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.