SHANDONG SCIENCE ›› 2016, Vol. 29 ›› Issue (2): 49-56.doi: 10.3976/j.issn.1002-4026.2016.02.010

• Energy and Power • Previous Articles     Next Articles

Heat capacity and excess enthalpy of [bmim]Zn2Cl5/NH3 binary system solution

CHEN Wei1,LIANG Shiqiang2*,GUO Yongxian2   

  1. 1. School of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, China;
    2. Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2016-01-19 Online:2016-04-20 Published:2016-04-20

Abstract:

We measured thermogravimetric curve for ionic liquid [bmim]Zn2Cl5 at T= (323.15~1 173.15) K. Results show that [bmim]Zn2Cl5 has higher thermal stability at T < 637.15 K. We acquired heat capacity data of [bmim]Zn2Cl5 through DSC scan, which could be well fitted with a conic curve at T= (251.15~383.15) K. We measured mole excess enthalpy of binary system [bmim]Zn2Cl5 (2) + NH3 (1) for ammonia molar fractions x1 = (0.60 ~ 0.95) at T=288.15 K,303.15 K,318.15 K,333.15 K.We employed NRTL model to fit excess enthalpy data and acquired binary adjustable parameters and nonrandom parameters. Measurement error and maximum fitting deviation of excess enthalpy data are respectively less than 4.8% and 4.3%. Based on heat capacity of [bmim]Zn2Cl5 and excess enthalpy data of [bmim]Zn2Cl5/NH3, we also calculated the enthalpy of [bmim]Zn2Cl5/NH3 solution for ammonia mass fractions of w1 = (0 ~1) and temperature scope T=(273.15 ~ 343.15) K. The obtained enthalpyconcentration diagram is essential to the investigation of the thermodynamic performances of [bmim]Zn2Cl5/NH3 absorption refrigeration system.

Key words: ionic liquid, [bmim]Zn2Cl5/NH3, NRTL model, heat capacity, excess enthalpy

CLC Number: 

  • TB64