Effect of strong base buffer on crude palm oil yield
Abstract Palm oil and its derivatives are widely used in food and oleo chemical industries, and require high yield of crude palm oil (CPO) to fulfill the demand. In palm oil mills, the yield refers to oil extraction rate (OER) that indicates efficiency to squeeze and collect the crude oil from its palm fruit using steam and separation processes. Breakdown of oil cell bearing of mesocarp by the steam may be enhanced by induction of NaOH while the fiber is being digested. The problem of NaOH corrosivity on the steel material of existing unit operations can be controlled by using sodium silicate to form strong base buffer. In this study, the buffer was sprayed on palm mesocarp fiber after 130degC sterilization for 45 min and digestion. The concentration of NaOH in 1 sodium silicate and dosage of the buffer were applied at 0.8, 1.0 and 3.0 mol/L, and 1, 3 and 5 L/tonne, respectively. Pressing extraction was subsequently followed to imitate the current methods in the mills. The extracted liquid was further clarified by using a centrifuge and produced three layers: oil, water and non oily solid (NOS) As an indicator to broken cells, concentration of glucose in a mixture of water and NOS was determined using UV Vis spectroscopy. Oil after centrifuge (OAC) was also recorded. The mesocarp sample treated with the buffer showed improvement of maximum 6.3 wt% of OER and 53.5 wt% of glucose, respectively, implying improvement of oil release using the NaOH buffer.