Nrel's Integrated Biorefinery Research Facility - Pilot Scale Solids Handling Risk Mitigation

NREL's Integrated Biorefinery Research Facility – Pilot Scale Solids Handling Risk Mitigation

Jane C. Fisher, P.E., Daniel J. Schell, Richard T. Elander, David A. Sievers, Joseph Shekiro, and Timothy Johnston, National Renewable Energy Laboratory

To achieve commercial-scale production of cellulosic ethanol at a cost that is competitive with gasoline, it is crucial to understand the entire integrated biorefining process and how one stage of the process can impact the performance of the others.  With the addition of the Integrated Biorefinery Research Facility (IBRF) at the National Renewable Energy Laboratory (NREL), the cellulosic biofuels industry has access to a significantly expanded pilot plant and biochemical conversion process research facility.  At NREL, the goal is to improve the cost effectiveness of cellulosic biofuels production processes and thereby to accelerate commercial scale deployment of these technologies.  A number of aggressive government policies are guiding NREL's approach to cellulosic ethanol and other cellulosic biofuels research and development (R&D), including the 2007 Energy and Independence and Security Act requiring 36 billion gallons of renewable fuels by 2022, and President Obama's New Energy for America Plan calling for 60 billion gallons of advanced biofuels by 2030.  The IBRF's new integrated and flexible process R&D piloting capabilities will enable a wide variety of biofuels technology developers to reduce risks associated with scaling up to demonstration and full-commercial scales.  Many of the risks to be mitigated are related to solids handling, which presents a variety of challenging technical issues that the cellulosic biofuels industry must resolve to successfully transition the conversion technologies from pilot to demonstration scale and ultimately to commercial scale.  The IBRF was completed in two stages and includes provisions to evaluate a wide variety of sustainable biomass feedstocks (corn stover, switch grass, sorghum, etc).  During completion of the first stage startup and commissioning a number of solids handing issues were encountered and to some extent resolved. Second stage design modifications were implemented to address the solids handling issues experienced during the first stage. The design changes were primarily associated with storage hoppers and discharge screws, pneumatic conveyance, cyclone separation, weigh belt feed, and dust collection. Design considerations for biomass feedstock handling as well as lessons learned during first and second stage facility commissioning and startup will be discussed.