Ethanol Production
Ethanol is produced either abiotically from direct chemical production, primarily from ethylene, or biotically produced (bioethanol) as a fermentation product. Bioethanol has traditionally been produced via the direct fermentation of crops, such as corn, which contain appreciable amounts of starches and sugars that are fermented into alcohol. This technique continues to be the most popular industrialized fermentation-based production process. Unfortunately, over 70% of the earth’s biomass is not amenable to direct fermentation techniques.
One of the most intriguing ethanol sources is waste products generated from
the processing of both cultured and wild biomass.
Examples include sawdust, wood
chips, cotton ginning waste, bagasse, peanut hulls, sewage sludge, and chicken
litter. Disposal of these waste biomass products is challenging the industries
producing these wastes in terms of locating disposal facilities and cost
(ranging from $15 - $75/ton depending on geographic location and landfill
demand). The production of ethanol from these "waste" sources allows
for the beneficial utilization of these biomass sources as opposed to the
wasting of these carbon sources as a disposal problem. Secondary utilization of
waste biomass involves using these materials as a secondary resource for fuels
production. Secondary utilization eliminates problems with waste disposal, while
fully utilizing the energy value of these biomass materials. Conversely, primary
utilization is the process of producing fuels from biomass that is cultured with
the main intent of producing ethanol. Developing secondary processes for
producing ethanol includes catalytic production from synthesis gas, fermentation
of synthesis gas, and acid hydrolysis extraction of cellulose and hemicellulose
laden wood products. However, none of these processes have been commercialized
to the extent of direct fermentation based on persistent technical and economic
drawbacks.
Mississippi is one of the leading states in agricultural and forestry
activity (gauged in terms of production volume, percent land utilization, and
per capita involvement).
Many of these activities produce a vast quantity of
biomass that is simply managed as a waste disposal problem and not viewed as an
energy resource. The wood products industry in Mississippi is the largest
manufacturing sector in the state employing over 65,000 employees and has a raw
materials stock estimated to be over 3.1 billion dollars. One in every four jobs
in Mississippi is forest product related. These activities include both raw
lumber and wood product manufacturing (Mississippi is the second largest
furniture producing state). Over 4 million tons of wood product waste annually
are not being used for any beneficial product development thus requiring
disposal.