Andy Aden is a senior chemical engineer at the National Renewable Energy Laboratory in Golden, Colorado. Since 1999, Andy has specialized in process design, simulation, and economic analysis of biomass conversion and biofuels processes. He is well versed on the current and future economics of these processes, which include ethanol and biodiesel but, more importantly, focuses on cellulosic biomass conversion and biorefinery analysis. He completed several pre-feasibility studies for biomass projects in Alaska, California, Oregon, South Dakota, and Wyoming. Since then, Andy has been responsible for techno-economic analysis of many enzymatic biomass conversion research projects and has worked with industrial and university partners on biomass technology integration. He also maintains expertise in life cycle assessment. His most recent contributions have been process design and economic analysis of thermochemical ethanol production via biomass gasification and mixed alcohols synthesis.