ABSTRACT

A substantial and coordinated global effort is required to achieve net zero emissions by 2050. Deployment of large-scale clean energy processes that use best available technologies are required. Low-emission or blue hydrogen (H₂) is emerging as a key technology for decarbonising hard-to-abate emissions from heavy industry. A case study using a cradle-to-grave greenhouse gas (GHG) lifecycle assessment (LCA) enables the carbon intensity of H₂ production to be evaluated, focusing on the benefits of substituting low-emissions H₂ for natural gas (NG) as fuel gas at an example operational gas plant. The GHG LCA estimates the predicted carbon dioxide (CO₂) emissions associated with H₂ produced by autothermal reforming (ATR) technology combined with carbon capture and storage (CCS). This paper conducted a cradle-to-grave LCA using energy and mass allocation methods, which allowed for a comprehensive assessment of emissions across various stages, including extraction, processing, production and the substitution of NG with low-emissions H₂ for a typical plant’s electricity generation gas turbines. We examined how different design elements and assumptions can influence carbon intensity. Insights into the potential for ATR technology to achieve substantial CO₂ emission reductions in the energy industry are provided. The resulting carbon intensity of energy production from a gas turbine is 5.12 tCO₂-eq/TJ when using low-emissions H₂, substantially lower compared to 55.08 tCO₂-eq/TJ when using conventional natural gas as fuel. This emphasises the significant environmental benefits of this approach Furthermore, the paper identifies key emission sources and highlights opportunities for additional emissions reduction that can be adapted to different H₂ production processes.