A perspective on oxygenated species in the refinery integration of pyrolysis oil

Pyrolysis offers a rapid and efficient means to depolymerize lignocellulosic biomass, resulting in gas, liquid, and solid products with varying yields and compositions depending on the process conditions. With respect to manufacture of "drop-in" liquid transportation fuels from biomass, a potential benefit from pyrolysis arises from the production of a liquid or vapor that could possibly be integrated into existing refinery infrastructure, thus offsetting the capital-intensive investment needed for a smaller scale, standalone biofuels production facility. However, pyrolysis typically yields a significant amount of reactive, oxygenated species including organic acids, aldehydes, ketones, and oxygenated aromatics. These oxygenated species present significant challenges that will undoubtedly require pre-processing of a pyrolysis-derived stream before the pyrolysis oil can be integrated into the existing refinery infrastructure. Here we present a perspective of how the overall chemistry of pyrolysis products must be modified to ensure optimal integration in standard petroleum refineries, and we explore the various points of integration in the refinery infrastructure. In addition, we identify several research and development needs that will answer critical questions regarding the technical and economic feasibility of refinery integration of pyrolysis-derived products.