Thermodynamic behavior and spectroscopic properties of CO and C3H8 mixed gas hydrates: Implications for hydrate-based gas separation

Dissociation Kinetics and Metastability of Carbon Monoxide Hydrates Correlating with Phase Change in Water Ice

“…It was revealed that the binary gas hydrates of CH 4 and C 3 H 8 or butanes ( n -C 4 H 10 and iso-C 4 H 10 ) lose the self-preservation phenomenon as the amounts of C 3 H 8 and C 4 H 10 increase . These suggested that the coexistence of a particular type of a guest such as C 3 H 8 probably eliminated the self-preservation phenomenon of CO + C 3 H 8 hydrates . Accordingly, we concluded that the preservation performance of mixed-gas hydrates is a combination of the performances of each simple hydrate.…”

“…It is known that the dissociation process of various gas hydrates depends considerably on the guest species: 26 62 These suggested that the coexistence of a particular type of a guest such as C 3 H 8 probably eliminated the selfpreservation phenomenon of CO + C 3 H 8 hydrates. 22 Accordingly, we concluded that the preservation performance of mixed-gas hydrates is a combination of the performances of each simple hydrate. For instance, binary gas hydrates containing guests whose simple hydrates exhibit self-preservation constitute an index that suggests the presence of selfpreservation in mixed-gas hydrate systems.…”

“…Oppositely, a recent study on CO + propane (C 3 H 8 ) gas hydrates suggested that these binary gas hydrates dissociated completely up to ∼200 K in one step by temperature ramping. 22 Accordingly, these results suggested that binary gas hydrates of CO and CH 4 , CO 2 , N 2 , or Ar exhibited a preservation performance that was a combination of the performance of each simple hydrate. Notably, certain amounts of the CO + CH 4 and CO + CO 2 hydrates were preserved up to 273 K depending on the mixed composition of CO, while CO + N 2 and CO + Ar hydrates completely dissociated at ∼240 K, similar to the simple CO hydrate.…”

“…A similar trend in the PXRD pattern, showing the occurrence and transformation of ice Isd, was observed for the simple and binary CO hydrates. Oppositely, a recent study on CO + propane (C 3 H 8 ) gas hydrates suggested that these binary gas hydrates dissociated completely up to ∼200 K in one step by temperature ramping . Accordingly, these results suggested that binary gas hydrates of CO and CH 4 , CO 2 , N 2 , or Ar exhibited a preservation performance that was a combination of the performance of each simple hydrate.…”

“…In addition, CO is an industrially important substance, along with CH 4 and CO 2 from the viewpoint of C1 (single carbon molecule) chemistry. CO is produced by the incomplete combustion of natural gas, and studies on CO and CO binary gas hydrates are required for their practical applications in gas storage and separation by gas hydrates. − …”