The estimation of fugitive gas emissions from hydrogen production by natural gas steam reforming Yousef A. Alhamdani a , Mimi H. Hassim a,* , Rex T.L. Ng b , Markku Hurme c a Department of Chemical Engineering/Institute of Hydrogen Economy, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia b Department of Chemical and Biological Engineering, University of WisconsineMadison, Madison, WI, 53706, USA c Department of Biotechnology and Chemical Technology, Aalto University, P.O. Box 16100, FIN-00076, Aalto, Finland article info Article history: Received 6 October 2015 Accepted 11 July 2016 Available online xxx Keywords: Fugitive emissions Natural gas reforming Greenhouse gases emissions Occupational health effects abstract In recent years, a significant amount of interest has been directed towards using hydrogen as an alternative source of energy to fossil fuel. Even though hydrogen is emission free in its end use; the production of hydrogen itself requires energy and may cause process emissions including fugitive emissions from various sources, mainly the piping equipment and fittings. The emissions, even though not as large as stack emissions, they may still pose risks to the environment and health especially to the workers within the plant area. This paper presents the estimation of fugitive emissions from hydrogen production pro- cess via natural gas steam reforming. Firstly, the natural gas steam reforming process was simulated before the fugitive emissions of carbon monoxide (CO) and greenhouse gases (GHGs), such as methane (CH 4 ) and carbon dioxide (CO 2 ) in the process were estimated. Then, the consequent global warming potential (GWP) and the associated health risks due to the emissions were evaluated. A comparison of the GHG fugitive emissions with other sources of GHG emissions over the hydrogen production life cycle was also performed. Methane (CH 4 ) recorded the highest rate of fugitive emissions contributing to the greatest GWP. On the other hand, CO 2 represented the total stack emissions contributing to 100% of the total GWP. The concentrations of the gases emitted as fugitive emissions (CH 4 , CO 2 and CO) in the process area are below the threshold exposure limit indicating that the plant environment is safe for workers daily exposures to the emitted gases. © 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction Hydrogen is a vital energy carrier [1] which can serve as an energy source for domestic and commercial applications by supplying electricity and heating [2]. For instance, it can be used in various appliances such as hydrogen fuel cells [1], hydrogen fuel cell vehicles [2] and internal combustion en- gines vehicles [3]. Hydrogen can be produced from either renewable sources or fossil fuels [1,3,4]. However at the * Corresponding author. Fax: þ60 7 553 6165. E-mail address: mimi@cheme.utm.my (M.H. Hassim). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2016) 1 e10 http://dx.doi.org/10.1016/j.ijhydene.2016.07.274 0360-3199/© 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Alhamdani YA, et al., The estimation of fugitive gas emissions from hydrogen production by natural gas steam reforming, International Journal of Hydrogen Energy (2016), http://dx.doi.org/10.1016/j.ijhydene.2016.07.274