Proceedings

The use of anaerobic digestion (AD) to treat the organic content of residual MSW and similar organic residues from commercial wastes is becoming an increasingly significant part of the UK Waste Strategy, as it is already in Europe. In selecting a suitable digestion process, whether wet or dry process, the characteristics of the wastes to be treated are of primary importance, if stable operation of the digester is to be achieved and a stabilised digestate produced. Optimising biogas production generates increased revenues to support and enhance the financial viability of an MBT AD project. The composition of the waste will influence both the type of front-end pre-treatment required prior to digestion and the quality of the digestate compost like output (CLO) and its ability to be used for non-landfill purposes.

Different digestion processes have significantly different parasitic power loads, which impact markedly on the net power generated and power sales revenue. In the event of no suitable non-landfill use being identified for the CLO, use as a biomass fuel to provide renewable power qualifying for ROCs can potentially provide an additional source of revenue.

KEYWORDS
Anaerobic digestion, residual wastes, MBT, energy recovery, CLO