Long-Term Corrosion Studies of Pine Derived Bio-Oil and Blends with Heavy Fuel Oil

Biomass derived liquid fuels offer a means to reduce greenhouse gas emissions compared to those produced by combustion of petroleum derived liquid fuels. However, the corrosivity of bio-oils toward the less expensive structural materials creates a material selection problem for designers of storage tanks and combustion systems. Samples of candidate structural materials are being exposed for thousands of hours in multiple fast pyrolysis bio-oils and conditions to evaluate the corrosion resistance of these materials. One method to mitigate the corrosivity of bio-oils and speed their adoption, while also decreasing the pollution issues associated with low quality petroleum derived fuels, is to utilize blends of bio-oil and heavy fuel oil in engines currently solely burning a petroleum-based fuel. In addition to the corrosion studies conducted in 100% bio-oil, studies were also conducted with blends of the fast pyrolysis bio-oil produced from pine tree components with a heavy fuel oil that is used in ocean-going ships. This bio-oil had a very high carboxylic acid content which made it very corrosive to carbon and 2¼ Cr-1 Mo steel and even 409 stainless steel. The heavy fuel oil was not corrosive to carbon steel, but its sulfur content makes it a significant pollution producer and particularly undesirable for use near coastlines. Corrosion tests were conducted with the individual components and with various blends of the two liquid fuels. Studies showed a significantly lower corrosivity of the blends than would be projected assuming linear mixing behavior. Adoption of such blends holds the potential to reduce production of sulfur-containing exhaust gases as well as carbon dioxide from non-renewable fuels.