(BE1006019-A3)      Degradable organic waste is anaerobically decomposed in a areactor from which biogas is extracted. The reactor contains ana ctive, anaerobic, methanogene biomass. Fermentation occurs without any mixing. The waste is supplied to the reactor as a semi-solid or solid organic substrate in the top of the reactor. A phase sepn. into liq. and solid occurs in the power part of the reactor. The liq. phase is removed before fresh substrate is supplied. A max. amt. of solid phase is retained. After removal of the liq., the solid phase is removed from the reactor from the reactor in an amt. of at least one third of the entire reactor content. The removed fraction is thoroughly mixed with fresh substrate as inoculum.    USE/ADVANTAGE -   The process treats the organic fraction of domestic or biological waste or similar organic sludges of industrial origin. The process provides efficient treatment for organic waste of all types not merely dry solid substrates and the fraction which can be easily hydrolysed.    (US5389258-A)      Anaerobic decomposition of organic degradable waste takes place in a reactor releasing bio-gas. Semi-solid or solid waste is supplied to the reactor top. The waste separates into liq. and solid phases during fermentation without any mixing. The liq. collecting in the base is discharged before fresh waste is added. About 1/3rd of the solid phase is removed and thoroughly mixed with fresh waste and then returned to the reactor.    USE/ADVANTAGE -   To form an active anaerobic methanogenic biomass. The reactor can produce a high output of decomposed waste without any internal mixing required.    (EP577209-B1)      Degradable organic waste is anaerobically decomposed in a reactor from which biogas is extracted. The reactor contains an active, anaerobic, methanogene biomass. Fermentation occurs without any mixing. The waste is supplied to the reactor as a semi-solid or solid organic substrate in the top of the reactor. A phase sepn. into liq. and solid occurs in the lower part of the reactor. The liq. phase is removed before fresh substrate is supplied. A max. amt. of solid phase is retained. After removal of the liq., the solid phase is removed from the reactor in an amt. of at least one third of the entire reactor content. The removed fraction is thoroughly mixed with fresh substrate as inoculum.    USE/ADVANTAGE -   The process treats the organic fraction of domestic or biological waste or similar organic sludges of industrial origin. The process provides efficient treatment for organic waste of all types not merely dry solid substrates and the fraction which can be easily hydrolysed.