Thermochemical processes

Thermochemical methods are employed for either significantly reducing the sludge solids content, or pre-treating sludge upstream of anaerobic digestion (AD) to increase the biodegradability of the organic carbon. When operated at elevated temperatures, i.e. for solids destruction rather than for AD pre-treatment, they provide energy recoverable either as heat (for oxidative processes) or a combustible gas or liquid (non-oxidative processes).