Many NGOs which work for upliftment of Tribals have found this model very effective. There are two schemes.
Scheme 1 : The NGOs set up Hand Operated Expellers like these, (which do not require electrical power) in their centers. Tribals come to these centers with their bags containing any Oil Bearing Seed like Jatropha, Neem (Non Edible oils for lamps), Pongamia, Mahua (Edible oils for Cooking) and crush the seeds themselves. The tribals carry the extracted oil home for burning these in oil lamps and for cooking. The Tribals leave the seed cake in these center. The NGOs then process the seed cake to Bio Fertilizer in their centers, and sell it later. Tribals collect sufficient seeds, during harvesting period to last for a year, but crush these to get oil as and when required.
Scheme 2 : The same NGOs buy the oil, extracted as above and sell it to Temples, Hotels, Households for burning them in simple lamps, as a social cause. The NGOs also tie-up with soap manufacturers for buying oil from them, at a specified rate. The profit from sale of oil is passed on to Tribals as reasonably good price.
There is a two step process to convert seed cake into BioFertilizer. In first step the seed cake is fermented in BioGas Plant shown below.

The cake coming out of BioGas plant is then further processed in a simple, low cost, BioFertilizer plant as shown below.

In these sheds the seed cake is eaten by earthworms (shown below) and bacteria to produce BioFertilizer. Water is sprinkled on the cake heap, which is kept moist at all times. It is turned upside down once a day. It takes 3 to 4 months to complete the process. It provides employment to a number of tribals.

I am associated with a Non Government Organization (NGO), PRAGATI PRATISHTHAN in Thane district of Maharashtra, just 100 miles from Mumbai, which works for Jatropha Plantation in number of villages, where we plan to plant 10 million (1 Crore) Jatropha saplings, in the monsoon season, in the ADIVASI (Aboriginal) lands. The saplings will be shortly ready and farmers along with owners of non productive / barren land are ready for Jatropha plantation. With these plantations, we will reduce CO₂ from atmosphere, and lend a small hand in reducing Climate Change Disasters. We are ready to do the plantation in 10,000 Acre of land during this monsoon season starting June 2009.

An Electricity Generating set is now commissioned in the same village. The engine runs on 100% Jatropha Oil (Not Diesel or BioDiesel blend). It lights up Two Electric Bulbs each, in 50 houses of the village. It is a new experience for the villager's in their life time.

Extraction of Jatropha oil from Seeds

Oil is filtered before use

Oil is used as fuel for Diesel Engine

Production of Bio Gas from Jatropha Seed Cake

Production of Bio Fertilizer from Treated Jatropha Cake

Net House to produce Saplings from Seeds