Influence of Casting Solvents on CO2/CH4 Separation Using Polysulfone Membranes

Abstract

Polysulfone membranes exhibit resistance to high temperature with low manufacturing cost and high efficiency in the separation process. The composition of gases is an important step that estimates the efficiency of separation in membranes. As membrane types are currently becoming in demand for CO2/CH4 segregation, polysulfone will be an advantageous alternative to have in further studies. Therefore, research is undertaken in this study to evaluate two solvents: chloroform (CF) and tetrahydrofuran (THF). These solvents are tested for casting polymeric membranes from polysulfone (PSF) to separate every single component from a binary gas mixture of CO2/CH4. In addition, the effect of gas pressure was conducted from 1 to 10 bar on the behavior of the permeability and selectivity. The results refer to the fact that the maximum permeability of CO2 and CH4 for THF is 62.32 and 2.06 barrer at 1 and 2 bars, respectively. Further, the maximum permeability of CF is 57.59 and 2.12 barrer at 1 and 2 bars, respectively. The outcome selectivity values are 48 and 36 for THF and CF at 1 bar, accordingly. Furthermore, the study declares that with the increase in pressure, the permeability and selectivity values drop for CF and THF. The performance for polysulfone (PSF) membrane that is manufactured with THF is superior to that of CF relative to the Robeson upper bound. Therefore, through the results, it can be deduced that the solvent during in-situ synthesis has a significant influence on the gas separation of a binary mixture of CO2/CH4.

Tuning the Morphology and Gas Separation Properties of Polysulfone Membranes

“…If only slight differences in permeabilities of N 2 or CH 4 occur, the permselectivity changes significantly, due to the low values of N 2 - and CH 4 -permeabilities. Almuhtaseb et al showed even higher selectivities for PSU membranes prepared via EIPS for the gas pair CO 2 /CH 4 [ 45 ]. In their study, other solvent systems, e.g., THF and chloroform, were used, and the characterization method differs from that of this study.…”

“…If only slight differences in permeabilities of N2 or CH4 occur, the permselectivity changes significantly, due to the low values of N2and CH4permeabilities. Almuhtaseb et al showed even higher selectivities for PSU membranes prepared via EIPS for the gas pair CO2/CH4 [45]. In their study, other solvent systems, e.g., To this point, it was possible to fabricate membranes with a thin separation layer and a sponge-like support structure without obvious defects in the separation layer via the wet-phase inversion process.…”

A study of the effects of mixtures of solvents on CO2/N2 gas separation in polysulfone flat sheet membranes

“…In contrast, CO2/N2 selectivities move in a different direction depending on the solvents. Therefore, molecular size and the boiling temperature of the solvent can affect the fabricated PSF membranes, as observed in Table 4 [18]. Because the PSF membrane produced using NMP and THF had the best permeability and selectivity, the influence of the solvent in solution is discussed in the next section.…”

Membrane Fabrication for Carbon Dioxide Separation: A Critical Review

“…Therefore, this type of material has excellent oxidation resistance and thermal stability. The benzene ring improves the mechanical strength and toughness, and hence, it is acid-and alkali-resistant and not easy to be hydrolyzed [43][44][45].…”