Here we report a study on the technical feasibility of using purified animal fat as additive in a diesel fuel for internal combustion engines. The objective is to obtain a base fat with contaminant-free and ready to be diluted in petroleum diesel to obtain a diesel fuel blend with acceptable characteristics in terms of engine-system tolerances. A crude fat refining process composed of a vacuum distillation step and a glycerolysis step to convert the free fatty acids (FFA) recovered from distillation step into triglycerides (TAG) is used. Parametric study to determine the optimal purification-process conditions are used. The TAG obtained after a refining step, is then blended with standard diesel. A satisfactory formulation has already been used to power a system-equipped (converted) diesel engine, and blend ratio of up to 40% in standard diesel perform well enough to run the target engine. The results of this study show that this approach is technically feasible and economically interesting for recovering this waste into fuel. Moreover, it permits a decrease of the fuel carbon balance. (C) 2019 Elsevier Ltd. All rights reserved.