The Effect of Alkali Concentration and Hydrolysis Time on the Production of Oxalic Acid from Wood Sawdust Waste by Alkali Hydrolysis Process

Abstract

Mahogany wood is a type of wood often found in sawmills because the wood grows faster than other types of wood, so a lot of mahogany sawdust is wasted and not utilized in a product that is discarded and has economic value. The wood residue from removal is then used as a raw material for oxalic acid (C₂H₂O₄₎ products through an alkali hydrolysis process. This study aims to determine the effect of sodium hydroxide (NaOH) and reaction time on the quantity and quality of C₂H₂O₄ formed in the NaOH extraction reaction on mahogany sawdust. In this process, the mahogany sawdust was reacted with NaOH concentrations of 1 N and 3 N with variations of coarse and fine mahogany sawdust and reaction times of 60 min and 120 min. To obtain C₂H₂O₄, this research was carried out with several stages of pre-treatment, hydrolysis with NaOH, precipitation with calcium chloride (CaCl₂), acidification with sulfuric acid (H₂SO₄), and crystallization. The quality of the C₂H₂O₄ obtained was analyzed by High-performance Liquid Chromatography (HPLC). The best conditions for producing C₂H₂O₄ from mahogany sawdust were NaOH at a concentration of 1 N with a reaction time of 60 min and a yield of 15.67 % from coarse mahogany sawdust.