Hydrogen production, storage, utilisation and environmental impacts: a review

Ahmed I. Osman , Neha Mehta, Ahmed M. Elgarahy, Mahmoud Hefny, Amer Al-Hinai, Ala’a H. Al-Muhtaseb, David W. Rooney

Research output: Contribution to journalReview articlepeer-review

292 Citations (Scopus)
1366 Downloads (Pure)


Dihydrogen (H2), commonly named ‘hydrogen’, is increasingly recognised as a clean and reliable energy vector for decarbonisation and defossilisation by various sectors. The global hydrogen demand is projected to increase from 70 million tonnes in 2019 to 120 million tonnes by 2024. Hydrogen development should also meet the seventh goal of ‘affordable and clean energy’ of the United Nations. Here we review hydrogen production and life cycle analysis, hydrogen geological storage and hydrogen utilisation. Hydrogen is produced by water electrolysis, steam methane reforming, methane pyrolysis and coal gasification. We compare the environmental impact of hydrogen production routes by life cycle analysis. Hydrogen is used in power systems, transportation, hydrocarbon and ammonia production, and metallugical industries. Overall, combining electrolysis-generated hydrogen with hydrogen storage in underground porous media such as geological reservoirs and salt caverns is well suited for shifting excess off-peak energy to meet dispatchable on-peak demand.

Original languageEnglish
JournalEnvironmental Chemistry Letters
Early online date06 Oct 2021
Publication statusEarly online date - 06 Oct 2021

Bibliographical note

Funding Information:
The authors would like to thank OQ Oman for their generous financial support (project code: CR/DVC/SERC/19/01). The authors would also like to acknowledge the support of the Sustainable Energy Research Centre at Sultan Qaboos University. Ahmed Osman and David Rooney wish to acknowledge the support of The Bryden Centre project (Project ID VA5048). The Bryden Centre project is supported by the European Union’s INTERREG VA Programme, managed by the Special EU Programmes Body (SEUPB). Neha Mehta acknowledges funding from the Centre for Advanced Sustainable Energy (CASE). CASE is funded through Invest NI’s Competence Centre Programme and aims to transform the sustainable energy sector through business research.

Publisher Copyright:
© 2021, The Author(s).


  • Climate change
  • Hydrogen production
  • Hydrogen storage
  • Hydrogen utilisation
  • Life cycle assessment

ASJC Scopus subject areas

  • Environmental Chemistry


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