An integrated solution to mitigate climate change through direct air capture and diabatic compressed air energy storage

Abstract

Direct air capture (DAC) is a technology designed to capture CO₂ directly from ambient air for carbon removal, while compressed air energy storage (CAES) involves compressing and storing air for later use in energy generation. However, diabatic CAES (D-CAES) systems, despite their commercial deployment, face limitations due to reliance on combustion, contributing to environmental pollution. Liquid-based DAC (L-DAC) systems offer negative emissions but are energy-intensive, often depending on electricity from natural gas plants. This study introduces an integrated system where L-DAC captures CO₂ emitted by D-CAES during discharge, using electricity directly supplied by D-CAES, thus addressing energy and environmental concerns. Implemented in Aspen Plus® V11 and validated with literature data, the system’s performance was assessed under various parameters. Results show a D-CAES round-trip efficiency of 59.27% and a levelized cost of electricity of $0.53/kWh. The cost of captured CO₂ from the air is $259/tCO₂. This study provides a comprehensive analysis and offers guidance for the sustainable commercial deployment of D-CAES while fostering advancements in DAC and energy storage integration.