Dual mode model for mixed gas permeation of CO₂, H₂, and N₂ through a dry chitosan membrane

Abstract

Dry chitosan is an excellent candidate for facilitated transport membranes that can be utilized in industrial applications, such as fuel cell operations and other purification processes. This article is the first to report temperature effects on transport properties of CO2, H2, and N2 in a gas mixture typical of such applications. At a feed pressure of 1.5 atm, CO2 permeabilities increased (0.381–26.1 barrers) at temperatures of 20–150 °C with decreasing CO2/N2 (19.7–4.55) and CO2/H2 (3.14–1.71) separation factors. The pressure effect on solubilities and permeabilities were fitted to the extended dual mode model and its corresponding mixed gas permeation model. The dual mode and transport parameters, the sorption heats and the activation energies of Henry's and Langmuir's regimes and their pre‐exponential parameters were determined. The Langmuir's capacity constants were utilized to estimate chitosan's glass transition temperature (CO2: 172 °C, N2: 175 °C, and H2: 171 °C). The activation energies of diffusion in the Henry's law and Langmuir regimes were dependent on the collision diameter of the gases. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2620–2631, 2007

Hybrid Ionic Liquid-Chitosan Membranes for CO2 Separation: Mechanical and Thermal Behavior

“…The RTIL enhances the CO 2 affinity of the membrane material and reduces the influence of temperature in diffusivity and, therefore, permeability. These values validate the solution-diffusion model [5,11].…”

“…As expected, the CO 2 sorption decreases with temperature [11], while the diffusivity increases with temperature, which corresponds to the permeability decrease with temperature in Figure 5(A).…”

“…The experimental results are compared in terms of the activation energies with a previous work [5] where [emim] [Ac] based SILMs were evaluated on CO 2 /N 2 separation, as well as reported literature on pure CS membranes [11]. The activation energies for permeation, sorption and diffusion are given in Table 2.…”

Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation

“…Void symbols represent the membranes where CS is the continuous phase, filled symbols those where the continuous phase is constituted by IL/CS. Dense CS, IL, and ETS-10 are literature pair values for dense CS membranes [38], supported [emim][Ac] membranes on a porous PVDF disk [22] and pure ETS-10 inorganic membranes on porous alumina supports [21], respectively.…”

Chitosan membrane in separation applications

“…176,177 With the existence of basic amino groups in the polymer chain, CS is expected to allow the selective permeation of CO 2 . Though CS membranes in dry conditions may also possess such selectivity, 178 the permeation is quite low owing to the rigid structure. 179 Water acting as the plasticiser may significantly alter the gas permeation properties of CS.…”