| 20090032458 | Biogas Producing Facility With Anaerobic Hydrolysis - The present invention relates to a method and a facility for conversion of organic waste into biogas, i.e. a methane containing gas, with an improved efficiency and economy. The method comprises three consecutive steps of: i) digestion of the organic waste in a first reactor; ii) hydrolysis of the digested organic waste in an anaerobic hydrolysis tank; and iii) digestion of the hydrolyzed organic waste in a second reactor; wherein evolved gases are removed from the anaerobic hydrolysis tank. The biogas producing facility comprises a first reactor for holding organic waste for production of biogas by digestion and having an output for digested waste, and an anaerobic tank that is connected to the reactor output for anaerobic hydrolysis of the digested waste and having an output for hydrolysed material that is connected to an input of a second reactor for adding hydrolysed material to the content of the reactor and wherein a gas is passed through the headspace of the anaerobic hydrolysis tank for removal of gases from the digested waste. The anaerobic hydrolysis process and the evaporation and wash out of gases from the hydrolysis tank makes the energy content of material that has not been digested in the reactor easier and immediate available for bacterial digestion and the evaporation and wash out of gases in the hydrolysis tank further reduce inhibition of the bacteria and enhance the biogas production velocity and thus, the hydrolysed material is fed back into a reactor for further bacterial conversion into biogas. Furthermore, the gas that has been passed through the headspace of the anaerobic hydrolysis tank may be cooled in a heat exchanger so that the condensable gases of the gases removed from the anaerobic hydrolysis tank content condense, the condensed water containing the removed gases. | 02-05-2009 |
