Methane anaerobic digestion

Ana.eroblc Digestion. Methane can be produced from water slurries of biomass by anaerobic digestion in the presence of mixed populations of anaerobes. This process has been used for many years to stabilize municipal sewage sludges for purposes of disposal. Presuming the biomass is all cellulose, the chemistry can be represented in simplified form as follows ... 

Fig. 4. Microbial phases in anaerobic digestion A, hydrolysis B, acidification C, methane fermentation.

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

An anaerobic digester is a no-recycle complete mix reactor. Thus, its performance is independent of organic loading but is controlled by hydraulic retention time (HRT). Based on kinetic theoiy and values of the pseudo constants for methane bac teria, a minimum HRT of 3 to 4 days is required. To provide a safety factor and compensate for load variation as indicated earlier, HRT is kept in the range 10 to 30 days. Thickening of feed sludge is used to reduce the tank volume required... 

Recovery of Riologieal Conversion Products Biological conversion produces that can be derived from solid wastes include compost, methane, various proteins and alcohols, and a variety of other intermediate organic compounds. The principal processes that have been used are reported in Table 25-64. Composting and anaerobic digestion, the two most highly developed processes, are considered further. The recovery of gas from landfills is discussed in the portion of this sec tion dealing with ultimate disposal. 

Anaerobic digestion Methane gas Shredding, air separation Technology on laboratory scale only... 

These tanks at a water treatment facility are used to generate a mixture of methane and carbon dioxide by anaerobic digestion of sewage. The methane produced provides much of the power needed to run the facility. 

Hickey, R.F., Vanderwilen, J., and Switzenbaum, M.S., The effects of organic toxicants on methane production and hydrogen gas levels during the anaerobic digestion of the waste activated sludge, Water Res., 21, 1417-1427, 1987. 

Juarez-Rodriguez et al. applied the sludge derived from anaerobically digested cow manure in the production of biogas (methane-air), to maize (Zea mays L.) cultivated in a nutrient-low, alkaline-saline soil with EC 9.4 dS m 1 and pH of 9.3. The results showed that the C02... 

HYAN [Hybrid anaerobic] A process for treating the supernatant liquor from sewage sludge treatment plants by anaerobic digestion. The methane produced is burnt to provide heat for the treatment plant and to destroy odors. Developed by a Canadian consortium and operated at the Lakeview Water Pollution Control Plant, Mississauga, Ontario, from 1991. 

Valorga A process for treating household waste by anaerobic digestion with the production of methane. Developed in the 1990s at the Languedoc University of Science Technology. Waste Manag. Environ., 1996, 6(3), 40. 

Biological conversion via anaerobic digestion is currently being practiced, resulting in methane that can be processed to hydrogen by conventional steam reforming processes. 

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