Hybrid technologies reduce cost of carbon capture from industry
Global warming resulting from the emission of greenhouse gases (GHGs) by power stations, industry and other sources is a major challenge Europe and the rest of the world face. Carbon capture utilisation and storage (CCUS) technologies could reduce carbon emissions by 90 % to 95 % from power generated by fossil fuels and energy-intensive industrial processes like the production of cement, ceramics, steel and petrochemicals. Such CO2 capture processes represent around 70 % of the total cost of the CCUS process. Highly intensive energy processes currently capture CO2 by bubbling it through water containing organic amines that bind to the gas. However, this process is inefficient compared to membrane separation and vacuum pressure swing adsorption based on solid sorbents. Unfortunately, deploying a stand-alone carbon capture system based only on membrane technology or only on solid sorbents is expensive because high CO2 recovery and purity targets significantly increase the energy expenses, as well as capital expenditure and operational expenditure compared to traditional amines scrubbing. Nonetheless, these disadvantages can be overcome by combining membrane technology with solid adsorbers in hybrid configurations.
A combined approach to CO2 capture: the best of both worlds
The EU-funded CARMOF project developed an effective hybrid post-combustion CO2 capture process based on 3D-printed structured adsorbents. “CARMOF is a hybrid process that combines the best aspects from membrane and solid sorbent technologies,” says project coordinator Costantino Martinez Cocera. CARMOF’s goal was to create high-performance dry adsorbers for post-combustion CO2 capture. The structures were based on 3D printing technologies containing a combination of metal organic frameworks, reduced graphene oxide or carbon nanotubules supported by polyethyleneimine binders and adsorbers. The structure was designed for the specific combination of gases from the selected industry. Researchers therefore produced functional absorbents at industrial facilities that combined advanced properties like electrical conductivity, CO2 sorption, high surface area, tuneable porosity and tuneable functionalisation of the core material.
Hybrid processes prove cheaper and better
“Integration of the different technologies is superior to a standalone process and avoids their disadvantages. Hybrid processes have shown their superiority not only for CO2 recovery, but also in the lower installation investment required,” observes Martinez Cocera. Adsorbents are shaped by 3D printing using the micro-extrusion of a highly viscous paste into structured porous materials. The microporous designs of the structures can be optimised to enable low pressure and fast kinetics of the carbon capture process. The technology is deployed and tested under real world conditions in cement works located in Greece. “The results will provide valuable information about how we can best utilise current technologies and exploit their combined impacts to provide major benefits for all industries with large carbon emissions, and for society as a whole,” Martinez Cocera concludes.
Keywords
CARMOF, carbon capture, CCSU, CO2, greenhouse gases, emissions, membrane, adsorbents, 3D printing, hybrid processes