Adsorption Assisted Cryogenic Carbon Capture: an Alternate Path to Steam Driven Technologies to Decrease Cost and Carbon Footprint

Abstract

Carbon capture has gained momentum in addressing CO2 emissions where substitution of carbon feedstock by renewables is very challenging, such as in steel, refining, chemical, and cement industries. Gas streams containing 15% to 50% CO2 are low-hanging fruits for applying CO2 capture due to their prevalence in industry and lower capture cost linked to their high concentrations. Amine-based processes are historally considered as reference solutions for these applications, but they are no longer the only commercially viable solution today. Air Liquide has been working on a smart combination of its proprietary Adsorption and Cryogenic technologies, where Pressure Swing Adsorption (PSA) is used as a CO2 preconcentration and Cryogenic as CO2 purifiers: the Cryocap™ FG. This paper studies the influence of utilities (steam and electricity) on the carbon footprint and total cost of ownership of both amine and Cryocap™ FG technologies. The paper also studies Scope 1, 2, and 3 emissions and the TCO per ton of reduced CO2 for various footprint scenarios and typical utility costs. As it is a high efficiency power-driven technology, Cryocap™ FG resulted in a 90% reduction of Scope 1 emissions compared to 69-74% reduction with amine, depending on steam footprint, where limited waste heat is available for steam production. Cryocap™ FG was also found to be the most economical choice for electricity prices below 60€/MWh at any steam price, and the breakeven is at 120 €/MWh for a steam cost at around 10 €/t.