Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Chlorine corrosion reduction by coal change in a 80MWth CFB plant of EVO AG, Germany

Meat and bone meal, (MBM) is produced in the rendering plants where animal offal and bones are mixed, crushed and cooked. In response to the recent outbreaks of BSE the EU has issued a temporary ban on animal meal in feed for all animals intended to human consumption. Firing MBM in power plants is attractive because of the payment to the power companies for destroying this waste. Its land filling is expensive and may cause serious hygienic problems, and finally this waste is destroyed through chemical reactions producing for example methane and carbon dioxide.

Combustion of MBM in power plants contains high operational risks because of its high chlorine content. Chlorine and alkali metals form alkali chlorides, which vaporise from the fuel during combustion. These compounds act as Cl carriers to the superheaters leading to serious and expensive boiler damages (corrosion, hard deposits) as observed in EVO AG:s 80MW CFB after co-firing MBM with German hvb coal. MBM is also rich with calcium and phosphor, which can strengthen the operational problems started by alkali chlorides.

In this project Cl deposition was prevented by co-firing MBM with coals containing highly reactive aluminium silicate. The original coal co-fired with MBM contained aluminium silicate deactivated partly with potassium. Therefore its protecting power was low. This result can be applied to MBM and other similar waste planned to be combusted in EVO AG s CFB and elsewhere.

Informations connexes

Reported by

Energiaversorgung Offenback AG
André Strasse, 71
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