Patent DE-102011120888-B3 (DE)
Title: Degradation of biogenic material, comprises carrying out thermo-mechanical pulping and recycling food ingredients and other organic waste including fermentation residues in multistage system by homogenizing in mixing- and grinding system
Inventor: WALTER MICHEL
IPC: C12M1/107
Filed: 2011-12-09
Granted: 2013-05-08
Abstract: Degradation of biogenic material, comprises: carrying out the thermo-mechanical pulping and recycling the ingredients of food residues and other organic waste including the fermentation residues in a multistage system. The raw material to be recovered are homogenized in a rotating mixing- and grinding system (1), diluted with water from the circulating system and a continuously operating thermo-compression hydrolysis system (2) at 130-150[deg] C. The biogas produced in the anaerobic operating step floats in a floating bed reactor and has a methane content of >= 80%. Degradation of biogenic material, comprises: carrying out the thermo-mechanical pulping and recycling the ingredients of food residues and other organic waste including the fermentation residues in a multistage system. The raw material to be recovered are homogenized in a rotating mixing- and grinding system (1), diluted with water from the circulating system and a continuously operating thermo-compression hydrolysis system (2) at 130-150[deg] C. The biogas produced in the anaerobic operating step floats in a floating bed reactor and has a methane content of >= 80%. The remaining organic substance degraded in the aerobic operating stages equipped with a membrane ventilation system in the downstream. The hydrogen-consuming methane production compared to the acetate-consuming methane formation amplifies an increase in the hydrogen concentration in the substrate by hydrogen-forming microorganisms. The sewage sludge is used as an initiator and mediator for enhanced hydrogen-consuming methane formation. The remaining coarse solids are separated, dried and pelletized by separation according to thermo-compression hydrolysis and the pre-hydrolysis. The separation of the resulting centrifugate is carried out using water, to a dry matter content of 3-5% and a methane content of maximum of 2500 mg/l, and a working temperature is adjusted to 30-55[deg] C, where acid forming microorganism cultures are inoculated in a hydrolysis tank such that the acids required for the production of biogas are formed in anaerobic conditions, and a pH is adjusted to 6.5-7. The promotion of the pre-hydrolyzed substrate is carried out in the floating bed reactor for anaerobic biogas production at a temperature of 35-50[deg] C in the up flow principle. The carbon-containing cleavage products and microorganisms, which are discharged from the reactor, are concentrated by the external insertion of a micro- or ultra-filtration stage in the end of the anaerobic reactor or many reactors connected in parallel or in series, such that long chain cleavage products, and microorganisms are returned to the biogas process. The separated filtrate is further purified on a floating bed column (8) under aerobic conditions and then subjected to a thermization at 60-75[deg] C for killing the microflora and is processed in an ultrafiltration system and a downstream, two-stage reverse osmosis system. The residual gas e.g. methane, carbon dioxide, hydrogen sulfide, which are remaining in the liquid are removed via an upstream vacuum separator from the liquid at a reduced pressure of -0.2 to -0.4 bar before ultrafiltration. An independent claim is also included for plant containing a floating bed reactor column with anaerobic and aerobic steps and integrated membrane operating stages for recycling of organic residues in the degradation step and recycling of the treated water in the treatment process, comprising at least a separation device for non-organic impurities as a coarse separation, a rotating mixing- and grinding system with homogenizing, a thermo-compression hydrolysis system, a separation plant, such as screw pressing screws, decanter or vibrating sieve, a drying and pelletizing plant (5), an enzymatic pre-hydrolysis by incubation with microorganisms at 55[deg] C, an up flow anaerobic floating bed reactor (6), an aerobic operating step, which is designed as floating bed reactor and which is equipped with floating bodies with a density of 0.95-0.98 g/cm 3>and a diameter of 50-250 mm, a microfiltration, an intensive ventilation for air entry into the aerobic up flow floating bed, a thermization system for thermal treatment of the effluent from the aerobic floating bed reactor, a degassing system with carbon dioxide removal to improve the ultrafiltration performance, an ultrafiltration system, a return of the resulting concentrate into the anaerobic floating bed reactor, a transmission of the filtrate to a reverse osmosis, a reverse osmosis system to concentrate the mineral content and recycling of the reverse osmosis water to thermocompression hydrolysis and production of pure water, and a membrane-intensive entry and ventilation system.