• The global impact of carbon residue on biodiesel products is significant, as it is related to the emissions that are produced during the combustion process. • The use of low-emission and environmentally friendly fuels is one way to reduce the company's carbon residue. • The productivity of biodiesel and carbon residue in relation to the amount and variation of the catalyst has been studied. • The lowest residual carbon value obtained was 0.010 grams in palm oil feedstock using heterogeneous catalysts. Selecting the right raw materials and catalysts for biodiesel production is important because it affects the residual carbon content produced. The presence of residual homogeneous catalysts, as well as incomplete separation of the biodiesel products, can significantly impact the carbon values. The aim of this study is to investigate the carbon residue of biodiesel products from different catalyst and feedstocks using diesel engines R170A. In this study, the lowest residual carbon value was obtained from palm oil with 5% heterogeneous catalyst with a residual carbon value of 0.010 grams. Gas chromatography and other analytical techniques confirmed the integrity of the carbon atom composition and the emission analysis of the resulting biodiesel. Reproducibility of the heterogeneous catalyst was highly effective in converting coconut oil, with conversion rates of 90.2–89.4% across three experiments. Meanwhile, the recycled catalyst was stable in converting castor oil, with conversion rates of 70.2–69.8% across two experiments.
Affila et al. (Sun,) studied this question.