Ethanol production by fermentation

Bauer, W. and Rottenbacher, L., Utilisation des lits fluidises gaz-solide en bio-technologie application a la production d ethanol par fermentation [Use of gas-solid fluidized beds in biotechnology application to ethanol production by fermentation], Entropie, 124 (1985) 18-23. 

Ethanol production by fermentation at high substrate concentrations see Section 7.6. 

Often the coupling of the membrane unit with the bioreactor results in significant synergy as in the study of O Brien et al. [6.15] on the application of PVMBR to ethanol production, which we discussed in Chapter 3. The required bioreactor volume for the PVMBR system was smaller than that of the conventional system by a factor of 12. Nevertheless, it turns out that the PVMBR-based process is still 25 % more expensive than the classical batch fermentation process in terms of capital costs despite the substantial reduction in the required reactor volume. This cost differential is not only due to the membrane costs, which are, themselves, substantial, but also due to the cost of the additional hardware associated with membrane operation. The application of MBR for the ethanol production by fermentation faces marginal economics, since ethanol is a relatively cheap commodity chemical. 

Sansonetti S, Curcio S, Calabrd V, lorio G, (2009), Bio-ethanol production by fermentation of ricotta cheese whey as an effective alternative non-vegetable source , Biomass and Bioenergy,33(12), 1687-1692. 

Huang, C. F., Lin, T. H., Guo, G. L., Hwang, W. S. (2009). Enhanced ethanol production by fermentation of rice straw hydrolysate without detoxification using a newly adapted strain of Pichia stipitis. Bioresource Technology, 100, 3914—3920. 

Ethanol was one of the first organic chemicals to be prepared and purified. Its production by fermentation of grains and sugars has been carried out for perhaps 9000 years, and its purification by distillation goes back at least as far as the 12th century. Today, approximately 4 billion gallons of ethanol is produced... 

Weuster-Botz, D., Aivasidis, A., and Wandrey, C., Continuous Ethanol Production by Zymomonas mobilis in a Fluidized Bed Reactor. Part II. Process Development for the Fermentation of Hydrolysed B-Starch without Sterilization, Appl. Microbiol. Biotechnol., 39 685 (1993)... 

Lactose is readily fermented by lactic acid bacteria, especially Lactococcus spp. and Lactobacillus spp., to lactic acid, and by some species of yeast, e.g. Kluyveromyces spp., to ethanol (Figure 2.27). Lactic acid may be used as a food acidulant, as a component in the manufacture of plastics, or converted to ammonium lactate as a source of nitrogen for animal nutrition. It can be converted to propionic acid, which has many food applications, by Propionibacterium spp. Potable ethanol is being produced commercially from lactose in whey or UF permeate. The ethanol may also be used for industrial purposes or as a fuel but is probably not cost-competitive with ethanol produced by fermentation of sucrose or chemically. The ethanol may also be oxidized to acetic acid. The mother liquor remaining from the production of lactic acid or ethanol may be subjected to anaerobic digestion with the production of methane (CH4) for use as a fuel several such plants are in commercial use. 

Recent studies have proven ethanol to be an ideal liquid fuel for transportation and renewable lignocellulosic biomass to be an attractive feedstock for ethanol fuel production by fermentation (1,2). The major fermentable sugars from hydrolysis of lignocellulosic biomass, such as rice and wheat straw, sugarcane bagasse, corn stover, corn fiber, softwood, hardwood, and grasses, are D-glucose and D-xylose except that softwood... 

Schorr-Galindo, S., Fontana, A., and Guiraud, J.P., Fructose syrups and ethanol production by selective fermentation, Cum Microbiol., 30, 325-330, 1995. 

FIGURE 11.2 Ethanol production by alcoholic fermentation. From Klass (1994). 

More than twenty years ago, it was recognized that cellulosic biomass, including agricultural residues (such as corn stover, rice and wheat straws, and sugarcane bagasse), municipal wastes (such as yard and paper wastes), and industrial wastes (such as wastes from paper mills), is an attractive feedstock for ethanol-fuel production by fermentation because cellulosic biomass is not only renewable and available domestically in most countries but also available at very low cost and in great abundance. 

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