Design and testing of a solar photovoltaic operated multi-seeds oil press

Oil expression tests were conducted to evaluate the performance of a novel oil expeller designed and fabricated to operate on a 200 W solar photovoltaic (PV) power system as a sole power source. The oil press was designed to press oilseeds meal with intermediate moisture content of 12 +/- 1% (w.b.) and 0.5-2mm particle sizes. Freshly grated coconuts and ground peanuts were used to determine the oil expression efficiency of the press. The oilseed samples were pressed for 12 min with a maximum pressure of 3.0 MPa being reached at 6 min of pressing for peanuts and 8 min of pressing for coconuts. The pressure was then held for the rest of the pressing time. The press attained an average oil expression efficiency of 73% for coconuts and 70% for peanuts. The force-vs.deformation studies indicated that peanut press meal was compacted at a higher rate as compared to coconuts. The observation on the energy consumption indicated that there was a significant increase (P < 0.05) in the specific energy requirement for both coconuts and peanuts after 6 min of pressing, which resulted from the solidification of the press cake. An average specific energy of 36.55 and 20.35 Wh/kg was recorded for peanuts and coconuts, respectively, after 12 min of pressing. 2005 Elsevier Ltd. All rights reserved.