Molar Heat Capacities of Aqueous Binary Mixtures of 2-(tert-butylamino)ethanol and its Ternaries with Piperazine or Lithium Bromide

DOI: 10.5176/2301-3761_CCECP14.17

Authors: Rhedita Wanda Olivia, Meng-Hui Li, and Rhoda B. Leron

Abstract:

Sterically hindered amines are potential alternative absorbents to alkanolamines in CO2 capture. In the present work, we reported new experimental data on the molar heat capacities, CP, of aqueous mixtures of the sterically hindered amine 2-tert-butylamino-ethanol and its aqueous ternaries containing piperazine or lithium bromide. Measurements were done using a differential scanning calorimeter at temperatures from 303.15 K to 353.15 K and atmospheric pressure. The excess molar heat capacities, CPE, of the binary mixtures were determined, and the obtained data were correlated with temperature and composition using a RedlichKister-type equation. A modified Sohnel and Novotny equation was used to represent the CP of the ternary mixtures as function of temperature and amine concentration. Results showed that the applied models yield good representation of the experimental CP data as suggested by the average absolute deviation values between the experimental and the calculated data of 0.2{6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} and 0.1{6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} for the binary and ternary systems, respectively. Thus, they can used in process engineering to yield accurate predictions of the CP of the studied amine systems.

Keywords: 2-tert-butylamino-ethanol; molar heat capacity; excess molar heat capacity; RedlichKister equation; Sohnel and Novotny equation