In this work biodiesel production process is designed and simulated using the process simulator ASPEN Plus®. A detailed kinetic model of the transesterification reactions taking place in the reactor is considered in the simulations. Results show how the residence time in the reactor affects the triglycerides conversion to fatty acid methyl esters, and how it influences the overall process economic potential (EP) and the total potential environmental impact (PEI). Results also show the trade-offs between the studied alternatives, allowing one to conclude that the optimum operating residence time in the reactor is 120min, which corresponds to the lower PEI and the higher EP. Also, for this residence time one can obtain a high TG conversion with low energy consumption.