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As energy needs continue to rise in line with the use of fossil energy, which is difficult to renew, other alternative energy is needed to continue to meet current and future energy needs. One alternative energy that is easy to produce is biodiesel. One of the raw materials that is quite widely used and developed in making biodiesel is waste cooking oil. According to statistical data, Indonesia can produce waste cooking oil of 5.06 tons per year. Waste cooking oil contains free fatty acids that can be processed into biodiesel using the help of heterogeneous catalysts. One source of heterogeneous catalysts that can be used is CaO, which can be found in green shells, where the CaO contained can be taken through the calcination process of green shells. To maximize the waste cooking oil processing process, an adsorption pretreatment process can be carried out. The adsorption process is carried out to reduce the FFA levels and acid numbers contained in waste cooking oil so that the transesterification reaction process can run optimally. Natural zeolite can be used as a good adsorbent to purify and lower the acid number of waste cooking oil. This study aims to find the best operating conditions in producing biodiesel made from waste cooking oil with a pretreatment adsorption process using natural zeolite and green shell catalyst through the factorial design method, where from the results of the research carried out, it was found that the density and viscosity met the SNI, the biodiesel yield produced was 45-65% and the cetane number test on samples 3 and 7 was 34,7 and 34,2 which did not meet the SNI. The operating temperature and amount of catalyst used in the biodiesel manufacturing process produce biodiesel with good density, viscosity, and yield, namely at a temperature of 60°C and a catalyst content of 6 grams. The operating temperature of 65°C produces a smaller density because the boiling point of alcohol is 64.7°C, so the reaction process is not perfect. [ABSTRACT FROM AUTHOR]

Highlights: [•] Lipid composition Xylocarpus moluccensis seed oil. [•] Biodiesel production from X. moluccensis seed oil. [•] The fatty acid quantification of biodiesel obtained from X. moluccensis seed oil. [•] The physico-chemical properties of biodiesel produced from X. moluccensis seed oil. [ABSTRACT FROM AUTHOR]

Abstract: The transesterification of palm oil to methyl esters (biodiesel) was studied using KOH/zeolite as solid heterogeneous catalysts. Various process variables such as KOH concentration and reaction time were studied in order to obtain maximum yield of biodiesel. A series of KOH/zeolite catalyst was prepared by impregnation of zeolite from Pacitan with potassium hydroxide in a various concentration (25g KOH in 100mL of distilled water; 50g KOH in 100mL of distilled water; 75g in 100mL of distilled water; and 100g in 100mL of distilled water). The weight ratios between zeolite and KOH solution were 1:4. Transesterification was carried out at various reaction times (1 to 4h). The impregnation of zeolite with KOH concentration of 100g/100mL gave maximum yield of biodiesel. The natural zeolite, catalyst, and spent catalysts were characterised by using several techniques such as XRD, EDX, and SEM. [Copyright &y& Elsevier]

The objectives of this study are to identify the energy balance of Indonesian palm oil biodiesel production, including the stages of land use change, transport and milling and biodiesel processing, and to estimate the amount of greenhouse gas emissions from different production systems, including large and small holder plantations either dependent or independent, located in Kalimantan and in Sumatra. Results show that the accompanied implications of palm oil biodiesel produced in Kalimantan and Sumatra are different: energy input in Sumatra is higher than in Kalimantan, except for transport processes; the input/output ratios are positive in both regions and all production systems. The findings demonstrate that there are considerable differences between the farming systems and the locations in net energy yields (43.6 to 49.2 GJ t-1 biodiesel yr-1) as well as greenhouse gas emissions (1969.6 to 5626.4 kg CO2eq t-1 biodiesel yr-1). The output to input ratios are positive in all cases. The largest greenhouse gas emissions result from land use change effects, followed by the transesterification, fertilizer production, agricultural production processes, milling and transportation. Ecosystem carbon payback times range from 11 to 42 years. [ABSTRACT FROM AUTHOR]