Ethanol production from

Eig. 15. Eurfural, phenols, and ethanol production from wood in a multiproduct process biomass chemical plant (52). Wood (qv) is ca 50% cellulose (qv),... 

Table 31. Net Energy Production Ratios for Ethanol Production from Com in Integrated System ...

Table 8.7. Ethanol productivity from immobilised systems...

The most studied system for agricultural waste recycling is their bioconversion into fiiels [1], such as ethanol production from sugarcane molasses, citrus peels [2] and whey [3],... 

Kemppainen, A.J. Shonnard, D.R. (2005) Comparative Life-Cycle Assessments for Biomass-to-Ethanol Production from Different Regional Feedstocks. Biotechnology Progress, 21(4), 1075-1084. 

Such intensive use of land will make very large demands on available water supplies and soil corrosion is also an important issue. There is even a debate over the overall reduction in fossil energy use and actual contribution to C02 abatement for the case of ethanol production from com [9]. Since waste arises from biomass or fossil fuel, to introduce waste products in the conversion scheme, which of course should be done, does not help in the overall scheme we discuss here. This is bom out by economic predictions (Table 1.2). 

The inner cavity of carbon nanotubes stimulated some research on utilization of the so-called confinement effect [33]. It was observed that catalyst particles selectively deposited inside or outside of the CNT host (Fig. 15.7) in some cases provide different catalytic properties. Explanations range from an electronic origin due to the partial sp3 character of basal plane carbon atoms, which results in a higher n-electron density on the outer than on the inner CNT surface (Fig. 15.4(b)) [34], to an increased pressure of the reactants in nanosized pores [35]. Exemplarily for inside CNT deposited catalyst particles, Bao et al. observed a superior performance of Rh/Mn/Li/Fe nanoparticles in the ethanol production from syngas [36], whereas the opposite trend was found for an Ru catalyst in ammonia decomposition [37]. Considering the substantial volume shrinkage and expansion, respectively, in these two reactions, such results may indeed indicate an increased pressure as the key factor for catalytic performance. However, the activity of a Ru catalyst deposited on the outside wall of CNTs is also more active in the synthesis of ammonia, which in this case is explained by electronic properties [34]. 

The advances made in enzymatic hydrolysis of cellulosic materials (14) are also of interest. This technology involves only moderate temperature processes in simple equipment which promises to be of significantly lower capital cost than the pressure equipment associated with conventional acid wood hydrolysis processes. All of these considerations combined to lead us to study processes for ethanol production from wood, especially in an effort to obtain data for material and energy balances, and possibly for the economics. 

A summary of the factors which are known to influence ethanol production from glucose in a gas-solid fluidized bed fermenter, or which may have an influence based on observations with submerged fermentations, is shown in Figure 6.1. In anaerobic beds, the key factors are the fermentation temperature and ethanol inhibition, both of which have a dramatic effect on the specific rafe of ethanol production. Bed dehydration and its influence on yeast pellet moisture content is also important, since a failure of fermentation may occur if the pellets become too dry (Bauer, 1986). 

Figure 6.1 Factors affecting ethanol production from glucose using baker s yeast (S. cerevisiae) in a gas-solid fluidized bed fermenter. Reproduced from Hayes (1998) with permission.

Hayes, W.A., Ethanol production from glucose by Saccharomyces cerevisiae in an anaerobic gas-solid fluidised bed fermenter, PhD thesis. University of Lincolnshire and Humberside, 1998. 

Rottenbacher, L., Behlau, L. and Bauer, W., The application of infrared gas analyzers for the fast determination of kinetic parameters for ethanol production from glucose, ]. Biotech., 2 (1985a) 137-147. 

Krishnan, M.S., Blanco, M., Shattuck, G.K., Nghiem, N.P and Davison, B.H., Ethanol production from glucose and xylose by immobilized Zymomonas mobtlis GP4(pZB5), Appl. Biochem. Biotech., 84 (2000) 525-542. 

Fermentation is the anaerobic decomposition of organic compounds, basically carbohydrate, into alcohols by the action of bacterial enzymes. Ethanol is the desired product of carbohydrate fermentation, but other alcohols, acids, ketones, and aldehydes can form as by-products. One common example of ethanol production from biomass is the fermentation of com. For illustration, this process will be summarized. 

Ethanol production from ligno-cellulosic biomass... 

Fig. 1. Comparison of ethanol production from whole corn and G/F minus corn. ( ) Whole-corn dextrose ( ) G/F minus corn dextrose (O) whole-corn ethanol ( ) G/F minus corn ethanol.

Ethanol Production from Biomass with Emphasis on Corn , College of Agriculture and Life Sciences, University of Wisconsin, Madison, September 1979. 

In ethanol production from cellulose material, there is a huge amount of lignin left as a by-product. The lignin is a valuable raw material for chemical production in a biorefinery. So in order to reduce the transport cost of the lignin residue, it may be possible to mix it with other raw materials in pellet production in the near future. 

Ethanol production from sugarcane (Saccharum sp.) is one of the easiest and most efficient processes since sugarcane contains about 15% sucrose. The glycosidic bond in the disaccharide can be broken down into two sugar units, which are free... 

Ethanol production from cereal grains such as barley, wheat and com is a much easier process than from cellulose material. The process includes several steps, as listed below ... 

A unique pilot plant for ethanol production from lignocellulose feedstock was inaugurated in O-vik, Sweden in May 2004. The aim of the pilot plant was to develop efficient continuous technologies for the various process steps in ethanol production from forest raw material and other lignocellulosic feedstock. Different raw materials require different conditions during the production process and the process also needs to be optimised for every raw material. Further it was important to demonstrate that large-scale lignocellulose ethanol production was possible... 

Figure 6.7 Scheme of ethanol production from cellulose feedstock... 

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