Treatment of industrial low grade palm oil via esterification reaction using sonoreactor

•This study introduces low grade palm oil (LGPO) to produce biodiesel.•Treated LGPO can be considered as a new raw fuel material produced via sonoreactor.•The biodiesel produced meets the International Biodiesel Standards.•Sonoreactor proves to be a useful device for biodiesel production from LGPO. In this study, the reduction of free fatty acid (FFA) in low grade palm oil (LGPO) was conducted at various sonication times, ranging from 30 to 300min. Screening of various acids was reported and selected acid was considered for further study. The results found that strong acids such as sulfuric acid to be superior to other acids. The FFA content of LGPO decreased from 20% to less than 3%, using sulfuric acid at optimum conditions. Treated LGPO can be used as a new type of fuel for various applications such as biodiesel production.