Monoethylene glycol (MEG) aqueous solution was regenerated in the forward osmosis (FO) process for further use. For this purpose, a novel thin-film composite (TFC) membrane was prepared and applied. To mitigate the internal concentration polarization (ICP), a proper support with a low structural parameter and high hydrophilicity was utilized. In addition, a chlorine-tolerant polyamide layer was synthesized using trimesic acid trichloride (TMC) and 4-methyl-m-phenylenediamine (MMPD) monomers. The latter aimed to improve the chlorine resistance of the polyamide layer and increase the membrane lifespan in practical applications where oxidants are utilized for membrane cleaning. The effect of MMPD concentration and interfacial polymerization (IP) reaction time on the characteristics of the top layer was studied thoroughly. During the FO test, the TFC membrane whose polyamide layer was prepared with 2 wt. % MMPD concentration and 1.4 min reaction time exhibited the highest reverse flux selectivity at 5.71 L/g, while its water flux and MEG rejection during the regeneration of a MEG aqueous solution sampled from a gas processing plant were 35.40 LMH and 93.85%, respectively. The chlorine exposure test confirmed a significantly higher chlorine resistance for the MMPD/TMC polyamide layer compared to the conventional MPD/TMC one.

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