which suggests the FAME would have good properties essential to low temperatures as well as for aiding in the biodiesel cold flow properties. Over 90% of the catalytic activity was retained after three uses. The catalyst maintains more than 90 percent of activity after three uses demonstrating stability and reusability.The silicate catalyst yielded superior results compared to conventional catalysts since it performed better with regard to environmentally friendly approaches, flexibility, and efficiency for large scale production of biodiesel.