Effect of Palm Oil Sterilisation Technology on Aqueous Co-Products Characteristics

With the recent development and new technologies adopted at palm oil mills, the characteristic of aqueous co-products should be updated besides exploring their potential applications. This study was conducted to characterise the aqueous co-products generated from steriliser condensate and sludge separator involving four types of sterilisers (horizontal, continuous, vertical and tilting sterilisers) and empty fruit bunch (EFB) press. The biochemical oxygen demand (BOD) and chemical oxygen demand (COD) concentrations of the overall aqueous co-product were 23 400-36 000 mg L^-1 and 53 000-80 000 mg L^-1, respectively. The concentration of suspended solids (SS) and oil and grease (O&G) were 21 000-45 000 mg L^-1 and 2800-10 200 mg L^-1, respectively. Total nitrogen (TN) concentration was 940-1600 mg L^-1, while the ammonium nitrogen (AN) concentration was 37-174 mg L^-1, with pH ranging from 4.5-5.8. This study indicated that all processing types yield aqueous co-products which were within the range compared to previous studies. The powder generated from the aqueous co-product contained 10.0% oil, 11.7% protein, 5.1% moisture and 13.1% ash. Other minerals such as phosphorous (P), magnesium (Mg), calcium (Ca), zinc (Zn), manganese (Mn) and potassium (K) were also present in the aqueous co-products. (author)