Assessing the potential of non-edible oils and residual fat to be used as a feedstock source in the enzymatic ethanolysis reaction

Abstract

The focus of this work was to evaluate the potential of non-edible feedstocks to yield biodiesel by an enzymatic route. The ethanolysis of native oils from tropical crops, such as andiroba (Carapa guianensis), babassu (Orbignya sp.), jatropha (Jatropha curcas), macaw palm (Acrocomia aculeata), palm tree (Elaeis guineensis) and industrial waste (beef tallow) in solvent-free system was studied. All reactions were carried out with the microbial lipase from Burkholderia cepacia immobilized on a silica-polyvinyl alcohol matrix in a solvent-free system at 50°C for a maximum period of 24h. Under the conditions tested the biocatalyst was efficient in converting all fatty acids in the lipid feedstocks into the corresponding ethyl esters. Viscosity values for biodiesel samples obtained in each reaction (4.3 and 6.0mm2/s) showed consistent reduction in relation to their original feedstock material, which also confirms the high conversion of triglycerides to ethyl esters (>94.5%). This comparative study shows that the formation of ethyl esters from different non-edible feedstocks was feasible and can provide a considerable increase in the prospect of attaining an environmental sustainability of the process as a whole.