Extraction of Acetic Acid from Bio-oil using Aqueous Salt System

Acetic acid surged as high-value chemical due to its wide application in industrial chemical. Acetic acid can be extracted from bio-oil derived from various biomass such as agriculture waste. In this study, the extraction of acetic acid from bio-oil is investigated based on the composition of acetic acid in empty fruit bunch. Liquid – liquid extraction method namely aqueous salt solution is proposed as this method is simple and can be conducted at room temperature. Synthetic bio-oil with composition of acetic acid (10 %), aldehyde (20 %), acetone (10 %), phenol (30 %), and water (30 %) was prepared and characterized. It is found out that the effective phase separation of bio-oil can successfully been conducted through addition of aqueous salt solution. In this study, aqueous ammonium sulphate, (NH4)2 SO4, is used to perform phase separation and the effect of salt concentration on recovery of acetic acid from bio-oil is investigated. Research conducted has revealed that the upper layer mainly contains acetic acid and water-soluble compounds meanwhile the bottom layer consists of water-insoluble, non-polar compound. The acetic acid composition at the upper and lower phase relies on the type and dosage of the salt added. Based on the result, it is found out that the highest amount of acetic acid extracted in upper phase is achieved using 15 % of (NH4)2 SO4 in bio-oil with yield of 25.27 %.