CO 2 solubility measurement and thermodynamic modeling for 1-methylpiperazine/water/CO 2
- Citation data:
Fluid Phase Equilibria, ISSN: 0378-3812, Vol: 394, Page: 118-128
- Publication Year:
- Chemical Engineering; Chemistry; Physics and Astronomy
An accurate thermodynamic model is the primary element needed for the process simulation and optimization for CO 2 absorption in aqueous amine solutions. In this work, the thermodynamic model was built in Aspen Plus, using the electrolyte nonrandom two-liquid (ENRTL) activity coefficient model to represent vapor pressure and heat capacity data, simultaneously, for amine, vapor–liquid equilibrium (VLE), excess enthalpy ( H E ), and pKa data for amine/H 2 O, and CO 2 solubility data for amine/CO 2 /H 2 O. The cyclic diamine 1-methylpiperazine (1MPZ) is a promising amine for CO 2 capture. CO 2 solubility was measured for 1MPZ aqueous solutions at three concentrations – 10 wt%, 30 wt%, and 40 wt% and four temperatures – 313.15 K, 343.15 K, 373.15 K, and 393.15 K. The excess enthalpy for 1MPZ + H 2 O was obtained by the Setaram C80 calorimeter at 303.15 K and 323.15 K, within a whole mole-fraction range. The interaction parameters of nonrandom two-liquid model (NRTL) and ENRTL, along with the standard state properties of amine ions – protonated 1MPZ (1MPZH +, 1MPZH 2+ ), 1MPZ carbamate (1MPZCOO − ), and protonated 1MPZ carbamate (H1MPZCOO) – were regressed from data obtained from this work as well as literature, which agreed with the model calculation.