THE INFLUENCE OF WATER CONTENT ON BIOFILM FORMATION AND METAL BIOCORROSION PROCESS IN BIODIESEL STORAGE TANKS

• Main Author: NUR RAMADHANI NIM: 23016005, AIDA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25218
• Institution: Institut Teknologi Bandung

<p align="justify"> <br /> <br /> Biodiesel is a potential biofuel to be applied as an alternative fuel. Biodiesel is usually stored in a storage tank of carbon steel which has weaknesses easily corroded by microorganisms. Corrosion occurs because microorganisms use fuel as a source of nutrients. The water content in hygroscopic biodiesel supports microorganisms to grow and metabolize. Microorganisms that contribute to corrosion events include Bacillus megaterium. <br /> <br /> <br /> This research was conducted to determine the effect of water content on biofilm formation and biocorrosion by Bacillus megaterium, and its effect on the quality of fuel. The experiments were carried out by immersing carbon steel specimens in immersion medium for 21 days with variation of biodiesel concentration in medium (B0, B20, B30, and B100) and water addition on medium B30 (0%, 5%, and 10%). <br /> <br /> <br /> From the experimental variation, the highest average corrosion rate was 0,642 ± 0,28 mm / yr achieved by B30. The number of colonies in biofilms increased up to 1,3 times in a 10% water addition when compared with no water addition. A uniform biofilm provides an inhibitory effect on corrosion per time, as well as a layer of iron phosphate formed on water addition variation. Differences in biodiesel concentration have no effect on the biofilm composition, such as alcohol, fatty acid, protein, polysaccharide, and carboxylic groups. While on the variation of water addition, the polysaccharide group undergoes a shift, indicating that the biofilm formed are less strong and easily removed. The corrosion products of Bacillus megaterium are Fe2O3, Fe3O4, and FeOOH. Decreased quality of fuel occurs in all variations, B0 has the greatest %Biodegradation Efficiency at 81,97%, and the highest increase in acid numbers occurring at B100, which increases up to 1,4 times. <br /> <p align="justify"> <br />