Techno-economic feasibility assessment of temperature vacuum swing adsorption using metal–organic frameworks for direct air capture in the UAE

Abstract

Direct air capture (DAC) has emerged as a critical negative-emissions technology for meeting national and global decarbonisation targets. However, its feasibility under region-specific climatic and economic conditions remains insufficiently explored, particularly in the Gulf region. This study presents a comprehensive techno-economic assessment of a Temperature–Vacuum Swing Adsorption (TVSA) system employing MIL-101(Cr)–PEI-800-coated monolithic structures for DAC in the United Arab Emirates (UAE). The analysis integrates equilibrium-based process simulation, energy modelling, bottom-up cost estimation, and sensitivity and scenario analyses to evaluate system performance under representative UAE conditions. Results indicate a CO2 working capacity of 0.87 mmol/g and a capture efficiency of 94.46%, yielding 31.1 kg/day of CO2 removal for a single monolith. A dedicated quantitative analysis of water co-adsorption under UAE operating conditions reveals that water co-desorption, rather than CO2 desorption, accounts for the dominant thermal load, contributing 72.53% to the total specific energy demand of 63.21 GJ/tCO2. The baseline levelised cost of direct air capture (LCOD) for the pilot-scale, diesel-powered configuration is estimated at USD 4817.61/tCO2, ruling out its economic feasibility at this scale and level of energy dependency. A sensitivity analysis across six parameters identifies economies of scale, diesel fuel price, and waste heat integration as the dominant LCOD drivers. Scenario analysis shows that combining large-scale deployment with full waste-heat substitution and solar electricity yields a best-case LCOD of USD 40.47/tCO2, surpassing the aspirational DAC target of USD 100/tCO2.These findings provide a replicable, quantitative framework for region-specific DAC feasibility assessment and offer actionable guidance for research prioritisation, investment planning, and policy design for DAC deployment in the UAE and the broader Gulf regions.

keywords: Direct air capture, Metal–organic frameworks, Net-zero, Temperature vacuum swing adsorption, UAE