Anaerobic digestion, commercial

Table 37. Potential Methane Production from Commercial U.S. Anaerobic Digestion Systems...

J. H. Ashworth, Y. M. Bihun, and M. La2ams, Universe of U.S. Commercial-Scale Anaerobic Digesters Results of SERJ/ARD Data Collection, Solar Energy Research Institute, Golden, Colo., May 30,1985 J. H. Ashworth, Problems With Installed Commercial Anaerobic Digesters in the United States Results of Site Visits, Rev. ed.. Solar Energy Research Institute, Golden, Colo., Nov. 6, 1985. 

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. 

In the early 1980s, there was a large increase in the number of commercial anaerobic digestion plants constructed in the United States, particularly advanced technology systems for industrial wastes (c/. Klass, 1983). Several of the new digesters were of the fixed-film or upflow sludge blanket types. Full-... 

FuelCell Energy NG, anaerobic digester gas MCFC 1.5-300 Stationary Commercial... 

HydrogenSource NG, methanol, anaerobic digester gas PEMFC Stationary/ transportation Commercial... 

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