Obiettivo The project aims at demonstrating the reliability and the profitability of an innovative controlled composting device in a closed well-insulated reactor allowing the recovery of waste heat resulting from the condensation of the water and of the saturated exhaust air. This waste heat is innovatively recovered as low-joule heat through heat pumps. 15 m3 of compost will be produced weekly each in a 7-day batch composting cycle (750 m3/year) from organic household waste (separately collected together with green matter).The plant will produce (over a 6 month-heating period per year) 112.800 kWhth (9,7 TOE) and have a payback period of 11 years (related on actualized investment costs per 1.000 ton capacity-plant and only considering heat production and waste-prevention). Missing aspects : CO2 and H2O and compost production.From January 92 to January 93, 429,59 tons of separately collected organic household-waste were composted i.e. 34% of the foreseen total mass. This was principally due to the voluntariness of the population participation in separate organic waste collection.In the energy balance an energy-output of 99,8 kWhth for an electrical energy input of 45,7 kWhel has been achieved.As the price ratio of thermic energy and electric energy is 1 to 5, the net costs per kWhth arise to more than 1 Flux.It is important to mention that the recovered 21.200 KWhth is the energy claimed by thermostatic heat regulation of the greenhouse. It is evident that as soon as outside temperature level reaches 12 to 15 deg. C there is no more demand for energy supply.On the other hand the valorizable energy production in the composting box does not occur during the whole composting process. Especially phase II and IV of the process generate suitable temperature levels (minimum 20 deg. C up to 30 deg. C) to be converted in 40 to 50 deg. C hot water to be used for heating the greenhouse.To conclude it is to say that to improve the economic viability of such a project a technical redesign is necessary;Especially concerning :- the heating mode of the greenhouse- a larger amount of waste to be treated- the use of air/air heat pumps- the use of CO2 produced as growing factor.The household waste is granulated down to less than 35 mm and, if necessary, brought into an open, crumbly structure by incorporation green cuttings. Using wheeled loaders, the mixture for composting is loaded loosely on perforated steel base plates in the totally enclosed, approximately 50 m3 composting box. Then the front door is closed and the encompassing inflatable door valve ensures that the box is hermetically sealed.The ventilation is switched on and in the "Automatic" position air is fed in according to the ambient values measured on the top of the reactor approximately 1 m abpive the composting material. The intensity of the ventilation during the intensive decomposition phase is computer controlled according to the oxygen requirement or the CO2 production and the temperature of the decomposition material. During the biological decomposition of the substance, which takes place readily, the operating temperature is about 60 deg. C. As the composting box is thermally insulated, all of the biologically produced heat can be passed via an air/water heat exchanger where the vapour saturated air is cooled down and the water condensed out. The condensing energy is transferred to the cooling-water, which heatend-up, is pumped to the heat-pumps and utilized technologically.As soon as the biologically useful organic mass and the vaporizable water are removed from the decomposing material, the oxygen demand is existing but very low (decomposition grade II) topsoil. It takes about 7 days to reach this condition.The box is then opened, the finished product removed, using wheeled loaders in the same way as when loading, and then stored loose on open piles for about 8 to 12 weeks keeping on decomposting, and finally achieving a classification grade IV. Now it is available after screening as a substitute for peat or packed in air permeable sacks after producing susbtrates ready for marketing (e.g. by adding fertilizers or sorbent materials). Programma(i) ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989 Argomento(i) 1.1 - COMPOST AND FERTILIZERS PRODUCTION Invito a presentare proposte Data not available Meccanismo di finanziamento DEM - Demonstration contracts Coordinatore ADMINISTRATION COMMUNALE DE PETANGE Contributo UE Nessun dato Indirizzo PLACE J.F. KENNEDY B.P. 23 4701 Petange Lussemburgo Mostra sulla mappa Costo totale Nessun dato
