MCPD 2025: Are your boilers ready?

THE MEDIUM Combustion Plant Directive (MCPD) has been in place since December 2018 to limit pollutant emissions, such as nitrogen oxides (NOx) and sulphur dioxide (SO²), for new medium combustion plants (1-50 MW). Since January 2025, it has also applied to existing (pre-2018) plant between 5 and 50 MW.

Originally introduced at EU level and now retained in UK law, MCPD was drawn up to meet the regulatory gap between large combustion plants above 50 MW, covered by the Industrial Emissions Directive (IED) and smaller appliances (heaters and boilers below 1 MW) covered by the Ecodesign Directive.

It therefore applies to almost all industrial boilers between 1 and 50 MW. Since December 2018, all new plant falling under its remit have been required to be registered and comply with published Emission Limit Values (ELVs). Since January 2025, existing plant above 5 MW should be registered and compliant with its emission limit values. Existing plant between 1-5 MW will be required to meet their ELVs from January 2030.

Does your boiler fall within scope?

From our experience, awareness of MCPD obligations remains inconsistent. Many plant operators are unclear where they stand when it comes to compliance. To help clarify, we have summarised the key requirements below.

As a first step, an operator must identify if its combustion plant falls under the MCPD directive and understand the requirements that apply to its MCP. If the plant is not covered by a permit, it must be registered and brought into compliance with ELVs through regular monitoring and record-keeping. Limits apply for nitrogen oxides (NOx), sulphur dioxide (SO²) and dust to meet air quality requirements. 

Ongoing emission monitoring and data submission is required to confirm continued compliance. Measurements are required periodically, depending on plant size and regulator: 

• Plants > 20 MW net rated thermal input: on registration, then annually.
• Plants < 20 MW net rated thermal input: on registration, then every three years.
• Measurements will only be required for pollutants which have an emission limit value laid down (NOx, SO², dust), as well as CO for all plants.

In the UK, operators must report to regulators such as the Environment Agency, Natural Resources Wales, The Northern Ireland Environment Agency (NIEA) and Scottish Environment Protection Agency (depending on location) and provide emissions data, operational hours and any non-compliance events. 

Mitigating non-compliance risk

If at any time levels are above those stipulated, it is the responsibility of the operator to take measures to ensure non-compliance is kept to a minimum and rectified swiftly.

In response, we developed our UltraNOx burner range to reduce NOx at source. Depending on the capacity required, we have three burner types available (S, T and E). In typical boiler applications, the burners can achieve levels from 40 mg/Nm³ at 3% O₂ without flue gas recirculation (FGR), providing headroom for further reduction if required.

We are seeing more customers requiring solutions for existing boilers to comply with NOx limits under MCPD and, in some cases, achieve lower emission levels

Case study: modernising an existing boiler

For example, a global independent beverage solutions provider had an existing Cochran boiler which, following an audit, was found to be non-compliant with MCPD.

Following a site survey, we established that the existing equipment was suitable for upgrading, moving from previous generation burner technology to our latest UltraNOx combustion technology, whilst also replacing obsolete control equipment to futureproof the boiler against evolving emissions requirements.

Our solution not only met the requirements of MCPD, but provided improved boiler efficiency, reduced operational noise and improved plant flexibility. The upgrade delivered a threefold reduction in NOx emissions and doubled the burner turndown ratio.

Looking ahead

So, what should your next steps be? With the introduction of this legislation and with increasing scrutiny and global action on reducing emissions, it is essential that operators fully understand their obligations. Whether this requires burner and plant upgrades or complete boiler replacement to bring existing systems into compliance, early assessment and intervention can help operators avoid disruption and protect long-term plant resilience.

Christopher Callaghan is aftermarket support manager at Cochran

For more information: 

https://www.cochran.co.uk

Tel: +44 (0)1461 202111