This project aimed to provide technological proof for the biochemical conversion of low-grade tallow into tallodiesel by enzyme mediated alcoholytic transesterification of fats and free fatty acids to alkyl esters. It also intended to support the potential roll out of this technology via techno-economic study (and initial LCA) to determine an economically beneficial conversion. In the initial stages of the research the aim was to characterise and formulate the stoichiometry of tallow and emulsified fat sources from a selection of tanning industry production facilities. Although the fats are recovered at the early stages of the leather process the production methods contain variations and the raw material sources are not necessarily common, the biggest difference being between the species of animals processed. Total project cost = 186050, DTI grant = 73127