GREEN ADDITIVES FOR BIOFUELS: EVALUATING THE MICROBICIDAL POTENCY OF CLOVE, CINNAMON, AND LEMONGRASS OILS IN PROLONGED BIODIESEL STORAGE

Abstract

Fuel microbial degradation and public health safety during prolonged storage, are some of the challenges facing the production and utilization of biodiesel. This research was conducted to evaluate the impact of essential oils (EOs), on biodiesel fuel properties and microbial growth during 180 days storage. Biodiesel samples were blended with single treatments (clove seed oil, cinnamon oil, and lemongrass oil), two-way EOs hybridization, and three-way EOs hybridization. The laboratory analyses were conducted in accordance with the ASTM procedures, CLSI guidelines, and AOAC methods. The GC–MS results revealed that the treatments have significant amounts of phytochemical compounds (eugenol, cinnamaldehyde, neral, and geranial). Using the positive control unit as a baseline, the treatments effectively stabilized the blended biodiesel fuel properties and microbial actions during storage. The hybridized treatments improved the biodiesel induction period, cloud point, and pour point by approximately 103%, 3%, and 14%, respectively. After 180-day storage duration, the negative control (NC), recorded the maximum total bacterial and fungal counts of 756,533 and 690,533 CFU/mL, respectively. The results also established that the Pseudomonas spp. Bacillus spp. Acinetobacter spp. Micrococcus spp, Byssochlamys spp., Aspergillus spp. and Wickerhamomyces spp. populations were highest in the NC sample. Furthermore, the MIC, MBC, and MFC results, confirmed the treatments microbicidal potency, with hybridized treatment S13 and S14 been the most effective treatments, displaying broad-spectrum antimicrobial activity, as well as preserving fuel quality. Interestingly, this research outcome can provides a practical framework, with high value effects both on the automobile industry and microbiology applications, mainly to enhance public safety and sustainability.