Corrosion behavior of carbon steel, stainless steel, aluminum and copper upon exposure to biodiesel blended with petrodiesel

In this study, the compatibility and corrosion behavior of carbon steel, stainless steel, aluminum and copper in contact with blends composed of biodiesel (consisting of soybean oil, beef tallow and swine lard) and petrodiesel were evaluated. Static immersion tests (total, partial and crevice) and exposure in vapor phase were carried out for 2160 h at 50 degrees C. Our main findings indicate that fuel blends influence the corrosion behavior, being observed a less corrosive attack on the materials, except for copper that presented an anomalous corrosion behavior, with a clear trend towards lower corrosion rates. Carbon steel and stainless steel in total, partial and crevice tests presented surface morphology with slightly changes, while carbon steel exposed in vapor phase showed corrosive attack. Copper presented the highest corrosion rates in partial (9.5273 mu m/y), total (9.1484 mu m/y) and crevice (6.6178 mu m/y) tests in the B7 blend, respectively; and the lowest corrosion rates in total (0.0547 mu m/y) for the B15 blend; in partial (0.4926 mu m/y) and crevice (0.0182 mu m/y) tests for the B30 blend. Among the materials evaluated, copper showed higher influence on biodiesel oxidative stability. Aluminum exhibited good compatibility and did not show any compound formed on its surface without presenting any corrosion. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study explores the compatibility and corrosion behavior of different metals in contact with biodiesel-petrodiesel blends. Copper exhibited anomalous corrosion behavior, while aluminum showed good compatibility without corrosion. The fuel blends influenced the corrosion behavior of materials, with copper having a significant impact on biodiesel oxidative stability.