Patents

An improved continuous process for converting low cost feed stocks containing feed stocks (FFA 20-85%) into alkyl ester with low residence time which comprises: a. Providing feed stocks containing 20-85% FFA without pretreatment or purification; b. Esterifying and transesterifying the feed stocks with lower alcohols (Methanol or Ethanol) in the presence of heterogeneous catalyst (Metal oxide containing mixture of ZnO and Alumina) in single step; c. Process is suitable for homogeneous (NaOH/KOH) as well as heterogeneous catalyst (as mentioned above in b); d. Separating the product as obtained from into upper layer alkyl ester and lower layer glycerol followed by recovering of methanol; e. Washing the biodiesel layer as obtained from step (d) with hot water followed by drying to obtain biodiesel.