(277e) Demonstration of Biomass Conversion to Mixed Alcohols At the Pilot Scale

An integrated thermochemical biomass to ethanol process was demonstrated at the pilot scale.  This process entailed both fuels synthesis catalyst activation and operation on biomass derived syngas.  The sum of these activities comprised more than 500 hours of pilot scale operation. The fully integrated biomass to mixed alcohol process was comprised of a solids feeder, fluidized bed indirect steam gasifier, thermal cracker, char collector, fluidized bed steam reformer, packed bed polishing steam reformer, scrubber, pressure-swing CO₂ adsorber, and gas-phase continuously stirred tank gas-to-liquids reactor (CSTR). Tars and methane were reformed using NREL-developed steam methane reforming catalysts and mixed alcohols (including ethanol) were produced using a metal sulfide catalyst. The goals of this study were to identify operating conditions and syngas compositions that are obtainable with NREL’s gasifiers and gas cleanup equipment, to prove an ability to operate continuously for long periods, and to identify major impacts that biomass syngas may have on the fuel synthesis catalyst as compared to bottled syngas, as well as demonstrate scaled liquids production.

During this talk, the performance of the entire integrated process and each process unit will be discussed, and the key lessons learned will be addressed. The implications of this pilot-scale demonstration on future research as well as on commercialization of mixed alcohol production processes will also be discussed.