CO2 capture through gas hydrate formation in the presence of polyethyleneimine-surface-grafted clay

CO 2 capture through gas hydrate formation was performed using a stirring -type vessel in the presence of nanoclay and polyethyleneimine-grafted nanoclay. First, the grafting process was implemented via the wet impregnation method. The nanoparticles were characterized using FT-IR, FESEM, EDS, BET, XRD, TGA, Zeta potential, and DLS analyses. The characterization analyses confirmed surface -grafting of the nanoclay. Then, the hydrate formation experiments were implemented at three various nanoparticle loadings (200, 400, and 500 ppm). Water -to -hydrate conversion, CO 2 gas consumption, apparent rate constant, and hydrate storage capacity were obtained and compared. Prior to conducting the CO 2 hydrate formation experiments in the presence of nanoparticles, the rocking -type and stirring -type vessels were compared to evaluate the hydrate formation rate (using pure water). Stirring -type vessel exhibited higher hydrate formation rates than rocking -type vessel along with improved gas storage performance which resulted in a 22.4% increase in CO 2 consumption. Thus, the effect of additives was examined using the stirring -type vessel. Surface -grafted nanoclay led to higher CO 2 consumption compared to nanoclay at all concentrations. Using 500 ppm of modified nanoclay, grafted by 50 mass% polyethyleneimine (PEI) solution as additive, the maximum enhancement of CO 2 consumption in the hydrate phase in comparison with pure water was obtained, along with the greatest water to hydrate conversion value (39.67). This study introduces a new technique by modifying nanoclay with PEI to improve CO 2 storage in gas hydrate phase, presenting potential advancements in gas storage technology.