Desorption kinetic study of mercury species in spent mercury chloride catalyst from polyvinyl chloride production process. Issue 5 (3rd March 2019)

• Record Type: Journal Article
• Authors: Liu, Peng; Liu, Chao; Li, Shiwei; Liu, Bingguo; Shi, Junjie; Zhang, Libo; Peng, Jinhui
• Is Part Of: Environmental progress & sustainable energy. Volume 38:Issue 5(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-03-03
• Subjects: spent mercury chloride catalyst -- mercury desorption -- non‐isothermal kinetics -- diffusion process; Environmental engineering -- Periodicals; Sustainable engineering -- Periodicals; Environmental chemistry -- Periodicals; 333.7
• DOI: 10.1002/ep.13201
• Languages: English
• ISSNs: 1944-7442

Abstract

Abstract : In order to improve the hazard‐free treatment and comprehensive utilization of the spent chloride mercury catalysts, reaction kinetics, and diffusion process of the thermal desorption of mercury were investigated. For reaction kinetics, activation energy of the reactions in the temperature range 436.15–694.15 K was calculated by five different model‐free methods, among which, FWO (105.47 kJ·mol −1 ) model‐free method with the best fitting precision was applied as the parameter to deduce the reaction models and describe the kinetic mechanism. It was confirmed that three diffusion models (D1, D2, D3) dominated at the beginning/middle of the reactions and one reaction order model (F2) dominated at the later part. According to the deduced mechanism, diffusion enhancing and reaction temperature enhancing strategies were introduced. For diffusion process of mercury volatiles, the laminar state of the protective gas was confirmed when the nitrogen flow rate is 100 L/h; based on the boundary simplifications, the thickness and the pressure difference of the boundary layer were calculated. According to the results of pressure difference, mercury diffusion process has two stages: Higher pressure diffusion stage and Residual mercury removal stage. Reaction kinetics and diffusion calculation give a better understanding of the mercury removal process and the parameters obtained in this work are useful to design the reactor. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019