GovWire

1. Who this guidance is for

This guidance on emerging techniques is for combustion plant within the scope of the:

• Industrial Emissions Directive (IED)
• best available technique (BAT) reference (BREF) documents
• Medium Combustion Plant Directive (MCPD)

The environmental regulators developed this guidance as there are no ELVs for hydrogen combustion in the legislation. The guidance is meant to set out what the regulators expect until there is enough uptake for them to understand what is achievable for air pollutant emissions. When appropriate, they will develop BAT documents and associated emission levels (AELs) which will guide the permitting process in the legislation.

Unlike combustion of conventional fuels, combustion of hydrogen produces no direct emissions of carbon dioxide. Therefore, it is a credible avenue for low-carbon combustion processes. However, it is important not to compromise local air quality in the transition to low-carbon fuels.

This guidance sets out ELVs for oxides of nitrogen (NOx) and carbon monoxide (CO), as appropriate, for combustion of hydrogen within the scope of:

• plant covered by the MCPD, referred to as medium combustion plant (MCP)
• plant covered within the scope of Chapter III of the IED, referred to as large combustion plant (LCP)

The combustion of hydrogen results in a change in the flue gas volume. Therefore, you need to use a correction factor to achieve equivalence with ELVs defined for natural gas on a mass per unit volume basis, as described in ETN Position Paper, 2022. Figure 2 in the ETN Position Paper provides a range of correction values between 1.3 and 1.5, further calculations a range of 1.36 to 1.39, and the value of 1.37 as optimal. At 100% hydrogen substitution, this correction factor of 1.37 is applied to ELVs for combustion of natural gas, as set out in the MCPD and IED, to get ELVs for combustion of hydrogen.

2. Definitions of existing, new and new-new plant

In this guidance, the following definitions apply to hydrogen combustion plant.

Existing

For LCP, existing plant means plant with a permit for combustion of a conventional fuel that was put into operation before 8 January 2014. This is specified in IED Article 30(2).

For MCP, existing plant means plant put into operation before 20 December 2018. This is specified in MCPD Article 3(6).

New

For LCP, new plant means plant with a permit for combustion of a conventional fuel that was put into operation on or after 8 January 2014 (as specified in IED Article 30(2)), but before 1 January 2025.

For MCP, new plant means plant put into operation after 20 December 2018 (as specified in MCPD Article 3(6)) but before 1 January 2025.

New-new

New-new means plant with a permit for combustion of hydrogen or a hydrogen and natural gas blend put into operation after 1 January 2025.

Changing from one definition to another

In certain circumstances, such as substantial refurbishment, existing plant will be redefined as new-new. It may be necessary for plant to go through a lot of retrofitting to transition to hydrogen firing. For guidance on refurbishment, contact your regulator.

3. Minimum ELVs for hydrogen as a single fuel

Table 1 (for existing plant) and Table 2 (for new plant) give the NOx ELVs you must meet for combustion of hydrogen by plant and thermal input.

In this guidance, for all plant the reference conditions for ELVs are:

• 273.15K
• 101.3kPa
• dry
• 3% oxygen for boilers
• 15% oxygen for gas turbines and engines

Table 1. ELVs for existing plant using 100% hydrogen fuel

Table 2. ELVs for new plant using 100% hydrogen fuel

Plant type and thermal input	NOx ELV (mg/Nm3)
Gas turbines: greater than or equal to 50MWth	68.5
Boilers: greater than or equal to 50MWth	137
Gas engines: greater than or equal to 50MWth	102.8
Gas turbines: greater than 5MWth and less than 50MWth	68.5
Boilers: greater than 5MWth and less than 50MWth	137
Gas engines: greater than 5MWth and less than 50MWth	130.2
Gas turbines: greater than or equal to 1MWth and less than or equal to 5MWth	6  View the original news story Related Articles Scroll Back To Top 📄More Articles Guidance: Hydrogen combustion: comply with emission limit valuesMonday, 21 Oct Guidance: Medium combustion plant (MCP): comply with emission limit valuesThursday, 1 Sep Guidance: Medium combustion plant (MCP): comply with emission limit valuesWednesday, 28 Dec Guidance: Medium combustion plant (MCP): comply with emission limit valuesTuesday, 7 Mar Guidance: Medium combustion plant (MCP): comply with emission limit valuesTuesday, 23 Jul Comments Scroll Back To Top ✎Write Comment We don't have any comments for this article yet. Why not join in and start a discussion. Write a Comment Scroll Back To Top Your name: Your email: Comments: Post my comment  Sponsored Advert   Ministerial Departmental News   PM's Office, 10 Downing Street   Cabinet Office   Department for Business, Innovation and Skills   Department for Communities and Local Government   Department for Culture, Media and Sport   Department for Education   Department for Environment, Food and Rural Affairs   Department for International Development   Department for Transport   Department for Work and Pensions   Department of Energy and Climate Change   Department of Health   Foreign and Commonwealth Office   HM Treasury   Home Office   Ministry of Defence   Ministry of Justice   Northern Ireland Office   Scotland Office   Wales Office   See all departments News Calendar Recent Comments  Sponsored Advert   Follow Us on Twitter Tweets by @gov_wire  Latest Government News Press release: Lords to consider landmark reforms to mental health care  Press release: PM pledges joint action to keep women and girls safe at night The latest updates on Storm Bert Guidance: River Thames: current river conditions Press release: New protections for whistleblowers under NHS manager proposals Transparency data: Small boat activity in the English Channel Book and manage theory tests for your pupils Press release: 1 million visits to Change.NHS.UK as roadshow hits Leicestershire Transparency data: Small boat activity in the English Channel Press release: Ten nation military partnership successfully completes major exercise in Latvia    Business Climate Crime Defence Economy Environment Housing Immigration NHS Overseas Schools Tax Transport Work ALL ❯ © 2024 Copyright CliqTo Media Ltd. Registered in England, company number 7575287. Privacy Policy | Terms & Conditions | Copyright Notice Contains public sector information licensed under the Open Government Licence v3.0. Share This Enjoyed this? Why not share it with others if you've found it useful by using one of the tools below: