Obiettivo To prove the economic viability of producing energy and compost from the heavy organic fraction of urban waste by a new process of dry anaerobic fermentation.1. Scale-up of the existing pilot plant to the present full-scale plant revealed increased difficulties with some of the equipment, notably the press for digested solid mass, as the pressure increases proportionaly to the thickness of the filter cake, and the fluidised bed dryer, as well as the need for complementary equipment such as a steam injector and a treatment unit (a three stage evaporator) for the pressing waste waters at 40 g COD per litre. This has entailed increased costs for the full-scale equipment of a continuous solid-state methane digester.2. For a safe operation of the solid-state fermentor, the aerobic pretreatment in a DANO tunnel appears essential, although it is costly.3. Co-treatment with 25 % sewage sludge is feasible, but uneconomic. It increases the amount of pressing water to be treated, as pressing liquid recycle is no longer possible because the sewage sludge contains 95 % water.4. Heavy metals are present in municipal solid wastes as sulphide derivatives in amounts incompatible with potential European norms for composts. Addition of organic acids eventually produced by acidifying acidogenesis, transforms these sulphides in soluble sulphates. This process is able to decrease the heavy metal content of municipal solid waste in such a way as to yield a compost compatible with European norms. However, this process proves too expensive. 5. The project has however been abandonned for purely administrative reasons, namely the restructuration of the Company, decided by the major share-holders.The organic fraction of urban waste is anaerobically digested at 35-39 % dry solid content and either mesophilic (35 C) or thermophilic (55 C) temperatures. The latter ensures a pathogen-free end-product. Expected daily gas production amounts to 2 to 5 m3/m3 digester. This project features a 450 m3 digester unit considered as representative of a commercial plant including five such units to treat 16 000 tons of organic wastes per year. This representative digester will treat 10 tons waste per day (with a nominal capacity of up to 21 tons per day) producing daily 1 800 m3 biogas containing 55 % methane. The mean residence time of the waste in the digester can be kept at 25 days and possibly below because of continuous seeding with part of the digested material. The space loading rate will be 11 kg COD per m3 of digester per day. 150 m3 biogas is the expected yield from one ton sorted municipal solid waste. The gas will be used to generate electricity in two turbo-generators of 275kW each.The methanation process is part of a urban waste treatment plant including upstream a sorting unit which will sort the material larger than 15 mm and smaller than 60 mm, an aerobic part-composting unit, and downstream a conditioning unit for the anaerobic compost named humotex, produced at 1 600 tons per year at 70 % solids content. Programma(i) ENG-ENALT 2C - Programme (EEC) of demonstration projects relating to the exploitation of alternative energy sources and to energy saving and the substitution of hydrocarbons, 1983-1985 Argomento(i) 1.3 - PRODUCTION AND USE OF BIOGAS Invito a presentare proposte Data not available Meccanismo di finanziamento DEM - Demonstration contracts Coordinatore ARBIOS SA Contributo UE Nessun dato Indirizzo AVENUE PAUL PASTEUR 361 6100 Mont-Sur-Marchienne Belgio Mostra sulla mappa Costo totale Nessun dato
