Feedstocks for ethanol production

Feedstock Any material converted to another form of fuel or energy product. For example, com starch can be used as a feedstock for ethanol production. 

One of the most common feedstocks for ethanol production is corn, which has been widely used in the USA. The starch in corn is converted to glucose after grinding in a dry mill, reacting it with dilute acid and then reacting it with amylases, e.g. a-amylase and glucoamylase. The free glucose is then available for fermentation to ethanol. 

Alfalfa (Medicago sativaL.) is a feedstock for the production of fuel, feed and other industrial materials. Alfalfa consists mainly of celluloses, hemicelluloses, lignin, pectin and proteins. Therefore, it is a potential feedstock for ethanol production and also other chemicals. 

The potential of Jerusalem artichoke as a feedstock for ethanol production has been assessed in many countries in recent years. In New Zealand, for instance, Jerusalem artichoke gave the highest potential ethanol yield (calculated from known crop yields and fermentable content) of a range of crops assessed. From three harvests of the tops a year, estimated ethanol production was 78 It-1 and 11,230 1-ha-1. Although fodder beet (Beta vulgaris L.) remains a favored feedstock for ethanol production in New Zealand, Jerusalem artichoke has been recommended for further study (Judd, 2003). 

Baker, L., Thomassin, P.J., and Henning, J.C., The economic competitiveness of Jerusalem artichoke (Helian-thus tubemsus) as an agricultural feedstock for ethanol production for transportation fuels, Can. J. Agric. Econ., 38, 981-990, 1990. 

Another potential feedstock for ethanol production is the lignocellulosic biomass . Lignocellulosic biomass is the most plentiful of all naturally occurring organic compounds. It includes such materials as wood, herbaceous crops, agricultural and forestry residues, waste paper and paper products, pulp and paper mill waste, and municipal sohd waste. Unlike starchy materials, lignocellulosic biomass is structurally complex. The conversion of this material into ethanol has been the subject of intense study over the last 20 years. 

Production of orange and grapefruit juice generates large amounts of residues. These residues, mainly peel and segment membranes rich in carbohydrate, are potential feedstock for ethanol production. Upon hydrolysis, the residue gene-... 

The current ethanol supply is, in the large part, derived from starch. Nevertheless, vast amounts of agricultural residues and other lignocellulosic biomass can serve as the feedstock for ethanol production. Theoretically, enough ethanol can be produced from cellulosic biomass to meet most of the liquid fuel requirements in the US. The expanded utilization of lignocellulosic biomass for ethanol production can also free starchy crops for food and other uses. In addition, less carbon dioxide emission can be realized if more ethanol can be produced from lignocellulosic biomass and if the market for ethanol as a transportation fuel can be expanded beyond the current level. 

Wang D, Bean S, McLaren J, Seib P, Madl R.Tuinstra M, et al. Grain sorghum is a viable feedstock for ethanol production.JInd Microbiol Biotechnol 2008 35 313-20. 

Li, C., Champagne, R, 2005a. Enzymatic hydrolysis of cellulose from various waste sources and their feasibility as feedstocks for ethanol production. In Proceedings of the 20th International Conference on Solid Waste Technology and Management. 

In the following section more detailed information will be given of the conversion of methane (biogas) into ethylene as feedstock for ethanol production via oxidative... 

---