Carbon Capture Porous Liquids in Blue Hydrogen Production - Reducing Energy and Cost

Reducing the energy requirement and carbon emissions of industrial-scale chemical separation processes is a key goal in slowing climate change. At present, these processes account for approximately 16% of all energy use in the US alone and produce significant greenhouse gas emissions.

International policies are transitioning towards a greener, hydrogen-based future where energy is created and consumed carbon neutrally. Green Hydrogen energy, produced through the electrolysis of water, is the future but is not expected to fulfil global hydrogen demand before 2060. While this technology develops, alternative solutions are required to augment hydrogen supplies, one of which is known as Blue Hydrogen.

Blue Hydrogen relies on reacting steam with methane from natural gas to form hydrogen with carbon dioxide (CO2) produced as a by-product. CO2 is captured through a chemical reaction and transferred, for use as a chemical feedstock or for storage in an underground reservoir, providing the Blue Hydrogen as a clean product. Current carbon capture methods rely on forming a chemical bond, which requires a significant energy cost to break, and results in high process costs and emissions.

Porous liquids (PLs) are unique chemical materials that are essentially molecular-sized cages entrained in a liquid carrier. These cages are large enough to allow gas molecules - CO2, for example - to enter their pores but too small to allow the liquid to pass into the cages and stop their function. These cages interact with their target molecule through a non-bonding chemical process called physisorption, meaning the energy required to regenerate the PLs and release CO2 is significantly less than current technologies.

Additionally, unlike existing carbon capture chemistry, PLs have long-term chemical stability and do not corrode infrastructure.

We have previously demonstrated the use of PLs in carbon capture for biogas to biomethane applications and believe this work can streamline a project focused on using PLs on Blue Hydrogen systems. This substitution will not only improve the carbon capture properties of the process but will also reduce the energy requirements in regenerating the carbon capture chemical, leading to system improvements and a significantly less polluting form of Blue Hydrogen.

Porous liquids have applications across a broad cross-section of industrial-scale chemical separations and are adaptable to specific chemical targets. This project will provide a firm foundation for expanding our carbon capture portfolio, providing the proof-of-concept validation needed for future funding.