Comparing the products produced from two global leading biodiesel production from two different feedstocks. Gathered and engineered the production line in Chemcad8 to simulate the process and determine the contaminants. With the results obtained, products specifications are to observed and analyst. Various factors can be affecting the specifications along with the quality of the feedstocks. In the end, Brazil production line from what we engineered is the better one for producing high-quality biodiesel.