Industrial boilers burn wood fuel for heating the site or to generate energy. However, by incinerating waste wood, plants must not exceed their emission limit values. Most boilers require Continuous Emissions Monitoring Systems (CEMS) to monitor and control emissions to atmosphere.
It is possible to burn waste wood from wood offcuts, packaging waste, demolition waste, construction waste, shavings or even saw dust to generate heat under current environment agency regulations. The benefit of burning waste wood generates energy for heating or other industrial processes.
When virgin timber is mixed with waste timber or any other waste, the mixed load is classed as waste wood. Waste wood is subject to the Industrial Emissions Directive (IED).
Waste Wood Grades
The Wood Recyclers Association specifies waste wood into Grades A, B, C & D. Each grade is subject to a regulatory framework and helps determine the requirement for Continuous Emissions Monitoring Systems. Expand the diagram below to understand your regulatory requirement.
Industrial Emissions Directive (IED)
In relation to burning wood, the IED covers combustion plant >50MW and incineration of non-exempt waste wood >3T/hr. Both configurations require a Part A permit from the Environmental Agency (EA) and a complete MCERTS certified Continuous Emissions Monitoring System (CEMS) is required.
If the plant is burning non-exempt waste wood at <3T/hr, then it is a Small Waste Incineration Plant (SWIP), however, Chapter IV still applies and therefore you will need the same monitoring and controls as a Waste Incineration Directive (WID) installation.
In summary, Grades of wood C & D are subject to the IED and therefore require a complete MCERTS certified CEM System. Grade B wood is only required to meet the requirements of IED if the thermal input of the boiler is >50MWth.