Experimental determination of hydrate dissociation conditions in CO₂ + hexane + dodecane system, + 1-propanol or + tetra-n-butyl ammonium bromide

Hydrate dissociation conditions for one four-component system and two five-component systems, the CO₂ + hexane + dodecane + water system, the CO₂ + hexane + dodecane + 1-propanol + water system, and the CO₂ + hexane + dodecane + tetra-n-butyl ammonium bromide (TBAB) + water system, were measured in the pressure range of (1.5 to 4) MPa and temperature range of (283 to 290) K at (0.1, 0.2 and 0.3) mass fraction of 1-propanol or TBAB. The experimental measurements were performed using the isochoric pressure-search method in a high pressure blind cell. The hydrate dissociation conditions (temperature and pressure) for the CO₂ + hexane + dodecane + water system were compared with experimental data available in international literature were good agreement between the data was founded which indicates the viability of the experimental technique reported in this study. The experimental uncertainties were determined for temperature and pressure as combined standard uncertainties and are 0.16 K and 0.04 MPa, respectively. The relative standard uncertainty in composition was estimated to be 0.0014. In order to verify the reliability of the experimental data containing 1-propanol, a thermodynamic consistency test was performed.