The invention provides methods and apparatus for selectively producing
ethanol from syngas. As disclosed herein, syngas derived from cellulosic
biomass (or other sources) can be catalytically converted into methanol,
which in turn can be catalytically converted into acetic acid or
acetates. Finally, the acetic acid or acetates can be reduced to ethanol
according to several variations. In some embodiments, yields of ethanol
from biomass can exceed 100 gallons per dry ton of biomass.