Biodiesel Production From Leftover Olive Cake

Leftover olive cake is a kind of biomass fuel being used with high calorific value for heating in industry and at homes. Even in the best technologies oil may remain in proportion of %8-10 in its cake as a result of processing olive. Oil obtained by the method of extraction from leftover olive cake is called crude pomace oil. Crude pomace oil after refining processes may also be used as olive pomace oil. Crude pomace oil is a biomass fuel with high calorific value available as fuel in compression-ignition (CI) engines. However due to high free fatty acid (FFA), in direct use of engines causes problems because of negative effects such as blockage of the fuel pump and injectors, bad odour during combustion, the amount of sediment left on the cylinders and injectors, high viscosity and density value. For this reason properties of crude pomace oil must be improved. In this study the way of improving by the method of transesterification is preferred for crude pomace oil to be used in engines. Methanol (CH3OH) in the rate of purity %99.7, Potassium Hydroxide (KOH) and Sodium Hydroxide (NaOH) in the rate of purity %98.5, sulphuric acid (H2SO4) in the rate of % 95.5 are used for transesterification reaction. It is determined that FFA amount specified according to three different methods is high for transesterification conversion. For this reason biodiesel production of crude pomace oil was carried out in three stages. In the first stage the improvement of the amount of FFA of the oil is aimed. Therefore in the 1st stage CH3OH in the mole fraction of 20:1 (alcohol/oil) and with H2SO4 of %10 in volume is subjected to reaction for an hour at 55-60oC temperature. As to in the second stage CH3OH in the mole fraction of 40:1 (alcohol/oil) and with H2SO4 of %5 in volume after being subjected to reaction for an hour at 55-60 oC temperature the reaction was repeated in company with KOH and NaOH for the production of biodiesel. It is observed that the properties of the obtained fuel are in accordance with the standards of EN 14214 and ASTM D-6751. © Sila Science