When the biodiesel feedstock contains more than 2-3% of free fatty acids (FFAs), acid esterification is a useful upstream step to avoid the formation of high soap.
Lapho i-biodiesel feedstock iqukethe ngaphezu kwama-2-3% wamafutha amahhala ama-acids (ama-FFAs), ukuqinisekiswa kwe-asidi kuyisinyathelo esiwusizo esiphezulu sokugwema ukwakheka kwensipho ephezulu.