Land Clearing Life cycle inventory in the production of biodiesel from palm oil

52 Oil palm plant starts flowering and forming fruit after 2-3 years. The fruit ripening process can be observed from the change of its skin color. The fruit will turn red orange when ripe. The oil content reaches maximum amount at the time the fruit reaches its optimum ripeness. If too ripe, the fruit will be detached and fall from the bunch stalk. The process of palm oil harvesting consists of cutting the ripen bunch, picking the fruits and transport the harvested bunch to the collection point and to the mill. Harvesting criteria which should be consideredis the harvesting criterion, harvesting tool, rotation, harvesting system and crop quality. - Harvesting criterion: harvesting criterion is an appropriate indication that can help harvesters to cut the fruit at the optimum ripeness. Ripening index is when the fruit reach maximum oil content and minimum free fatty acids FFA. At this time, the general criteria that are widely used are based on the number fruit group, i.e.a plants with age less than 10 years haveless than 10 fruits per fruits group, and b plants with age more than 10 years old have 15-20 fruits per fruits group. However, in practice, people commonly use criteria with two fruits groups per 1 kg FFB. One key factor to maintain the yieldvalue is to keep the value of FFA of CPO or CJCO under 5. Under this condition, the biodiesel process can be carried out using transesterification reaction. If the FFA value is higher than 5, esterification process should be conducted first before transesterification. The shorter the process will turn to higher yield. - Harvesting method: Based on the plant height, there are three common methods to harvest palm oil in Indonesia. Squat with dodos is used to harvest palm oil with 2-5 m height, standing using axe tool is used to harvest palm oil with 5-10 m height, and sickle with long handle egrek is used to harvest palm oil with more than 10 m height. For ease of harvesting, the stem should be cut first and orderly arranged in the middle of gawangan. - Harvesting preparation: To deal with harvesting season and in order to make the process run smoothly, collection results TPH should be prepared and the transportation road should be improved.

7. Milling Stage

Crude palm oil as known as CPO is produced from the extraction of fruit mesocarp. As oil or fat, palm oil is a triglyceride, which is a compound of glycerol with fatty acids. In accordance with the form of the fatty acid chain, palm oil includes an oleic-linoleat acid oil. Harvested fresh fruit bunches FFB should be immediately processed. The process to obtain palm oil involves sterilization, threshing, cutting, and pressing. Pressing process will produce a liquid phase oil and solid phase in the form of waste. Liquid phase still contains a lot of impurities such as sand and fibers that need filtration and clarification to separate these impurities. FFB processing flow chart to produce CPO at palm oil milling plant in PTPN Kebun Unit Kertajaya VIII is shown in Appendix 5, and the mass and energy balance is shown in Appendix 6.

8. Biodiesel Production Stage

Simple biodiesel production process is shown in Figure 3.10. Biodiesel is made by reacting CPO with methanol through transesterification reaction and