Judul: Data inventory of postharvest and extraction of Jatropha curcas Oil
Abstrak: Decreasing stock of petroleum and the global warming it causes has led to the development of production technology of plant oil, such as Jatropha curcas Linn. In Indonesia, it also is supported by national policy of plant oil as biodiesel. J. curcas is suitable for Indonesia since it can grow well in dry and marginal lands. Plant oil production causes concerns that it consumes large amount of conventional fuels, fertilizers, and pesticides, so that it will harm the ecosystem. Life cycle assessment can be used to quantify how beneficial the oil production is in terms of energy use and emission released to environment. The purpose of this research is to develop a data inventory of postharvest and extraction of Jatropha curcas oil, and a program for simulation of the process. In this analysis, some simulations were done in transportation and oil extraction phases. Emissions of process were calculated from its energy consumption. Then, environmental impacts were calculated from the emissions. Results showed the process releasing least emission per litre CJCO was process where fruits were peeled on farms and seeds were grinded before extraction.
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Judul: Study of biodiesel production by in situ transesterification of jatropha seed (jatropha curcas l.) on pilot scale
Abstrak: At present, energy demands have been steadily increasing along with growth of human population and industrialization. Common sources of energy are fossil-based fuels. This growing consumption of energy has rapidly depleted non-renewable sources of energy. The increasing cost and depletion of fossil fuels have motivated researchers to find an alternative source of renewable energy. Moreover, there are many disadvantages of fossil-based fuels, such as atmospheric pollution and environmental issues. Biodiesel (fatty acids methyl esters, FAME) is a promising alternative fuel to replace petroleum-based diesel that is obtained from renewable sources as vegetable oil, animal fat, and waste cooking oil. Vegetable oil are more suitable source for biodiesel production compared to animal fat and waste cooking since they are renewable in nature. Jatropha curcas L. (JCL) is an acceptable choice for biodiesel production because it is non-edible and can be easily grown. Conventional production of biodiesel from Jatropha seeds involve two main processing steps : oil extraction and transesterification to FAME. In this study, feasibility in situ transesterification of Jatropha seeds was investigated on pilot plant. It was found that methanol/hexane/seed ratio effected the yield significantly. With the following reaction conditions: reaction periode 6 hours, 600 rpm stiring speed, 400C reaction temperature, methanol/hexane/seed ratio 3:3:1, and 7 wt% of KOH, the biodiesel yield can reached 89.19%. This single step of in situ alkaline transesterification process therefore can be a potential route for biodiesel production that reduces processing steps and cost.
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Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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