Decarb

The project

The use of natural gas as a primary energy source represents a major issue to global warming.

Decarbonisation of the gas grids is a possible solution, alongside electrification, to meet the climate change targets and reduce carbon dioxide emissions. This project will be the first large scale project of its kind that will tackle four measurement challenges that the gas industry need to solve before they can decarbonise the gas grid through introduction of biomethane, hydrogen-enriched natural gas, 100 % hydrogen, and carbon capture and storage (CCS). The project will cover the priority challenges within flow metering, gas composition, physical properties and safety (including monitoring of gas leaks).

The European Union set a target to reduce carbon emissions by 55 % by 2030 and become carbon neutral by 2050. To support meeting these ambitious targets the Green Deal was introduced by the European Commission, which included several aims that align with this project, including increased use of biomethane and hydrogen to reduce natural gas, and use of carbon capture and storage to reduce emissions from hydrogen and power production.

Early efforts were made to understand current measurement challenges of the energy gas industry through contacting stakeholders directly, running an online survey hosted by EURAMET Task Group on “Metrology for Energy” in 2018 (40 stakeholder entries) and via a workshop hosted by EMN Energy Gases. The common topic that was raised involved activities required for decarbonisation of the gas grid. and the following specific priority challenges were identified by stakeholders:

• It is currently not possible to calculate flow of alternative energy gases in the gas grid such as hydrogen and hydrogen-enriched natural gas for determining costs when charging customers with required accuracies.
• Gas composition measurements are required in the gas grid to determine energy content (for costing) and quality purposes to avoid, for example, degradation of appliances. Currently there is a lack of traceable gas analysis methods for biomethane and 100 % hydrogen, and also no validated method for rapid measurement of hydrogen in natural gas to ensure blending is within tolerance limits or compositional analysis of carbon dioxide in CCS for metering and purity.
• Physical property measurements in the gas grid are important for designing efficient decarbonised gas grids and CCS sites, and for accurate flow metering. Currently there is a lack of experimental results necessary to validate numerical methods adopted by industries for predicting the properties of the alternative gases highlighted above.
• Decarbonising the gas grid requires some modification of safety measures such as leak detection (where portable monitors should be able to distinguish between a hydrogen and natural gas leak). Currently it is not possible to detect leaks of carbon dioxide above storage sites.

The specific objectives of the project are:

1. Flow metering – To develop metrology infrastructure to support new flow metering requirements, including development of new traceable facilities to enable calibration of flow meters for hydrogen and hydrogenenriched natural gas in the gas grid in accordance with the Directive 2014/32/EU Measuring Instruments (MID) with maximum permissible errors as low as ± 1 % depending on the type of flow meter, and metering of carbon dioxide in Carbon Capture and Storage (CCS) processes in accordance with the Emissions Trading System (EU ETS) with an accuracy of ± 1.5 – 2.5 %.
2. Gas composition – To develop new primary reference materials and gas analysis methods to support the gas industry in performing gas quality measurements for pure hydrogen gas (ISO 14687 Grade A), biomethane (EN 16723-1) and hydrogen-enriched natural gas (EN 16726) for domestic use (e.g. boilers and cookers), and purity analysis of carbon dioxide for carbon capture and storage processes to meet the recommendations of ISO/TR 27921. Gravimetric uncertainties for amount fraction levels in the primary reference materials will be appropriate for the relevant documentary standard but always lower than 20 % relative. Additionally, to organise a proficiency test and comparison to support the gas industry in developing and validating traceable commercial on-line gas analysis instruments capable of quickly monitoring hydrogen amount fraction in natural gas to accurately control blending within target tolerances.
3. Physical properties – To develop metrology infrastructure to support measurement of physical properties for hydrogen-enriched natural gas, including development and traceable validation of analytical instruments that perform measurements of calorific values, density and Wobbe index as specified in ISO 6976, ISO 12213 and ISO 20765. Multiphase properties of mixtures composed of high levels of impurities in carbon dioxide will also be validated.
4. Leak detection – To develop metrology infrastructure to support new leak detection requirements for decarbonising the gas grid. This includes traceable monitoring methods for accurately quantifying leaks of hydrogen or hydrogen-enriched natural gas from pipelines at 25 % of the lower explosive limit (for health and safety reasons), and carbon dioxide leaks from pipelines or underground storage in CCS processes to meet the requirements of EU ETS (accuracy of ± 1.5 – 2.5 %). To support the future role of mobile platforms by ensuring they are capable of accurate measurement of leaks.
5. Impact – To disseminate and facilitate the take up of the technology and measurement infrastructure developed in the project by the measurement supply chain (accredited laboratories, instrument manufacturers), standards developing organisations (ISO/CEN/CENELEC) and end users (hydrogen industry, gas network operators and suppliers).