Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Sewage sludge gasification trials using a spouted fluidised bed gasifier

EMC's gasification test programme examined the use of spouted fluidised bed gasification. A programme of ten gasification trials was carried out in the EMC 350 kW spouted fluidised bed gasifier using four sources of sewage sludge samples as the feedstock. The impact of parameters, such as fuel conditioning, co-firing with coal and gasifier bed temperature on factors was investigated.

The spouted bed gasification test programme confirmed that the thermally dried sewage sludge pellets were very reactive and significant operational problems were encountered when the dried sludge pellets were fired as a single fuel. This was postulated to be attributable to the vigorous spouted bed environment. Pre-treating the sludge pellets with water and co-firing with a higher calorific value support fuel, however, improved the gasifier operability significantly.

Improvements to fuel gas quality were also attainable by increasing the gasifier temperature. The results have also demonstrated the importance of selecting co-firing fuels, which are compatible in terms of reactivity and ash melting characteristics. For co-firing applications, the ideal scenario would be to operate under optimal gasification conditions for the primary fuel and select a secondary fuel, which has a similar or higher reactivity, low levels of contaminants, complimentary calorific value and comparable or higher ash melting characteristics.

Reported by

EMC Environment Engineering Ltd.
Floor 3, Aspen Building, Vantage Point Business Village, Micheldean
GL17 0DD Glos
United Kingdom
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