Partnerships, Future, and Emerging Technologies - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 402

Fig. 19.1 GHG benefits of cellulosic ethanol compared to first-generation ethanol
potential ghg benefits of various cellulosic ethanol technologies, current first-
generation corn ethanol, and an advanced future state of the corn ethanol industry
as they compare to gasoline based on values given by Hsu et al. [ 8 ]. These ghg
values incorporate using the lignin component to supply the heat and power needs
of the conversion process in the cellulosic ethanol cases and an increased biomass
component in the advanced corn ethanol state [ 9 ]. Another benefit of cellulosic
ethanol over first-generation ethanol is that cellulosic ethanol has a much-improved
net energy balance [ 10 ], and similar to the ghg emission benefits, much of this
benefit comes from utilizing the lignin component to supply the heat and power
needs for the conversion process.
Conversion Technologies
Although there are a multitude of variations, there are essentially two main tech-
nology approaches for producing cellulosic ethanol from lignocellulosic biomass.
The first route, commonly referred to as the biochemical route, utilizes a sugar
intermediate, which is fermented into ethanol, and the second route utilizes a
syngas intermediate, which can either be fermented or catalytically converted to
ethanol. Both routes have received considerable amount of public and private