Renewal of environmental approval for biomass-fired plant

The boiler system run by the energy producer Verdo comprises of two 80 MW chip-fired boilers, which were converted to biomass in 2007-2009.

Because of tightened emission standards for CO and NOX in new BREF (Best Available Techniques Reference) documents, the plant needs to renew its environmental approval.

COWI has supplied a prioritised list of possible emission improvement measures, which include optimising and modifying existing facilities and establishing chemical flue gas scrubbing.

The activities in the analysis phase included operational trials, modelling of heat balances and creating CFD models for the boiler room. The testing phase covered setup, regular coordination and documentation of the testing programme to investigate the potential for emission improvements to the existing plant.

The testing phase produced around a 50% reduction in CO, but the provisional conclusion is that chemical NOX reduction is still needed.