Experimental Investigation and Kinetic Model of CO2 + C3H8 Hydrate Formation in Porous Media for Seawater Desalination

Abstract

This study seeks to propel the efficacy and predictive accuracy of kinetic models in hydrate-based desalination, a field in which the rate of hydrate formation is a critical determinant of its industrial feasibility and optimization. This study investigates the impact of introducing varying media, quartz sand, nanocopper, and graphite, into the formation of CO₂ + C₃H₈ hydrates in salt solutions. The findings indicate that medium-sized quartz sand can adversely affect gas uptake, with the degree of impact being contingent on the particle size and filling height. Contrarily, the incorporation of nanocopper and graphite notably expedites hydrate formation. Notably, the reaction rate does not exhibit a simple inverse relationship with the particle size; instead, an optimized median size provides the best outcomes. In particular, using copper nanoparticles ranging from 10 to 30 nm and graphite particles around 6.5 μm, both at a concentration of 0.10 wt %, yielded significant increases of 25.89 and 26.53% in the resulting water-to-hydrate conversion to 32.77 and 32.94%, respectively, at the beginning of 1 h compared to a baseline saltwater solution. This study also introduces a sophisticated kinetic model grounded in experimental data designed to predict the rates of hydrate formation in seawater and porous media with greater precision. The model integrates the dynamics among the chemical potential difference, intrinsic formation rate, and heat and mass transfer limitations. Validation under various conditions confirms the model’s robustness and utility, substantially advancing the ability to refine and anticipate hydrate-based desalination process performance.