| Popis: |
A thermodynamic model in Aspen Plus ® was developed to predict properties of piperazine (PZ)/H 2 O and PZ/H 2 O/CO 2 . A sequential regression was performed to represent recently acquired loaded and unloaded heat capacity, CO 2 solubility, CO 2 activity coefficient, speciation, and unloaded and loaded amine volatility data. The resulting model is able to predict each of these properties over operationally significant loading and temperature ranges (0.20−0.40 mol CO 2 /mol alkalinity and 40 °C−160 °C). The predicted heat of absorption for 8 m PZ solution at 0.35 mol CO 2 /mol alkalinity between 40 °C and 160 °C was 65±4 kJ/mol CO 2 . The temperature dependence of the heat of absorption was predicted using three analytical methods, each of which predicted different trends but similar ranges between 40 °C and 160 °C. The sequential regression methodology has also been applied to methyl-diethanolamine (MDEA) and MDEA/PZ. Ultimately this thermodynamic model will be modified in Aspen Plus ® to predict kinetic and transport data as well, and the resulting model will be used to design and optimize a post-combustion absorption/stripping process. |
