A process for producing dry alcohol includes at least one stage wherein a
gaseous feedstock, which includes alcohol and water, is contacted with
carbon monoxide in the presence of a water-gas shift catalyst, at a
temperature sufficiently high so that carbon monoxide and water are
consumed and carbon dioxide and hydrogen are produced, thereby removing a
portion of the water. The process may include multiple stages; the dry
alcohol produced contains 99.5 wt. % or greater of alcohol and 0.5 wt. %
or less of water. A preferred alcohol is ethanol; dry ethanol can be
combined with gasoline to afford a gasohol.
The water-gas shift reaction is exothermic. The heat generated may be used
to increase the energy efficiency of the process. In one embodiment, the
heat is used to generate high-pressure steam. The high-pressure steam may
be used, for example, to convert feedstock to gaseous feedstock or in the
operation of a production plant.