Pilot Scale Production of Mixed Alcohols from Wood

Abstract

An integrated thermochemical biomass to ethanol process was demonstrated at the pilot scale at the National Renewable Energy Laboratory (NREL). A total of 233 h of pilot scale mixed alcohol production was achieved, comprising 81 h of continuous operation in methanol-derived syngas followed by 152 h of continuous operation in biomass-derived syngas. During this period the system generated 20 L of mixed alcohol product. 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-liquid reactor (CSTR). Additional pumps, compressors, and blowers were used to convey gases, solids, and liquids. Tars and methane were reformed using sequential steps: first in a fluidized bed using an NREL-developed Ni-based catalyst followed by a fixed bed reactor loaded with pelle...