No abstract

Indonesia is known as the largest oil palm producer in the world. However, along with the production, it generates wastes and pollution that caused the environmental problem in surrounding areas. Previous researchers reported that the high palm oil mill effluent (POME) concentration inhibited microalgae growth. However, the inhibition factor was not clearly explained by using kinetic model. This study presents kinetic models of Botryococcus braunii (B. braunii) cultivated on POME wastewater under different turbidity condition. Results showed that the growth model of Zwietering was closely suitable with experimental results. It was found that B. braunii was able to consume organic carbon from the POME wastewater on the logarithmic model. A modified kinetic model of Monod Haldane described the influence of turbidity and chemical oxygen demand on the cultivation. Turbidity of POME medium inhibited the growth rate at KI 3.578 and KII 179.472 NTU, respectively. The Lipid (39.9%), and carbohydrate (41.03%) were found in the biomass that could be utilized as biofuel source.

No abstract

Anhydrous bioethanol is a material used in many applications including biofuel. Commonly, bioethanol is produced through sugar fermentation which results in a low concentration of ethanol. For utilization as biofuel, the lowest ethanol concentration should be 99.5%. Distillation is common technique to dry a mixture solution, however, the mixture of bioethanol and water is forming an azeotrope that limit the concentration of 96% ethanol. This paper discusses ethanol dehydration through extractive batch distillation by the addition of a ternary solute sodium hydroxide, citric acid, sulfuric acid, glycerol or ethylene glycol to ethanol. The initial concentration of ethanol used was 86% v/v, and the amount of ternary solute added was selected based on the colligative properties of the solution, which included a boiling point elevation (ΔT B) that ranged from 5 to 25 °C. All the ternary solutes could break or shift the ethanol-water azeotrope. The highest concentration of ethanol was 99.91% v/v at ΔT B = 25 °C with sulfuric acid as the ternary component. The resulted ethanol concentration exhibited a linear relationship with ΔT B , which was also affected by the boiling point of the ternary solute. This study successfully produced anhydrous bioethanol by low cost and simple distillation process.