Biofuels and Biorefineries
Andrew's work on Biofuels focused on generating viable and high-value replacements to fossil fuels. By their nature, biofuel feedstocks are highly variable, and Andrew’s goal was to characterize key aspects common to most feedstocks and analyze their individual and combined effects with pyrolysis catalysts. While Andrew's work has ended at Cornell, research in this area continues through this and other labs. The ultimate goal is to create a system to adapt to changing feedstock options, and utilize the best processes available to convert these feedstocks into a stable and energy-dense alternative fuel.
Abridged Dissertation Executive Summary
Anthropogenic climate change is driving the need for renewable and carbon free/neutral technologies to offset and replace traditional fossil fuels. One category of viable fossil fuel alternatives is biobased fuels – hydrocarbons in liquid, solid or gaseous form derived from dedicated crops, agricultural or municipal waste, or animal byproducts. These hydrocarbon fuels benefit from the high energy density of their chemical bonds, potentially reaching levels close to fossil fuels. Additionally, biobased fuels can be used in the existing combustion-focused infrastructure in transportation and power generation. Biobased fuels are carbon neutral (when properly managed) and can be used to sequester atmospheric carbon by generating solid biochars composed of stable graphitic carbon.
While there are numerous routes to generate biobased fuels, this work focuses on thermochemical conversion (specifically pyrolysis) of lignocellulosic biomass. Pyrolysis utilizes high temperatures under atmospheric pressure and anoxic conditions to devolatilize biomass and generate bio-oils, gases, and carbonized chars. The lack of oxygen prevents the biomass from combusting. Lignocellulosic biomass represents an underutilized resource. The United States generates hundreds of millions of tons of crop residues per year, which are typically left to decompose and return carbon (largely in the form of carbon dioxide) back to the atmosphere. The majority of this carbon is recycled between plants and atmosphere, and by converting these crop residues into biofuels, that carbon can be stored and used before returning to the carbon cycle.
