THE INFLUENCE OF BIODIESEL CONCENTRATION IN DIESEL OIL FOR CORROSION OF CARBON STEEL BY Bacillus licheniformis

• Main Author: Febrianto, Dani
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/38495
• Institution: Institut Teknologi Bandung

Indonesian government encouraging utilization of alternative energy source biodiesel up to 30% v/v at 2020 with policy from minister of energy and mineral resource number 12 year 2015. However, the hygroscopic nature of biodiesel makes it more susceptible to contamination of microorganisms, especially the corrosion-influencing one. At the process of distribution, diesel-biodiesel mix fuel contained at carbon-steel tank. This material used because of its strong and inexpensive advantages. But, one of the major flaws of carbon steel is it easily corroded either chemically or by microorganisms. Evaluation of microorganism activity at diesel-biodiesel mix medium have been researched at ITB. However, both researchers used microorganism based on literature study, B. megaterium and S. marcescens. This research conducted to study the activity of microorganism which isolated from corrosion product that involves hydrocarbon such as diesel oil, Bacillus licheniformis, The medium used for the experiment is diesel oil (Pertamina Dex) with variation of biodiesel concentration in the medium (B15, B20, B30). As standard of comparison, soaking at Pertamina Dex and FAME were also conducted. The conducted analysis were cell amount counting with TPC, biofilm component maker with FTIR, corrosion products with XRD, and corrosion rate with gravimetry. From the conducted analysis, concluded that Bacillus licheniformis growth at biofilm is influenced by biodiesel concentration in the diesel oil medium. But, greatest colony number found at FAME/B100 medium, followed by Pertamina Dex medium. That fact caused by bacteria needs more adaptation time at B15, B20, and B30 medium. The increasing of biodiesel concentration isnt proportional to corrosion rate. Highest corrosion rate found at Pertamina Dex medium (0,1503 ± 0,049 mm/year) with B. licheniformis activity. The variation of biodiesel concentration has no effect to biofilm composition and corrosion product. Biofilm consisted of product of biodiesel degradation, such as acetate acid and fatty acid, and EPS building compound such as carbohydrate and protein. Corrosion products that produced by activity of Bacillus licheniformis are Fe2O3, FeOOH, and Fe3O4