Techno-economic and environmental life cycle analysis of renewable-based combined potassium - calcium looping cycle for direct air CO2 capture
Călin-Cristian Cormoş
Abstract
Reduction of greenhouse gas emissions is a critical important element for reaching global climate neutrality. This work evaluates an innovative energy- and cost-efficient potassium - calcium looping cycle as a promising Direct Air CO 2 Capture (DAC) technology. The potassium - calcium looping cycle is a reactive system which captures CO 2 by a combination of liquid solvent and solid sorbent. The high temperature energy recovery capability of this system makes it very promising for an energy- and cost-efficient CO 2 capture. To reduce the environmental impact, various renewable energy sources can be used to cover the required thermal duty, especially, the heat demand of the calcination reactor. The two investigated DAC concepts (fuelled by solar or biomass) are set to capture 1 Mt/y CO 2 from air with about 75 % capture rate. The conceptual design, detailed process modelling and validation, followed by overall energy optimization, done by thermal integration analysis, were used to assess the key techno-economic and environmental performance indicators. The renewable-based DAC systems have promising performance indicators in terms of high CO 2 capture efficiency, negative global warming potential (-981 / −995 kg CO 2 eq./t captured CO 2 ), lower environmental impact (quantified by Life Cycle Analysis - LCA), reduced energy penalty (5.1 GJ heat and 320 kWh power per ton of captured CO 2 ) and CO 2 capture costs (164–188 €/t). • Direct air CO 2 capture (DAC) by renewable-based potassium - calcium looping cycle. • Techno-economic and environmental (LCA) assessment of direct air CO 2 capture. • The concepts show 75 % capture rate, reduced energy penalty (5.1 GJ th and 320 kWh e /t CO 2 ). • The CO 2 capture costs of investigated DAC processes are promising (164–188 €/t). • The concepts have negative emissions (-981 / −995 kg/t CO 2 ) and lower environmental impact.