Process for the production of gaseous methane.

摘要

In a process for producing methane gas by fermentation the methane is recovered by maintaining a reduced pressure in the chamber in which the fermentation process is carried out. Pref. the pressure is between 0 and 0.5 atmospheres underpressure and is maintained e.g. by suction removal of the methane. Process is useful in all methane prodn. units in which waste material such as water purificn. sludge, conc. waste water from biological treatment plants, domestic waste fractions, animal husbandry waste etc. is fermented. Use of reduced pressure (e.g. 1-5 m water column) gives =50% increase in the vol. of methane produced per m3 reactor per day and also increases the degree of conversion of the fermented material to methane. Calculations show that for a given vol. of methane, the reactor vol. required can be reduced by one third, which saves investment costs for the plant.