Assessment and Control of Biomass Growth in Fuel Storage Tanks at the KNPC Phase II: Evaluation of the Effectiveness of Biocides in Controlling the Microorganisms Causing Problems in Oil Products Tanks

K. Mataqi*, S. Jose, B. Mathew, Salman Al-Saffar


Microbiologically induced corrosion (MIC) can lead to several deteriorating outcomes in the oil industry. The growth of microorganisms(bacteria) in fuel storage tanks results in costly maintenance measures as well as alteration in oil product specifications, which lead to issuessuch as corrosion of steel and fiberglass reinforced plastic tanks, tank linings, elastomeric seals and hoses, low points in the piping, leakdetectors, turbine pump components,filters,valves, etc.The objectives of the project were to screen different biocides on controlling MIC in storage tanks, to identify the optimum dosage ofbiocide needed to control microbial growth in each petroleum product, and to analyze the fuel quality after treatment with biocides.Minimum inhibitory concentrations of seven biocides were estimated and three biocides were selected for detailed study (Acticide CMG,Kathon FP 1.5 Biocide, and Predator 6000). Predator 8000 was found to be similar to Acticide CMG, Kathon FP 1.5 Biocide in chemicalcomposition, and MBC, so it was not included in the coupon weight loss study. Predator 8000 was found to be similar to Acticide CMG,Kathon FP 1.5 Biocide in chemical composition, and MBC, so it was not included in the coupon weight loss study. These biocides are equallyeffective in the prevention of microbial growth; did not change weight of mild steel coupons (custom made circular coupons of an average2.45 cm diameter and 0.35 cm thickness, which were made from the same material as of the fuel storage tank were used to check whetherthe biocide have a corrosive effect); and did not affect the quality of fuels. But under the electron microscopy study, it was proved thatPredator 6000 treated coupons had lesser degree of corrosion when compared to that of Acticide CMG and Kathon FP 1.5 Biocide treatedcoupons. So Predator 6000 was selected as the best biocide.