COMBINED TREATMENT OF MUNICIPAL SOLID WASTE AND SEWAGE SLUDGE BY BIOMETHANATION TO PRODUCE A FERTILIZING SOIL CONDITIONNER

Información del proyecto

Identificador del acuerdo de subvención: BM.-00536-85

Proyecto cerrado

Fecha de inicio 1 Abril 1986

Fecha de finalización 31 Diciembre 1989

Financiado con arreglo a

• Programme (EEC) of demonstration projects relating to the exploitation of alternative energy sources and to energy saving and the substitution of hydrocarbons, 1983-1985

Coste total

€ 2 440 394,00

Aportación de la UE

€ 109 818,00

Coordinado por

SNAMPROGETTI SPA
Italy

Objetivo

The project aims to demonstrate the possibility to integrate in a single plant, the production of energy by biomethanation and the production of a fertilising soil conditionner by stabilisation of the mixture of the organic fraction sorted out of municipal solid waste on the one hand, and sewage sludge from municipal wastewater treatment plants, on the other hand.
The demonstration plant will be installed in the municipality of Asti in the region of Piedmon, Italy.
The innovative aspect consists of integration of appropriate unit operations, including a continuous solid-state methane digester ( VALORGA) for these dual treatments and dual productions.
The energy production and saving is expected to amount to 616 tep per year. The simple payback period is calculated at 5 years by comparison with an alternative aerobic stabilisation solution.
Only some works concerning the design phase have been carried out : partial definitive sesign, definition of design parameters, investigation to optimise the use of the obtained products according to a modification of the original site.
The lack of national and regional planning permission to build the plant has constrained the contractor to abandoned the project.
The central part of the innovative technology consists of a methane digester constructed in concrete (mainly), well insulated, of 1200 m3 capacity, able to withstand 1 bar internal pressure produced by the mixed liquor in the digester.
The methane digestion will be operated under the following conditions : mesophilic temperature (33-35 deg. C), mean residence time of 15 days, daily loading rate of 10 kg dry matter per m3 of digester volume. Movement of the mixed liquor within the digester and to leave the digester will not be done mechanically but by gas recirculation and/or gas pressure. The daily biogas production is expected to amount to 4400 m3 (specific biogas production rate of 4 volumes of biogas per volume of digester per day) of a lower calorific value between 5 and 5. 3 Mcal/m3. The yield is expected to be 120 to 140 Nm3 biogas per ton organic matter treated.
The conversion is expected to be between 40 and 50% on an organic matter basis.
Upstream within the innovative technology, the municipal solid waste will be crushed and sorted out in three fractions.
After removing ferrous material and large pieces of cardboard, plastics, textiles etc. , an organic fermentescible fraction will be obtained. By organic fraction is meant the fraction below 40 mm average size and separated ballistically from the heavy inert small particles. The organic fraction resulting from 50 tons municipal solid waste will be mixed with 10 tons of sewage sludge from municipal wastewater treatment plants with a content of 8% total solids, on the one hand, and liquid and bacterial inoculum recycled from the methane digester on the other hand. The mixture constitutes a substrate biomass with a content of 30% total solids.
Downstream, the mixed liquor effluent from the methane digester will be treated in a screw press to increase its total solids content. Part of the liquid portion resulting from this process will be heated at 75 deg. C and recycled upstream of the methane digester. The excess liquid part is deposed of in a municipal wastewater treatment plant.
The biogas produced will be stored at low pressure in a hydraulic gasholder. Part of the biogas will be recycled for heating purposes in the biomethanation process. The remaining part of the biogas will be used outside the plant, eventually to produce electricity.
The dried final sludge produced by the screw press, will be crushed and sieved below 20 mm in two fractions : below 10 mm and between 10 and 20 mm, yielding two fertilising soil conditioners of different quality for different uses. The lower size fraction has the highest value and will be used in horticulture.
Monitoring will include mass balances around the process, quality and composition of influent municipal solid waste and sewage sludge, temperatures, every balances and automatic operation control.

Ámbito científico (EuroSciVoc)

Este proyecto aún no se ha clasificado con EuroSciVoc.
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Programa(s)

• 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

Tema(s)

• 1.3 - PRODUCTION AND USE OF BIOGAS

Convocatoria de propuestas

Datos no disponibles

Régimen de financiación

DEM - Demonstration contracts

Coordinador

SNAMPROGETTI SPA

• Aportación de la UE: Sin datos
• Dirección: Viale Alcide De Gasperi 16 ; 20097 SAN DONATO MILANESE ; Italia
• Coste total: Sin datos