Studi Pengaruh Ukuran Pori Filter terhadap Kualitas Biodiesel Jarak Pagar (Jatropha curcas Linn.) yang Dimurnikan Menggunakan Adsorben.

Abstract

Biodiesel is one of infamous renewable fuel nowadays. Biodiesel is produced from vegetable oils and animal fats. For further usage, biodiesel needs to be purified. The purification method that usually practiced is commonly waterwashing based purification or ‘wet washing’. This method has several weakness and is considered inefficient for removing impurities from biodiesel. The effluent from washing process also cause problems for environmental issues. The actual method which is developed for substituting the waterwashing method is adsorbent-based purification or commonly called ‘dry washing’ method. This method uses adsorbent for removing impurities from biodiesel, which is considered more efficient and less investment than wet ashing method. Filtration becomes one of choices for separating mixture of pure biodiesel and adsorbent. For efficiently separating the mixture, pore size of filter media has to be determined. This research is conducted to determine the best and most efficient filter for filtration purpose, based on the characteristics of both jatropha biodiesel and adsorbent. This research is divided into three steps, which are base material preparation, preliminary research, and main research. At base material preparation, manufacturing of crude jatropha biodiesel and activation of hydrate aluminium silicate and hydrate magnesium silicate as adsorbent are conducted. Preliminary research is conducted to determine the types and comparison between hydrate aluminium silicate and hydrate magnesium silicate as adsorbent. Determination of types and comparison of these adsorbents are conducted using biodiesel characteristics analysis such as acid value, catalys value, soap value, free gyserol value, bound glyserol value, and total glyserol value. Analysis of variance which is used in this step is one-way-ANOVA with one factor, which is the type and composition ratio of the adsorbent (Z). The Z factor is consisted of 11 degrees, i.e. crude biodiesel (without adsorbent), waterwasehd biodiesel (using warm water as purifier replacing adsorbent), and biodiesel which is purified using adsorbent namely hydrate aluminium sylicate 100%, hydrate magnesium silicate 100% and the combination between these two with various ratio: 1:1, 1:2, 1:3, 2:3, 2:1, 3:1, and 3:2. Adsorbent activation process is significant to reduce impurities within biodiesel. According to preliminary research, the best result is obtained when using hydrate aluminium silicate 100%. The characteristics of biodiesel that has been purified using hydrate aluminium silicate 100% are listed such: acid value 0.4373 mg KOH/g biodiesel, undetected catalyst value, soap concentration 53.37 ppm, free-glycerol value 0.0054 %-w, bound-glycerol value 0.2490 %-w, totalglycerol value 0.2490 %-w, dan water and sediment concentration 0.01 %. In main research, the adsorbent used is hydrate aluminium silicate 100% with the concentrate ratio 1.8% from total mass of biodiesel used. The filters which are used have varied pore sizes, range from 2.5, 8, and 20 μm. Filtration that is conducted include one-phase filtration with only one kind of filter used, and multiple-phases of filtration with 2 or 3 layers of filters used. Biodiesel characteristics’ analysis which is conducted include physical analysis, i.e. filtrate yields, transmission-percentage value, and water and sediment concentration. Variety test used for this stage is a one-way ANOVA with one factor, which is type and size of filters with 7 degrees, i.e. single-layer filter vary from 2.5, 8, and 20 μm; double-layers filter vary from 20 and 8 μm, 20 and 2.5 μm, and 8 and 2.5 μm, respectively; and multi-layers filter with 20, 8, and 2.5 μm, respectively. The main research results that the best filter is the filter with 8 μm-sized pores, with filtrate yield 94.185 % w / w; transmission percentage 89.95 %; and water and sediment concentration 0.0125 % - v. In tryout using continuous filter system and 10 μm-sized pores filter media, the results from the filtrate analysis are: acid value 0.05645 mg KOH/g biodiesel; total-glycerol value 0.0484 %-w; free-glycerol value 0.0344 %-w, bound glycerol value 0.0140 %-w, soap concentration 0.00069 ppm; and transmission percentage 76.75 %. The quality of obtained biodiesel has fulfilled SNI standard with lower acid value and total-glycerol value compared to SNI’s values at 0.8 mg KOH/ g biodiesel and 0.24 %-w for each values respectively.