Intégration de procédés de captage direct du CO₂ dans l'air ambiant dans un système bas-carbone
Year: 2025
Type: dissertation
Abstract: This study provides a techno-economic assessment of various Direct Air Capture (DAC) technologies – absorption, adsorption, membrane-based, and hybrid systems – integrated with low-carbon and dispatchable energy sources. These separation techniques, mature and well known for point-of-source capture, are being studied for the DAC application envisaged to achieve carbon neutrality. It evaluates performance, energy needs, and pre-estimation of capture costs under realistic air conditions through sensitive analysis. The absorption process uses conventional amine solvent with heat pump enhancements like Lean Vapor Compression and Stripper Overhead Compression, reducing energy use by over 25%. However, capital costs offset these gains, keeping capture costs over 1000 €/tCO₂ for 0.1–1 MtCO₂/year. Reducing the limit on amine emissions can improve costs by up to 8%. Adsorption-based DAC using S-VTSA (steam assisted vacuum thermal swing adsorption) shows trade-offs between packed-bed and monolithic designs. While packed beds offer higher productivity, monoliths reduce energy use. At 100 ktCO₂/year, costs exceed 1500 €/tCO₂ for both designs, highlighting the need for better sorbents and process optimization. Gas permeation membrane-based DAC, though modular and solvent-free, suffers from low CO₂ purity and high energy demand, with costs over 5000 €/tCO₂, limiting its feasibility. A hybrid system combining adsorption and membrane separation improves CO₂ enrichment but remains energy-intensive, with costs above 1700 €/tCO₂. The adsorption step dominates both energy and cost contributions, highlighting it as a key area for future improvement. Integrating DAC with low-carbon power plant enables efficient thermal use and high carbon efficiency (>80%). A multi-criteria comparison highlights trade-off in energy, cost, emissions, water use, and technology readiness level.
Source: HAL
Author: Joannis, Paul De
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7154657439