Ethanol carbohydrate content

High yields of fermentable sugars in Jerusalem artichoke have been reported in Canada. The sugar yields obtained from tubers of 6.2 to 8.6 t-ha 1 under prairie conditions compared favorably to the yield of 4.9 t ha 1 obtained with sugar beet (Stauffer et al., 1981). Theoretical ethanol yields from Jerusalem artichoke grown in Manitoba were given as 4,580 kg ha-1 (5,780 1-ha-1) for tubers (of fresh weight 42,000 kg-ha 1 and carbohydrate content 7,088 kg ha-1) and 1,920 kg ha-1 (2,423... 

Compositional variability can have a significant impact on biomass conversion process economics. The large effect (i.e., at least 0.30/gal ethanol) of observed compositional diversity on process economics is shown in Fig. 33.19 and is primarily due to the fact that the maximum theoretical product yield is proportional to feedstock carbohydrate content (Fig. 33.20).131 Yield is the major economic driver for the technoeconomic model used to assess the economic impact of composition on minimum product selling price,130 as can be seen from the data in Fig. 33.21. 

Fig. 33.21. Relationship between carbohydrate content of feedstock and ethanol yield per ton of input...

Fermentation proceeds via the development of microorganisms that the food industry controls and corrects to obtain the desired results. The main substratum that is transformed is made up of carbohydrates, which may undergo various types of fermentation, with the production of more simple substances that are very important in the determination of the quality of the final product. In some cases, the formation of some substances may indicate undesired processes. There is, therefore, the need to intervene rapidly so that the necessary corrections may be made to the process. Fast analytical methods are required that can in most cases ascertain the content of various sugars, organic acids, glycerol, and alcohols (for example, methanol, ethanol, higher alcohols). 

Alcohol is distilled up to a content of 96% in one or more stages. About 1 % of ethanol consists of fusel oils (degradation products of amino acids) which can be used as solvents for lacquers and resins. Solids from the processed liquor containing proteins, carbohydrates, mineral salts, riboflavin and other vitamins are used in poultry, swine and cattle feeds. C02 and H2 produced in butanol-acetone-butyric acid production can be used for the chemical synthesis of methanol and ammonia, or are burned. 

The first law of thermodynamics allows us to rate foods in terms of their energy contents. These are really AH of combustion values. Thus, carbohydrates, fats, proteins, and ethanol yield approximately 4, 9, 4, and 7 kcal/g, respectively when combusted. A normally active person requires between 2000 and 2500 kcal/day in foodstuffs to function normally. Persons doing heavy work may require as much as 5000 kcal/day or more. 

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