Selection of State Equation and Innovative Process Design for Removing CO2 by Azeotropic Distillation. Issue 4 (25th February 2021)

• Record Type: Journal Article
• Authors: Wang, Haiqin; Wang, Ce; Zhang, Zubin; Fan, Minglong; Yan, Xiaodong; Li, Fengqi
• Is Part Of: Chemical engineering & technology. Volume 44:Issue 4(2021)
• Page Start: 710
• Page End: 722
• Publication Date: 2021-02-25
• Subjects: Azeotropic distillation -- CO2 removal -- Equations of state -- Phase equilibria; Chemical engineering -- Periodicals; Chemical processes -- Periodicals; 660.05
• DOI: 10.1002/ceat.202000409
• Languages: English
• ISSNs: 0930-7516

Abstract

Abstract: A thermodynamic consistency test was performed on the gas‐liquid equilibrium data of three binary mixtures, namely, CH4 ‐C2 H6, CH4 ‐CO2, and C2 H6 ‐CO2, measured by Wei and Brown at three different temperatures to verify the reliability of the data. Peng‐Robinson (PR), Redlich‐Kwong (RK), and Soave‐Redlich‐Kwong (SRK) equations of state combined with Margles mixing rules were used to fit the gas‐liquid equilibrium data of these three models. The results indicate that the PR‐Margles mixed model can make the average absolute deviation of test data and calculated data pressure and vapor fraction less than 0.19 and 0.0025, respectively, which is superior to RK‐Margles and SRK‐Margles mixed models. Finally, an azeotropic distillation method with C2 H6 as entrainer for removing CO2 from natural gas was explored and optimized. Abstract : To remove CO2 from natural gas by azeotropic distillation, the isothermal gas‐liquid equilibrium data of binary systems of CH4, C2 H6, and CO2 obtained by previous experiments were used to verify the C2 H6 ‐CO2 azeotrope system. A new practical and economical process of azeotropic distillation decarbonization was designed and optimized, providing a theoretical basis for CO2 capture from natural gas.