INFLUENCE OF AXENIC CULTURE OF BACILLUS CLAUSII AND MIXED CULTURE ON BIOFILM FORMATION, CARBON STEEL CORROSION, AND HYDROCARBON DEGRADATION IN B30 STORAGE TANK SYSTEM

• Main Author: Aslan, Christian
• Format: Theses
• Language: Indonesia
• Subjects: Teknik kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/62028
• Institution: Institut Teknologi Bandung

INFLUENCE OF AXENIC CULTURE OF BACILLUS CLAUSII AND MIXED CULTURE ON BIOFILM FORMATION, CARBON STEEL CORROSION, AND HYDROCARBON DEGRADATION IN B30 STORAGE TANK SYSTEM Biodiesel is a renewable biofuel product that is more environmentally friendly. Biodiesel is used in Indonesia as a diesel blend with a composition of 30%-v biodiesel and 70%-v petrodiesel (B30), under the Biodiesel Mandatory Program. However, biodiesel has some disadvantages, namely more hygroscopic, easily degraded, and more polar in structure. This causes the occurrence of biocorrosion or Microbiologically Influenced Corrosion (MIC). MIC can occur in diesel blend storage tank systems. This research aims to determine the influence of microorganisms on the formation of biofilms, carbon steel corrosion, and hydrocarbon degradation in B30 storage systems. Axenic culture isolate of Bacillus clausii and mixed culture isolate from biofilm formed in carbon steel immersed in B30 will be used in this research. Results showed that the corrosion rate of carbon steel in the biotic condition is higher than in abiotic condition, with mixed culture is higher than the axenic culture of B. clausii. Furthermore, the increase of total acid number in the biotic condition is higher than in abiotic condition, with mixed culture is higher than the axenic culture of B. clausii. The MIC process by mixed culture is more complex, which involves anodic and cathodic reaction, corrosion attack by H2S, direct consumption of electrons, hydrogenase enzyme production, the interaction of IOB and IRB, corrosion attack by ferrous ion, organic acids production, and EPS production. Meanwhile, the MIC process by the axenic culture of B. clausii involves only anodic and cathodic reaction, organic acids production, and EPS production. Results also showed that carbon steel has outstanding relative corrosion resistance because the uniform corrosion rate of carbon steel exposed at the oil phase in the B30 diesel blend storage tank is very low. However, the dangers of pitting corrosion attacks and corrosion that occurred at the oil-water interface also need to be considered.