Introduction

Hydrogen is set to become a crucial part of the UK's future energy matrix as the Government strives to meet challenging targets for reducing greenhouse emissions. One application of hydrogen is to power fuel cell vehicles - these vehicles are emission-free at the point of use, and fossil fuel usage is eliminated if the hydrogen is generated from renewable energy sources.

Accurate analysis of the purity of the hydrogen used in fuel cells vehicles is required because even trace levels of some species may cause a severe loss of fuel cell performance.

Traceable measurement of the hydrogen storage capability of materials being developed by research groups around the world is essential to provide comparability of the claimed storage capabilities.

Hydrogen purity analysis

NPL is developing a suite of analytical methods to perform the accurate and traceable analysis of a wide range of impurities in hydrogen. The work is targeting the species and challenging limits of detections specified in the draft International Standard ISO/DIS 14687-2 (Product specification - Part 2: Proton exchange membrane (PEM) fuel cells for road vehicles).

The latest version of the draft standard (January 2011) specifies the analysis of the following species to the stated limits of detection:

●  Water ●  Total hydrocarbons ●  Oxygen ●  Helium ●  Nitrogen ●  Argon ●  Carbon dioxide ●  Carbon monoxide ●  Total sulphur compounds ●  Formaldehyde ●  Formic acid ●  Ammonia ●  Total halogenated compounds ●  Maximum particulate conc.

5 μmol/mol (ppm) 2 μmol/mol 5 μmol/mol 300 μmol/mol 100 μmol/mol 100 μmol/mol 2 μmol/mol 0.1 μmol/mol 0.004 μmol/mol 0.01 μmol/mol 0.2 μmol/mol 0.1 μmol/mol 0.05 μmol/mol 1 mg/kg

A summary of the analytical methods developed at NPL as of August 2011 is available here. Full details of the work are available in NPL report AS 64

Download a copy of NPL's Hydrogen Purity Analysis flyer

Hydrogen purity – collaborative research

NPL is participating in the following collaborative research projects:

• HyQ (Hydrogen fuel quality requirements for transportation and other energy applications): A JTI New Energy World project with 15 European partners.
• H2FC (Integrating European infrastructure to support science and development of hydrogen and fuel cell technologies): A EU Framework 7 project with 19 European partners.

Hydrogen storage

NPL is also carrying out research into:

• The synthesis and characterisation of novel nano-structured materials for the high-volume storage of hydrogen, e.g. work on carbon nanoscrolls has been published in Chemical Physics Letters, 465, 2008, 254-257.
• Measurements of the hydrogen storage capacity of novel storage materials.
• Investigation of the effects of the introduction of impurities in hydrogen on fuel cell output and performance.

Contact us

For further information on this research, or to request the purity analysis of a sample of hydrogen, please contact us:

Customer enquiry tel: +44 20 8943 6372
E-mail: gases@npl.co.uk