Decarbonisation Technology - August 2023 Issue

green power generation resources and store the resulting energy in a fuel source rather than batteries. To this end, Becht has supported entities in the design and modification of their gas turbines to allow high hydrogen firing as a way to future-proof the economic and technical viability of those assets (see Figure 2 ). The largest projection of hydrogen usage growth is in the transportation sector, as hydrocarbon-based fuels account for more than 15% of total global greenhouse gas emissions. While the principle of a fuel cell is relatively straightforward as a means to convert hydrogen to energy and water, the practicality of using hydrogen for transportation energy faces several challenges. The current number of cars and trucks that use hydrogen as a fuel source is only around 40,000 out of ~1.5 billion vehicles globally in 2020. Several reasons exist for this low adoption rate. Firstly, the typical usage life of a car or truck ranges from 7-10 years and is expected to elongate in the near term due to post-COVID supply chain issues. Therefore, it will take many years to change the fleet to new fuel sources, as consumers and businesses will sparingly change their vehicles. Next, the hydrogen fuelling station infrastructure is still in its infancy, despite years of advocacy and policy changes by regulatory entities. Currently, only large urban areas with advantaged tax incentives and economies of scale can justify the refuelling infrastructure. Other challenges include distribution and logistics systems, as well as economics, which will be addressed in subsequent sections. That said, signification changes to each of these areas will be required to increase the speed of adoption, or the use of hydrogen for direct transportation fuels may suffer the fate of the UK hydrogen refuelling stations. The most promising options are the use of hydrogen for heavy trucking, buses, and large transport fleets that can operate within a centralised hydrogen hub system. Producers On the production side, several options and technologies are available to produce hydrogen. Over recent years, the 'colours of hydrogen' have been used to delineate the production

approaches (see Figure 1). Grey, brown, and blue hydrogen are commercially proven technologies that produce as much as 90% of the global hydrogen supply today. Over time, in order to meet decarbonisation requirements, grey hydrogen will decline to be replaced by both blue and green hydrogen. Most industry experts expect that blue hydrogen will lead the way initially to meet near-term decarbonised hydrogen production needs, given the economies of scale and high technology readiness, especially since the CO₂ removal technologies from both the process and combustion sides of a typical steam methane reformer (SMR) has been used for many years and the solvent technologies are continuing to evolve in efficiency and effectiveness. That said, many blue hydrogen projects are being impacted by the concern of investors about financing assets that could be ‘stranded’ by disadvantaged economics or emission regulation changes prior to the end of the typical equipment life. Therefore, investors are questioning if the project economics will remain for a typical 20-year project life if incentives or even regular limits shift that life to 5-10 years. Pink hydrogen, through the use of nuclear power, is a viable option. However, it is impacted by the stigma of nuclear power itself, the current costs to build nuclear facilities, and some regulators not ‘counting’ pink hydrogen as a source of decarbonised hydrogen. Though green hydrogen, through the use of electrolysis, has existed for many years, this technology is experiencing a renaissance of research and development to improve efficiency, alter the materials of construction, and allow for the use of lower purity water for production. While green hydrogen does result in a completely decarbonised source of hydrogen (with the clear assumption that only renewable power is used and when ignoring the carbon intensity of the equipment and site construction) as well as a source of high-purity oxygen, this technology does have challenges that need to be overcome. Firstly, the power requirements are substantial for existing technologies, thereby requiring around 55 kWh/kg H₂ produced. To put that in perspective, for a typical 50 MMSCFD hydrogen plant (most refinery

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