Pembuatan Biopelet Dari Bungkil Jarak Pagar (Jathropa Curcas L.) Dengan Penambahan Sludge Dan Perekat Tapioka

Abstract

Seed of jatropha (Jatropha curcas L) contains 60 % kernel (weight) and 40 % husk (weight). Its nucleus’s seeds contain 40 – 45 % oils that can be separated into jatropha oil either with mechanical or extraction way (Hambali et al. 2006). More than its 60 % component is an oil cake. The huge amount of oil cake can be used as a solid fuel such as Biomass Pellets (Biopelet). Biopelet has diameters 3 – 12 mm and 6 – 25 mm long. Biopelet is produced by continuous inlet dry materials that is pushed and pressed through steel ring that has particular holes. The pressing process produces solid materials that will be broken into specific size (Ramsay (ed) 1982). Jatropha oil cakes have a weakness as a solid fuel. It has no high heating value and its physic characteristic that has low binder. The addition of sludge in this research are expected to increase the heating value. Sludge can be used as an alternative heating resource. Binding problems can be solved by adding tapioca. Tapioca is used because the price is cheap. But it has a weakness, tapioca will decrease heating value on the product. Binding agents also produce smoke. Optimum adding of tapioca is not more than 5% (Sudrajat and Soleh, 1994). The most important parameter of Biomass fuel is heating value (Grover et al, (eds) 2002). Heating values implies energy that is binded on the fuel with standard from environment. The standard are temperature, water (liquid or vapor), CO2, O2, etc (Palz, 1985). This research starts with physic and burning characterizations of jatropha oil cakes. Biopelet produce in the pellets mill that has capacity 350 kg/ hour. Production held in PT Indofeed Bogor. Biopelet parameters test conducted at Laboratories of Biomass Energy and Chemistry, Forest Product Research and Development Center. The final step of this research is found the comparison of quality between biopelet jatropha oil cake with adding sludge and tapioca and biopelet jatropha oil cake without adding sludge and tapioca. Experimental design used in this research is using Random Complete Design with two factors (RAL factorial). The first is the addition of sludge treatment with three levels, which is, 2%, 4% and 6%, while the second factor is the addition of tapioca adhesive that also has three levels of treatment, which is 1%, 3% and 5%. From the results of the research obtained, although the results of interaction from two factors of treatment, the sludge and tapioca adhesive does not produce real difference, but with the combination can further improve value of the some expected parameters. Combination of sludge 6% and 3% tapioca, can increase heating value to 4914 Kcal / kg, meaning that the combination treatment can increase the heating value 5.62% of the value content from biopelet (control ). So also for bound carbon, a combination of sludge 6% and 1% tapioca can increase the level of bound carbon of 24.41% of the value content of carbon bound control, the combination treatment has value of carbon content of 20.59%. v The addition of sludge and tapioca adhesive provides a less good measure of the parameters of the water content, fly substance content, and ash content, although the impact is relatively small. The addition of sludge in 6% and 1% tapioca adhesive increasing water content up to 1.68% of the value of water level control. Sludge addition of 6% and 3% tapioca lower fly substance content to 3.01% of control values. And the influence of the addition of sludge and tapioca adhesive also provides the increased value of ash content, a combination of sludge 2% and 5% tapioca adhesive is who has the lowest value of ash content. Overall, although the interaction influence not significantly, it can be concluded that with the combination of certain sludge and tapioca adhesive can produce biopelet that has a better quality. Financial feasibility analysis show that biopelet jatropha seed oilcake is feasible based on the criteria established test, the NPV value is positive (223.881.458) and IRR (16,13%) is greater than the discount rate (15%). Sensitivity test againts increasing and decreasing of raw materials price and selling prices indicate that biopelet industry is sensitive, particularly to price changes.