Center for Environmental Research & Technology

Abstract

This research will apply CADO to convert ethanol as an intermediate in the vapor stream released by boiling the fermentation broths in the feed tray for a beer column that separates wet ethanol from solids and other components. Furthermore, the focus is on scaling up CADO technology using the existing NREL pilot plant fed cellulosic biomass per day equivalent to demonstrate low cost production of hydrocarbon fuels. The result will support thus meeting DOE BETO FOA Topic Area 1 Metrics of realizing costs of less than $3.00/GGE and greenhouse gas emission reductions of more than 60% for cumulative stream times over 500 hours and continuous operation for over 100 hours. 

The project plans to start by applying CADO at the bench scale at the University of California Riverside to identify challenges in converting vapor released from wet cellulosic ethanol fermentation broth to hydrocarbons with existing catalyst formulations operated at previously established conditions. First bench scale runs will be made with fuel grade ethanol mixed with water to establish CADO can meet baseline performance of complete ethanol conversion to hydrocarbons, of which 80% will be liquids (C5+). 

The same bench scale CADO system will then be linked with existing bench scale cellulosic fermentation equipment to determine if complete ethanol conversion to at least 80% by weight liquid hydrocarbons is realized over extended run times. If challenges arise in achieving complete ethanol conversion, 80% hydrocarbon yields, and/or extended catalyst lifetime, UCR will modify the catalyst to enhance performance to meet these goals. In addition, UCR will establish operating conditions that maximize performance of the modified catalyst at the bench scale. 

The results will be used to close material and energy balances for the bench operation to support transition to CADO scale up using the existing NREL pilot plant. NREL will first operate with vapor from mixtures of fuel grade ethanol with water to establish baseline CADO performance matches UCR bench scale results with the optimized catalyst. NREL will also integrate their catalytic reactor with their cellulosic biomass fermentation operation and employ the combined system to demonstrate CADO conversion of ethanol in the wet vapor released from cellulosic fermentation broth to hydrocarbons. The project will finally use the data from the NREL pilot scale operation to update the technoeconomic and life cycle analysis models to show CADO application to cellulosic ethanol can achieve DOE BETO FOA goals.