Biomass derived liquids offer a potential for conversion into liquid fuels such as gasoline, jet fuel, diesel, and fuel oil. However, the bio-oils, whether produced by any of a number of processes, contain significant concentrations of water and oxygen-containing organic compounds. Of the oxygenates, carboxylic acids constitute a significant fraction, and these compounds, primarily formic and acetic acids, make bio-oil quite acidic. Unless the carboxylic acids are removed, bio-oil presents corrosion issues for materials used to construct the systems used for production, processing, transport and storage of the bio-oil.
Techniques have been developed to improve characterization of the bio-oils, and laboratory corrosion studies have been conducted with both the organic and aqueous fractions to assess the corrosivity of the biomass-derived materials. In addition, samples have been exposed in operating systems, and components of these systems, as well as the exposed samples, have been examined to assess the extent of degradation. The results of these characterization studies will be described and recommendations for materials sufficiently resistant to these environments will be provided.