Biodiesel blend (B10) treated with a multifunctional additive (biocide) under simulated stored conditions: a field and lab scale monitoring

摘要

Microbial contamination of stored diesel/biodiesel fuel over time and the consequent changes in the fuel chemical composition is of serious concern. The use of biocides has also been shown to be an effective strategy to address this challenge but in some countries like Brazil, no products have been released and licensed to be used yet. The aim of this study was to evaluate the effectiveness of a multifunctional additive containing a biocide (i.e., 3,3-methylenebis(5-methyloxazolidine); in short MBO) as 50% of its formulation (AM-MBO50) for controlling microbial contamination under simulated storage conditions. The experiment was conducted under two conditions: at lab-scale and in the field (real-world condition). In both experiments, B10 blend treated with AM-MBO50 as well as the untreated fuel blend were stored under simulated storage conditions for 35 and 90 d, respectively. The additive effectiveness and the changes in oxidative stability, water content, density, and viscosity were monitored. The results showed that the evaluated product was an efficient treatment to control microbial growth at 1000 ppm concentration, presenting a biocide action after 7 d in the tanks containing the treated fuel and with a low microbial challenge and a biostatic action in the tanks containing the treated fuel and with a high microbial challenge. In the tanks containing the fuel treated with AM-MBO50, no adhesion of biofilm in the oil/water interface nor meaningful changes in the quality parameters such as oxidative stability, water content, viscosity, and density were observed after 90 d. A comparison between the lab-scale and field results showed that the application conditions determined at the lab-scale can only serve as preliminary guidance for the field (real-world) application and that they should be monitored and adjusted for each specific system.