Fossil fuel is the main energy resource in Indonesia with oil as the dominant fuel (44.1% of primary energy consumption) in 2017. But fossil fuel is not environmentally friendly and non-renewable. Thus, there is a need for alternative renewable fuels such as biodiesel. Biodiesel from nyamplung (Calophyllum inophyllum L.) oil can provide a promising future as a renewable fuel resource. The used of CaO catalyst from eggshell waste is also profitable, and microwave radiation can help the biodiesel production process run more effectively. Optimization of parameters such as microwave power, catalyst concentration, and transesterification time was performed by using Box-Behnken design. Combinations between biodiesel production from nyamplung oil with CaO catalyst using microwave and treated with Box-Behnken design is considered a new and modern method with optimization of the parameters which affect the transesterification process. The result showed that at a microwave power of 325.24 W, a concentration of catalyst of 3.88%, and a transesterification time of 12.47 min can produce an optimal yield of biodiesel of 98.9079% with the reliability of 92.37%.

Energy demand is currently increasing in line with technological and economic developments, but not accompanied by an increase in energy reserves. So we need another alternative energy that can be renewed, namely biodiesel. Biodiesel has been produced commercially through the transesterification from vegetable oil with methanol using catalyst that produces esters and glycerol. The formation of glycerol which is by-product can reduce its economic value, so it needs to be done the separation process. Therefore, a new route is proposed in this study, namely the interesterification reaction (non-alcoholic route) using methyl acetate as an alkyl group supplier and potassium methoxide catalyst. The superiority of the product produced by the interesterification reaction is biodiesel with triacetin byproducts which have an economical value and can be added to biodiesel formulations because of their solubility so that no side product separation process is needed. To increase the yield of biodiesel and the interesterification rate, the ultrasound method was used in this study. To optimize the factors that affect the interesterification reaction (molar ratio of methyl acetate to oil, catalyst concentration, temperature, and interesterification time), the Box-Behnken design (BBD) is used. Optimal operating conditions to produce the yields of biodiesel of 98.64 % are at molar ratio of methyl acetate to palm oil of 18.74, catalyst concentration of 1.24 %, temperature of 57.84 °C, and interesterification time of 12.69 minutes.

High energy demand in the industrial world and pollution problems caused by the use of fossil fuels causes the need for the latest innovations that will replace the use of non-renewable energy. One of them is the replacement of diesel fuel with biodiesel. At present biodiesel production uses a transesterification reaction which produces a side product in the form of glycerol. However, the presence of glycerol is considered waste and has no economic value so a separation process is needed. So to eliminate the by-product separation process, a new route is used. This route is called interesterification, using methyl acetate instead of methanol which later produces triacetin as a by-product. Triacetin is recognized as an additive in biodiesel which functions as an anti- knocking in diesel engines. In this research, an interesterification study was carried out by ultrasound and a potassium methoxide catalyst was used to increase the reaction rate and the yield of biodiesel. The operating parameters used include the reactant molar ratio of 1:3; 1:6 and 1:9, catalyst concentration 0.5%; 1.0%; and 1.5%, and reaction times 5, 10, and 15 minutes. The parameter optimization is carried out by the central composite design (CCD) method to reduce the number of experiments needed and also to evaluate various variables and their interactions. The optimal operating conditions are the molar ratio of methyl acetate to palm oil of 8.95, catalyst concentration of 1.44%, and interesterification time of 10.03 minutes can produce the yield of biodiesel of 99.66%.

Biodiesel has become a promising renewable energy resource in recent years due mainly to the fluctuating global oil prices. Calophyllum inophyllum L seed has fairly high oil content of about 40-73 % by weight, thus, making it a great potential as raw material for producing biodiesel. This paper aims to study the effect of the microwave irradiation for biodiesel production from Calophyllum inophyllum L oil when solid CaCO3 catalysts made from waste eggshells and synthetic were employed. Furthermore, the effects of operating conditions, including reaction time, microwave power, and amount of catalyst loading were also investigated. The initial step to produce Calophyllum inophyllum L biodiesel was degumming process, followed by the esterification and trans-esterification, respectively. The catalysts used are CaCO3 synthetic and eggshell. The results of production biodiesel from Calophyllum inophyllum L oil give the highest yield of 65.36 % when performed with the microwave power of 300 Watt, 1 % eggshell catalyst and the reaction time of 10 minutes. Therefore, Calophyllum inophyllum L shown as potential biodiesel feedstock.