The condensation process of supercritical water gasification products in a bicubic supersonic nozzle.

This article focuses on the development and analysis of a supersonic nozzle-based condensation separation technology for supercritical water gasification products (SCWGP), primarily composed of hydrogen (H₂) and carbon dioxide (CO₂). The study establishes a flow and condensation model incorporating classical nucleation and droplet growth theories within a bicubic parametric supersonic nozzle, examining how inlet pressure, temperature, gas composition, and nitrogen (N₂) admixture affect condensation efficiency. Results indicate that higher inlet pressures and lower inlet temperatures enhance CO₂ condensation, with liquid CO₂ and droplets concentrating near the nozzle center, facilitating separation while minimizing wall erosion. Variations in CO₂ molar fraction significantly impact separation performance, whereas small amounts of N₂ have negligible effects, highlighting the importance of stable operating conditions for industrial application.