Further written evidence submitted by the Royal Society of Edinburgh (HCC0053)

Scottish Affairs Committee inquiry into hydrogen and carbon capture in Scotland – supplementary response by the Royal Society of Edinburgh

 

  1. The Royal Society of Edinburgh (RSE) was pleased to be invited to give oral evidence in support of the Scottish Affairs Committee’s (SAC) inquiry into hydrogen and carbon capture in Scotland on 18 July 2022, following on from its written submission to the inquiry in spring of 2022. The RSE was represented by Fellow and Professor Andy Sloan FRSE, Managing Director at COWI UK Limited.
  2. Professor Sloan was specifically asked by Ms Deirdre Brock MP to provide follow-up evidence in reference to a number of national and international projects mentioned during the session (see Q174 in the official transcript). The below initiatives were referenced as successful case studies and models that Scotland could look to emulate in the context of building a coupled demand/market and supply for green fuels. Professor Sloan would be pleased to elaborate further should Ms Brock and/or the SAC find this helpful.
  1. The RSE would also like to take this opportunity to offer some additional nuance to the debate about blue versus green hydrogen, which was brought up during the course of the session. The RSE’s position is that green hydrogen should continue to be prioritised as the more overtly sustainable option with blue hydrogen acting as a potential ‘bridge’. This is due to the fact that blue hydrogen is still predominantly derived from natural gas which is subject to cost fluctuations and supply shortages, particularly in the context of the ongoing war in Ukraine, and is ultimately unlikely to be a realistic option. However, it is important to note that blue hydrogen is technically any hydrogen that employs carbon capture and storage (CCS) in its technology pathway. In addition to using natural gas, it can also be produced via alternative routes such as biomass gasification. Subjecting biomass to high temperatures (>700°C) and a highly controlled supply of oxygen or steam creates synthetic gas (‘syngas’). This syngas can then be purified into hydrogen. With the appropriate carbon capture technologies, biomass gasification results in net carbon removal and can find a productive end for what would otherwise be waste materials, contributing to a circular economy. However, it is important to acknowledge that not all biomass feedstocks are inherently sustainable, particularly those that impinge upon agricultural production or biodiversity (for more information, please see our response to the Scottish Affairs Committee’s inquiry into renewable energy in Scotland).
  2. Emerging research by Heriot-Watt University, funded by Malaysian company PETRONAS, suggests that Scotland may have an abundance of specific feedstocks – such as waste arising from the whisky industry or marine algae – to fuel large-scale blue hydrogen production from biomass gasification and pyrolysis. Pursuing this opportunity could yield appreciable economic and environmental benefits for Scotland. A commitment to continued blue hydrogen production could also accelerate the maturation of associated carbon capture and storage technologies, given these are an integral part of the process. Professor Raffaella Ocone FRSE, Professor of Chemical Engineering at Heriot Watt University who chaired the RSE’s response to both the Committee’s current inquiry and Scottish Government’s Draft Hydrogen Action Plan, would be pleased to be contacted for more information on this research and on the potential role of blue hydrogen in Scotland’s future energy system.

 

August 2022