biodiesel (methyl ester).

2. Triglyceride and fatty acid which are still bonded in triglyceride in the oil is converted to methyl ester via transesterification. By this process, oil conversion to biodiesel (without glyceroyl) of 99.75% can be achieved.

Other feature of this process is the usage of methanol/ethanol reactant can be reduced to < 20% and HCl catalyst can be substituted with solid catalyst from natural substance (FKS) which is much cheaper and can be recycled.

From a production cycle, three grades estrans quality (Fig. 8.3.4) can be obtained : 1) Crude Jatropha Oil (CJO) — as a substitution of kerosene or residue which can be used for direct combustion; 2) Jatropha Oil (JO) — as diesel oil (ADO) substitution for engines with have low rpm (such as portable generator set, tractor/bulldozer, etc.; 3) Biodiesel as fuel (automotive).

Fig. 8.3.5 shows the typical process diagram for jatropha biodiesel production from the seeds. It can be seen, it involves washing, blanching and drying of seeds before proceeding into peeling process. The resulted seed meat is grinded with a grinding machine, the grinded powder is pressed by a hydraulic pressing machine (manual or electric). The crude jatropha oil (CJO) then can be extracted and the residue seed cake can be utilized for animal feedstock, biopesticides, etc.

The production of Jatropha Oil (JO) is carried out by using a estrans reactor where JO is heated at temperature between 50 — 60oC. Methanol as a solvent (5%) is used and HCl catalyst (10% v/v) is applied and then mixed them together. The esterification process will take 2 hours at 50oC. The mixture will direct to a glycerol separator where the aging process will take 4 hours. The glycerol (white paste) will stay at the bottom part whereas the top part JO can be extracted and feed to water separator and neutralization. In this water separator, JO is rinsed twice by using demineralization water, then neutralization is done by using 0.01% of NaHCO3 and finally the deminineralization

using water is carried out again. The final product will be pumped out to the storage tank.

Biodiesel production : JO is fed into an estran reactor with the temperature of 50 — 60oC. The mixture of methanol (10% v/v) and KOH catalyst (0.5% v/v) is then put into the reactor. Stir properly during transesterification process for 0.5 — 1 hour and keep the temperature at about 50oC. Separate the biodiesel from glycerol with the same procedure as JO making. Same procedure also for washing and neutralization process, but in here use 0.01% of CH3COOH instead of NaHCO3. Finally, the final product of Jatropha biodiesel is ready to be used as diesel fuel (ADO) substitution. The characteristic of Jatropha biodiesel is shown Table below.