As the world grapples with climate change and natural resource limitations, governments, companies, and communities are heavily investing in the evaluation of various renewable energy solutions [1]. While solar and wind often receive the most attention, these energy sources are limited by variations in peak generation capacity, and they struggle to meet widely fluctuating user demand. Natural gas, hydrogen and ammonia provide pathways to address these challenges [2].
This new energy ecosystem creates new challenges in monitoring and controlling quality and safety throughout its production, storage, and delivery. Raman spectroscopy is a vibrational spectroscopy technique that is widely used industrially for process control and monitoring. Raman's ability to provide highly specific chemical information without extraction enables direct measurement in solids, liquids, or gases. New technology developments enable direct measurement in cryogenic liquids such as liquid natural gas. Raman spectroscopy is well-suited for gaseous measurements of these new energy carriers since it can measure homonuclear diatomic molecules including hydrogen, oxygen, and nitrogen, without extraction or conditioning.
This work shows real-world examples highlighting how Raman spectroscopy can cover applications that would otherwise require a whole suit of extractive analyzer technologies. One application demonstrates the control of blending natural gas with hydrogen. For this purpose, a Raman Rxn5 analyzer coupled with a Rxn-30 probe was used for the gas-phase measurement enabling tighter control of the hydrogen blending process with the potential to feed the sample gas stream back into the process stream. The same analyzer probe combination was used in the feed control of an ammonia process demonstrating high selectivity which enables tight control of the feed stream. As an example, for an in-situ liquid natural gas application a combination of a Rxn4 analyzer with a Rxn-41 applied to liquid natural gas loading / unloading processes is presented. Compared to classical gas chromatograph / vaporizer combinations the Raman analyzer can measure directly with the start of the process with much higher time resolution. This is very important for these kinds of short intermittent processes.
Literature:
[1] International Energy Agency, “World Energy Investment|, www.iea.org, 2023.
[2] The Royal Society, “The role of hydrogen and ammonia in meeting the net zero challenge”, Climate Change: Science and Solutions, 2021
