Ethanol Economic data

Compared to other technologies for alcohols production (e.g. ethanol fhom biotechnology), this new approach for the production of methanol-higher alcohol mixtures and its related economic data look rather promising for the near future. The alcohols blend produced at demonstra-... 

Ethanol production. Economic data (France conditions, mid-1986)... 

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. 

The data above enable us to make some rough estimates of costs associated with two processes (i) ACID, that is aspen wood-autohydrolysis-caustic extraction-acid hydrolysis-fermentation-distillation and (ii) ENZYME, that is aspen wood-autohydrolysis-caustic extraction-enzymatic hydrolysis-fermentation-distillation. For purposes of comparison, the product in both cases will be assumed to be 10 million gallons of 95% ethanol per year, a minimum economic size. 

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. 

Aqueous solutions of these alcohols occur when sugar solutions are fermented and may be separated by distilling the mixtures. It is a common, economically valuable process for manufacturing potable liquors and for producing industrial alcohol from fermented molasses solutions or pulp mill wastes. One of the authors (A.Y.M.) reports that design and operation of these columns is hampered by lack of vapor-liquid equilibrium data, especially for making potable liquors, where small amounts of the alcohols other than ethanol greatly affect the flavor and, therefore, the products marketability. 

In the recoveiy of ethanol and many other otganic solutes from aqueous solution, coextraction of water has a large effect on the process economics. Solvents may be compared hy plotting the selectivity (k = separation factor between ethanol and water) versus the solvent capacity for ethanol, expressed as Kff. Figure 15.2-6 la such a plot for extraction of ethanol from relatively dilute aqueous solution by many different solvents.3 This figure includes data fiom Roddy 35 Souissi and Thyrion,37 and Munson and King. 

An exhaustive economic analysis for the production of cellulose nanowhiskers as a coproduct in an ethanol biorelinery and an ASPEN Plus-based process model (http //www.aspentech.com/core/aspen-plus.cfm) was developed to evaluate ethanol production from wheat straw. All the collected data on cellulose nanocrystals in terms of production, characterization, and application suggest that this nanomaterial could be easily extrapolated to bioethanol production (Duran et al. 2011). 

The worked example for the extraction of material from a solid matrix with marginally subcritical carbon dioxide complements a similar example for the extraction of an ethanol/water solution given in an earlier paper [1]. The intention of the example was to illustrate the way in which a proposed near-critical extraction process can be costed from bench data and to highlight aspects in the design which are important in dictating the energy consumption and overall economics of such a process. 

Winston SJ, Solar Energy Information Data Bank (1981) Ethanol fuels use, production economics, 1st edn. US Government Printing Office, Golden... 

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