Since several generations, oil is being extracted from Pongamia, Hippe and Neem seeds using oil mills and this oil is used for various purposes. One such main use was for lighting lamps. Even today, farmers collect seeds from the Pongamia, Hippe and Neem tress, that grow along the hedges of their fields, extract oil through oil mills and use this oil in various ways.
In recent days, it has been possible to purify these oils to some extent and run tractors, engines of pumps used to draw water and to produce electricity. It is difficult to extract the oil completely from the oil seeds using oil mills. But, approximately 94 percent of oil content can be separated from oil seeds using modern machineries. Depending on the number of the biofuel trees in a region or around a village and based on the amount of seeds obtained in those places, the capacity of the machine required to be established in that region, can be decided.
The oil extracted there should be first given for the use of farmers in that area. This means, the oil directly extracted from the seeds grown by them should be purified and mixed with diesel and this can be used in their tractors, water pump sets and tillers. Additional oil may then be purified and can be converted to biofuel by trans-esterification.
The pulp and seed obtained from the fruits collected from the biofuel trees should be separated and classified. These seeds should be stored so that there is no moisture. If there is moisture, it will give a rancid smell to the seed and spoil the quality of the oil.
More oil content can be extracted if the seed cover is removed using a grinder and crushed before putting it into the machine for oil extraction. Crude oil should be should be thus extracted using the machine from the crushed seeds and it should be purified by removing the impurities. The oilcakes obtained after oil extraction can be used as organic manure.