MILD-CARBON STEELS AS A STORAGE TANK MATERIAL FOR BIODIESEL PRODUCT: A CORROSION ASSESSMENT

Abstract

In the practice of biodiesel storage tanks, there are questions about their long-term viability for handling and storage. This study examined the effects of biodiesel blends containing B0, B30, B40, and B100 products on the corrosion resistance of carbon steels graded AISI 1020 and AISI 1045. Static corrosion tests for 168 hours at 25°C were performed by immersing test coupons of each carbon steel in the biodiesel blending solution. An electrochemical analysis revealed that the AISI 1020 and AISI 1045 coupons had current density (Icorr) values higher than 0.1 µA/cm2 . In various biodiesel blends, the corrosion rates for AISI 1020 and AISI 1045 increased from 0.02275 to 0.051184 mmpy and from 0.04777 to 0.05890 mmpy, respectively. The results show that mild steels used to store biodiesel have a limited ability to resist corrosion. The oxygen content of biodiesel may affect the corrosion products of mineral rusts (Fe2O3, Fe3O4) on steel surfaces. Because of its significantly higher oxygen content, steel-AISI 1045 has a faster corrosion rate than steel-AISI 1020. The study findings could provide a technical explanation for the corrosive nature of biodiesel storage tanks.