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A synthetic technique was used to measure the solubility of carbon dioxide in three aqueous solutions of 2,2′-methyliminodiethanol (N-methyldiethanolamine, MDEA) and piperazine (PZ) at around (313, 333, 353, and 393) K and pressures between about (0.2 and 10) MPa. The molalities of (MDEA + PZ) in the aqueous solutions were (2.2 + 1.97), (4.22 + 2.01), and (7.83 + 2.07), respectively. The loading of the amines by carbon dioxide (i.e., the molar ratio of (MDEA + PZ) and CO2varied between 0.2 and 2.0 The new experimental results are to supplement previously published experimental data of our research group for a single solution of both amines {molalities of (MDEA + PZ) in the aqueous solutions: (2.0 + 2.0)}. The new experimental results are compared to predictions from a model that combines previously published models for (CO2+ MDEA + H2O) and (CO2+ PZ + H2O). [ABSTRACT FROM AUTHOR]

Experimental results for the solubility of tetrafluoromethane (CF4, R14) in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (hmimTf2N) are presented for temperatures between 293.3 and 413.3 K, at pressures (gas molalities) up to 9.6 MPa (0.22 mol kg-1). The experimental results were determined with a high-pressure view-cell technique operating on the synthetic method. The experimental data were used to determine Henry's constant of tetrafluoromethane in hmimTf2N. The results for the Henry's constant (at zero pressure) are correlated (on the molality scale) within the experimental uncertainty (i.e., about 1.1%) by ln(%@mt;sys@%%@ital@%k%@rsf@%%@sx@%H,%@/hd@%CF%@sb@%4%@sbx@%%@be@%%@/hd@%%@fn;(;vis;full;auto@%0%@fnx;);vis;full@%%@/hd@%%@sxx@%%@mx@%/MPa) 7.537 − 893.8/(T/K) − 0.003977(T/K). Henry's law was also extended to describe the gas solubility at higher pressures. Furthermore, a cubic equation of state was used to correlate the gas solubility over the entire range of experimentally investigated temperature and pressure. Both methods proved suited for a reliable correlation of the new experimental data. [ABSTRACT FROM AUTHOR]