MIHAELA GABRIELA DUMITRU, DRAGOS TUTUNEA EXTRACTION AND DETERMINATION OF PHYSICO-CHEMICAL PROPERTIES OF OIL FROM WATERMELON SEEDS (CITRULLUS LANATUS L) TO USE IN INTERNAL COMBUSTION ENGINES The purpose of this work was to investigate the physicochemical properties of watermelon seeds and oil and to find out if this oil is suitable and compatible with diesel engines. The results showed that the watermelon seeds had the maximum length (9.08 mm), width (5.71mm), thickness (2.0 mm), arithmetic mean diameter (5.59 mm), geometrical mean diameter (4.69 mm), sphericity (51.6%), surface area (69.07), volume 0.17 cm3 and moisture content 5.4%. The oil was liquid at room temperature, with a density and refractive index of 0.945 and 1.4731 respectively acidity value (1.9 mgNaOH/g), free fatty acid (0.95 mgNaOH), iodine value (120 mgI2/100g), saponification value (180 mgKOH/g), antiradical activity (46%), peroxide value (7.5 mEqO2/Kg), induction period (6.2 h), fatty acid: palmitic acid (13.1%), stearic acid (9.5 %), oleic acid (15.2 %) and linoleic acid (61.3%). Straight non food vegetable oils can offer a solution to fossil fuels by a cleaner burning with minimal adaptation of the engine. A single cylinder air cooled diesel engine Ruggerini RY 50 was used to measure emissions of various blends of watermelon oil (WO) and diesel fuel (WO10D90, WO20D80, WO30D70 and WO75D25). The physic-chemical properties of the oil influence the combustion process and emissions leading to the reduction of NOX and the increase in CO, CO2 and HC.
Keywords: Emissions, watermelon seeds oil, non food oil