PNNL

Abstract

Biomass derived oils are renewable fuel sources and commodity products and are proposed to partially or entirely replace fossil fuels in sectors generally considered difficult to decarbonize such as aviation and maritime propulsion. Bio-oils contain a range of organic compounds with varying functional groups which can lead to polarity-driven phase separation and corrosion of containment materials during processing and storage. Polar compounds, such as organic acids and other oxygenates, are abundant in bio-oils and are considered corrosive to structural alloys, particularly to those with low Cr content. To study the corrosion effects of small carboxylic acids present in pyrolysis bio-oils, type 410 stainless-steel (SS410) specimens were exposed in bio-oils with varying formic, acetic, propionic and hexanoic acids at 50°C during 48-hour exposures. Specific mass change data showed a linear increase in mass loss with increasing formic acid concentration. Interestingly, mild corrosion inhibition effect on corrosion of SS410 specimens was observed with addition of acetic, propionic and hexanoic acids in the bio-oil.