Influence of adsorbent-arak ratio and distillation period in bioethanol purification process using Balinese liquor as a raw material

Abstract: Arak is one of traditional Balinese drink that has potential alcohol content used as a raw material in making bioethanol. The aim of this research was to study the influence of adsorbent-arak ratio and distillation period on the characteristics of bioethanol and to identify the right method to produce bioethanol with the best characteristics using distillation-adsorptive purification method. This research used a completely randomized design with factorial experiment. The first factor was an adsorbent-arak ratio, i.e., 1:2, 1:3 and 1:4. The second factor was the distillation period, i.e., 1, 2, 3 h. Each factor was grouped into two groups based on the two times of arak production so that there were 18 experimental units. The data was analysed using Analysis of Variance (ANOVA) and means were compared by Duncan’s multiple range test. The result showed that the ratio of adsorbent-arak and distillation period had a significant effect on ethanol content, density, specific gravity, API gravity, and heating value. The combination of 1:3 adsorbent-arak ratio and one-hour distillation period produced the best characteristic viz.,: ethanol content 91.86 %, density 0.83 kg/L, specific gravity 0.81, API gravity 42.31, and heating value 11081.9 kcal/ kg.