Techno-economic assessment of waste heat-powered direct air capture in the refinery and petrochemical sectors in Saudi Arabia

Direct Air Capture (DAC) is increasingly recognized as a critical technology for achieving net-zero emissions, yet its large-scale deployment remains constrained by high energy and operational costs—particularly the need for reliable low-cost source of heat. This study presents a comprehensive technical and economic assessment of integrating DAC with low-grade industrial waste heat across Saudi Arabia’s refinery and petrochemical sectors. Using facility-level data, we estimate that approximately 84 TWh/year of waste heat is available—sufficient to support the capture of up to 42 MtCO₂ annually, offsetting around 34 % of current stationary emissions from these sectors. Our analysis shows that repurposing this underutilized thermal energy could reduce the average levelized cost of DAC (LCOD) for future commercial-scale systems to $148.5 per ton, significantly below current global DAC cost benchmarks. A marginal abatement cost curve reveals that the most cost-effective opportunities are concentrated in large, high-throughput industrial sites, emphasizing the importance of scale, centralized integration, and waste heat clustering. Further, our sensitivity analysis highlights the scale-up exponent, electricity price, and capital cost assumptions as the most influential factors driving cost outcomes. Overall, this study offers a scalable and actionable blueprint for DAC deployment in high-emitting industrial sectors and aligns closely with Saudi Arabia’s Circular Carbon Economy framework and 2060 net-zero target.