Production of Coco-Biodiesel from CNO (Coconut Natural Oil) for Small Scale Industries/Coconut Farmers Using Static Mixer and Dry Washing

Abstract

Coco-biodiesel is a derivative product of coconut (copra) and is a substitute for diesel fuel. The production of coco-biodiesel is a solution when the price of fossil fuels is uncertain and increasing. In addition, producing coco-biodiesel for coconut farmers will increase the added value of coconut, ensure the availability of local fuel, and support integrated coconut processing. The objective of the study is to introduce a process and equipment prototype for processing coco-biodiesel that can be operated on a small scale which is suitable for coconut farmers, especially in remote areas. Coconut natural oil (CNO) was mixed with 0.1% phosphoric acid in a tank, heated for 2 hours at 80°C, and settled for 4 hours. After that, the transesterification reaction was carried out by reacting coconut oil with methanol with a molar ratio variation of 1: 10, 1: 6, and 1: 4. The process was conducted at a temperature of 65°C and a flow speed of 1.25 m/s (on a static mixer) and using methanol 98 % and 1% KOH catalyst. The crude coco-biodiesel washing was done using dry washing (membrane filter), the results of which were compared with washing using hot water. The type of membrane filter used was ultra-filtration membrane with a membrane area of 0.0055 m2, length of 1200 mm, and porous size of 0.2-1.2 micrometers. The optimum condition of triglycerides synthesis into fatty acid methyl esters (coco-biodiesel) to produce a 96.5% content (requirement) was obtained at a molar ratio of 1: 6. Acid numbers, total glycerol, free glycerol, density, viscosity, and Iodine number of coco-biodiesel produced were <0.5, 0.1%, 0.02%, 855 kg/m3, 3.6 cSt, respectively. The values of these parameters meet the Indonesian biodiesel standards. The performance of dry washing exhibited the capacity of biodiesel washing of 0.56 kg/minute or 0.65 l/min, an energy consumption of 315 kJ/kg which was less than the energy consumption of water washing (1361 kJ/kg).