Pemanfaatan Residu Gliserin untuk Menghasilkan Asam Asetat Secara Fermentasi

Abstract

Glycerol residue or frequently known as Pitch is a waste resulted from down stream product of crude glycerin distillation. With the increasing need of pure glycerin in the world, the glycerol residue produced is also in.creasing. Glycerol residue is solid waste at the room temperature, highly alkaline (pH> 13), corrosive, and categorized ac;; waste B3. In this research, the researcher made acetic acid from glycerol residue through the anaerobic fermentation process by using non-sulfur purple photosynthetic bacteria. The purpose of this study was to find out the influence of glycerol residue concentration change on time and to find out whether or not the glycerol residue can be utilized as acetic acid. In the rese~ch, 400 grams of glycerol residue were first diluted with 200 ml of distilled water to change the physical nature of glycerin, from solid to liquid, at room temperature then it was acidified by using hydrochloric acid up to pH2. The top layer formed was fatty acid and triglycerides which should be removed while the bottom layer was the diluted glycerol residue which was then neutralized with caustic soda. To produce acetic acid, glycerol residue with concentration 0.5%, 1.0%, 1.5%, salt and 5 ml non-sulfur purple photosynthetic bacteria were put into a 100 ml bottle which had been previously sterilized, then it was incubated for 4 (four) weeks under the light of 40 watt bulb. The result of this research showed that the acetic acid produced were acetic acid 0.28% a/s (acetic acid weight/sample weight), 1.85% (a/s), and 0.25% (a/s) for glycerin with concentration of 0.5% (a/s), 1.0% (a/s) and 1.5% (a/s) on the 28th day.