CO₂-assisted dehydrogenation-hydroformylation cascade enables syngas self-sufficiency and carbon-efficient propane upgrading.

Abstract

Propane upgrading is fundamentally constrained by the high energy demand of conventional dehydrogenation and the reliance of hydroformylation on fossil-derived syngas, limiting both efficiency and sustainability. We redesign this architecture by establishing a carbon dioxide (CO₂)-assisted oxidative dehydrogenation-hydroformylation (CO₂-ODH-HF) cascade that replaces propane dehydrogenation (PDH) with a CO₂-ODH reactor and circulates CO₂ to generate carbon monoxide (CO) and dihydrogen (H₂) internally. Aspen Plus simulations show that this shift in reaction route creates a syngas self-sufficient system in which propylene formation, CO₂ utilization, and hydroformylation become directly coupled. The integrated cascade enhances carbon-utilization efficiency, eliminates external CO procurement, and substantially reduces total production costs compared with PDH-HF. Life-cycle assessment further indicates ~42% lower greenhouse-gas emissions per kilogram of aldehyde produced, without triggering economic-environmental trade-offs. Sensitivity analyses reveal strong robustness against fluctuations in the feed price of liquefied petroleum gas (LPG) containing propane compounds, CO cost, and hydroformylation catalyst loss. By restructuring underlying reaction pathways and carbon flows, the CO₂-ODH-HF cascade establishes a scalable and carbon-efficient route for propane upgrading and aldehyde synthesis.