On corrosion behaviour of metal in biomass oil

Biomass oil obtained by the fast pyrolysis of straw is an acidic fuel with pH of 3·4-3·5. It contains a large amount of organic acids, phenol and water and, hence its application in varied industrial fields may result in the corrosion of different metals. In the present study, the corrosion performance of four kinds of iron, lead, steel and copper in biomass oil from the fast pyrolysis of straw was studied at different temperatures and for different test durations using a simulation corrosion evaluation apparatus for internal combustion engine fuel. The corroded metal surfaces were observed by optical micrography and analysed by X-ray photoelectron spectroscopy respectively. The experimental results showed that iron and lead were corroded seriously by the present biomass oil, while the corrosion extents of AISI 1045 steel and copper were significantly less. Layers of oxide and/or hydroxide were formed on these metal surfaces according to surface analysis. However, these layers were not protective of the underlying metals from further oxidation.