Materials compatibility issues with biomass-derived oils

Production of liquid fuels and higher value chemicals from biomass provides a means to lessen our dependence on fossil fuels and, consequently, contributes to a reduction in production of greenhouse gases. However, thermochemically derived products from biomass contain large quantities of oxygen-containing compounds, and there are undesirable characteristics associated with these biomass-derived oils. The carboxylic acids, particularly formic acid, are corrosive to many common structural alloys, and other compounds, particularly ketones, cause degradation of many of the common elastomeric materials used for seals in liquid systems. New analysis techniques, including separations and structurally descriptive mass spectrometry, have been developed to characterize these bio-oils, laboratory corrosion studies have been conducted to assess the effects of the bio-oils on both metallic and nonmetallic materials, and examinations have been conducted on metallic samples and components exposed in operating liquefaction facilities. Results indicate preferential internal oxidation occurs in some 300 series stainless steels and degradation of many elastomeric materials is found after exposure in a mixture containing partially hydrotreated bio-oil.