Process systems engineering: a key enabler of adsorption-based direct air capture

Direct air capture (DAC) is a promising technology for removing carbon dioxide from the atmosphere. However, its widespread deployment is challenged by high energy requirements, water management, sorbent degradation, integration with variable renewable energy sources, and fluctuating climatic conditions. The design, operation, and control of solid adsorption-DAC systems is a complex problem that requires holistic engineering of the adsorbent material, adsorption system, DAC process, and upstream and downstream operations. In this review, we show how Process Systems Engineering (PSE) can address this multiscale system design challenge by highlighting recent PSE advancements in three areas: (i) process-informed sorbent selection, (ii) heat integration and water management, and (iii) technological viability assessments. We summarize the progress that PSE has made in connecting sorbent properties to system design and optimization, outlining the key metrics and workflow needed to advance from sorbent to comprehensive system evaluation. We highlight effective energy and resource management strategies, such as DAC integration with heat and power generation, the use of renewable electricity or underutilized sources from existing infrastructure, and combined heat and water integration. For viability assessments, we emphasize comprehensive approaches that integrate technoeconomic and life cycle assessments with sorbent degradation, geospatial analysis, and scaling predictions. We conclude with future PSE directions that will be important for scaling adsorption-DAC, including process strategies for variable energy and climate conditions, predictive sorbent degradation models, and optimized scheduling to balance energy and capital. • PSE advances sorbent selection, heat/water integration, and viability assessment. • Process-informed sorbent selection balances performance, cost, and environmental impact. • Strategic resource integration reduces energy demand and improves carbon removal. • Assessments connect sorbents and processes to local and global impacts. • PSE can address DAC cost, variable climates, sorbent degradation, and scheduling.