Regulations, Codes & Standards (RCS)

In response to the UK Government’s commitment to achieve net-zero carbon emissions by 2050 a range of research and demonstration projects are underway to investigate the feasibility of using hydrogen in place of natural gas within the national transmission and distribution system. In order for these projects to achieve their full scope of work a mechanism for performing hazardous area classification for hydrogen installations is required. At present IGEM/SR/25 is used to undertake such assessments for natural gas installations but the standard is not currently applicable to hydrogen or hydrogen/natural gas blends.<br/>This report presents updated data and a summary of the recommended methodologies for hazardous area classification of installations using hydrogen or blends of up to 20% hydrogen in natural gas. The contents of this report are intended to provide a technical commentary and the data for a hydrogen-specific supplement to IGEM/SR/25. The supplement will specifically cover 100% hydrogen and a 20/80% by volume blend of hydrogen/natural gas. Reference to intermediate blends is included in this report where appropriate to cover the anticipated step-wise introduction of hydrogen into the natural gas network.<br/>This report is divided into a series of appendices each of which covers a specific area of the IGEM standard. Each appendix includes a summary of specific recommendations made to enable IGEM/SR/25 to be applied to hydrogen and blends of up to 20% hydrogen in natural gas. The reader is encouraged to review the individual appendices for specific conclusions associated with the topic areas addressed in this report.<br/>In general the existing methodologies and approaches used for area classification in IGEM/SR/25 have been deemed appropriate for installations using either hydrogen or blends of up to 20% hydrogen in natural gas. Where necessary revised versions of the equations and zoning distances used in the standard are presented which account for the influence of material property differences between natural gas and the two alternative fuels considered in this work.

Hydrogen fuelled vehicles can play a key role in the decarbonisation of transport and reducing emissions. To ensure the durability of fuel cells a specification has been developed (ISO 14687) setting upper limits to the amount fraction of a series of impurities. Demonstrating conformity with this standard requires demonstrating by measurement that the actual levels of the impurities are below the thresholds. Currently the industry is unable to do so for measurement standards and sensitive dedicated analytical methods are lacking. In this work we report on the development of such measurement standards and methods for four reactive components: formaldehyde formic acid hydrogen chloride and hydrogen fluoride. The primary measurement standard is based on permeation and the analytical methods on highly sensitive and selective laser-based spectroscopic techniques. Relative expanded uncertainties at the ISO 14687 threshold level in hydrogen of 4% (formaldehyde) 8% (formic acid) 5% (hydrogen chloride) and 8% (hydrogen fluoride) have been achieved.

In this paper we review our recent results in developing gas sensors for hydrogen using various device structures including ZnO nanowires and GaN High Electron Mobility Transistors (HEMTs). ZnO nanowires are particularly interesting because they have a large surface area to volume ratio which will improve sensitivity and because they operate at low current levels will have low power requirements in a sensor module. GaN-based devices offer the advantage of the HEMT structure high temperature operation and simple integration with existing fabrication technology and sensing systems. Improvements in sensitivity recoverability and reliability are presented. Also reported are demonstrations of detection of other gases including CO2 and C2H4 using functionalized GaN HEMTs. This is critical for the development of lab-on-a-chip type systems and can provide a significant advance towards a market-ready sensor application.

This Supplement gives additional requirements and qualifications for the transmission of Hydrogen including Natural Gas/Hydrogen blended mixtures (subsequently referred to as NG/H blends) and for the repurposing of Natural Gas (NG) pipelines to Hydrogen service. For the purposes of this document any NG/H blend above 10% MOL is considered to be an equivalence to 100% hydrogen. For blends below 10% MOL there is no evidence to confirm that blends containing up to 10 mol.% hydrogen do not cause material degradation but it is considered that the risk is low.

This Supplement covers the design construction inspection testing operation and maintenance of steel pipelines and certain associated installations in Hydrogen service and the repurposing of NG pipelines to Hydrogen service at maximum operating pressure (MOP) exceeding 7 bar and not exceeding 137.9 bar.

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A range of existing and newly developed hydrogen standards certification and labelling (SCL) schemes aim to promote the role of ‘renewable’ ‘clean’ or ‘green’ hydrogen in decarbonising energy transitions. This paper analyses a sample of these SCLs to assess their role in the scaling up of renewable hydrogen and its derivatives. To analyse these hydrogen SCLs we embellish a novel conceptual framework that brings together Sustainability Systems Thinking and Governance (SSG) literatures. The results reveal noteworthy scheme differences in motivation approach criteria and governance; highlighting the complex interconnected and dynamic reality within which energy systems are embedded. We consider whether the sustainable utilisation of renewable hydrogen is well-served by the proliferation of SCLs and recommend an SSG-informed approach. An SSG approach will better promote collaboration towards an authoritative global multistakeholder compromise on hydrogen certification that balances economic considerations with social and environmental dimensions.