One-pot conversion of sesame cake to low N-content biodiesel via nano-catalytic supercritical methanol

Abstract

The fatty acid methyl esters (FAMEs) and H2 were produced from sesame cake in supercritical mixture of methanol and water using alumina supported CaO and MgO nanoparticles. The fresh and used catalysts were characterized by ICP-OES, BET, XRD, and TEM techniques. The significant influence of catalysts on the gas production was revealed. Further, the highest amounts of H2, CO, and CO2 was achieved by MgO/γ-Al2O3 with the hydrogen fraction more than 7.6 times, compared with the non-catalytic process. For biodiesel, CaO/γ-Al2O3 showed the best performance where 35.3% of the liquid product was FAMEs, more than 2.3 times relative to the non-catalytic process. In order to reduce the amounts of nitrogenate content in the liquid fuel, an efficient and scalable method implemented with the Soxhlet apparatus and the absorption tube equipped with CO2 gas flow system. Accordingly, the N-contents of the liquid products were reduced to highest degree of 65.2%, asserting that the reduced amount of the N-content strongly depends on the catalyst during the production process.