Optimization of Jatropha curcas pure vegetable oil production parameters for cooking energy

The extraction of vegetable oil from Jatropha from the Tanzanian variety with a fat content of 33.84 ± 2.58% and a moisture content of 5.4 ± 1.97%, was made using two methods: the traditional and the mechanical extraction method. The traditional consists in extracting the oil from the paste using boiling water as a solvent. While the mechanical consists of directly pressing the seeds of Jatropha using a ram press called Bielenberg press, to extract the oil contained in the seeds dried or heated before. The net yield of oil extraction by the traditional method was 22.02 ± 2.1%, with a oil cake percentage of 67.02 ± 3.3% and the ratio water/paste in mass adopted was 0.36. Mechanical extraction has an average raw yield of 26.15 ± 2.74%, with a recovery rate of 74.71%. After decanting for 10 days and filtration, the net yield was 15.39 ± 2.82% with a decantation and filtration rate of 58.67 ± 7.24%. The oil produced by traditional method has a water and volatile content of 1.01 ± 0.05% and a density of 0.884. The one produced by mechanical extraction has 0.19 ± 0.09% and a density of 0.891. The result of combustion test using two burners and one stove showed that the combustion rates were: 0.177 ± 0.034 g/min for the burner using one flame and 1.06 ± 0.04 g/min for the six flame burner and finally 3.07 ± 0, 4 g/min for the ten-flame stove. This ten-flame stove allowed 3 L of water to be boiled at 100 °C for 32 min, although during combustion it was observed a release of black fumes which indicates incomplete combustion with Jatropha in this Stove. The cost of the liter of Jatropha oil obtained is higher compared to fossil fuels such as petroleum (500 FCFA per liter) and gas oil (624F CFA per liter). It would be possible to use vegetable oil from Jatropha as a cooking fuel.