Details of existing conversion technologies for cellulosic ethanol production, both hydrolysis and
thermochemical, have been discussed along with their present adoption status. Furthermore, economics of
ethanol production by using different conversion technologies has been discussed. Emerging conversion
technologies and other developments which might affect the cellulosic ethanol production are also
characterized. Based on current estimates, it was found that about 400 million gallons of cellulosic ethanol
will be produced in the country in coming years using different conversion technologies. It was noticed that
out of several available conversion technologies, thermochemical-based technologies are gaining popularity
and it is projected that the use of these conversion technologies will reduce the cellulosic ethanol production
cost significantly. Similarly, recent advancements in hydrolysis-based technologies have also helped in
reducing the production cost of cellulosic ethanol. However, more resources will be needed in coming years
to meet the policy goal of producing 21 billion gallons of cellulosic ethanol by the year 2022. It is expected
that this review will be helpful in efficient allocation of resources for facilitating future technology
development and in streamlining the whole initiative of cellulosic ethanol production in the United States.
© 2009 International Energy Initiative. Published by Elsevier Inc. All rights reserved.