Phenol recovery from different aqueous solutions (industrial wastewater and process water) is of wide interest from environmental and industrial point of view. Among the various recovery processes some of them involving membranes are described in the following. The recovery of phenol from aqueous solutions with CYANEX (R) 923 was studied by Cichy et al. (2001). Classical dispersive extraction and three membrane extraction-stripping systems (bulk liquid membranes, three-phase hollow fiber contactor and two hollow fiber modules set-up) were used. It was found that CYANEX (R) 923 was a convenient carrier for recovery of phenol from aqueous streams in extraction-stripping membrane processes. The problem of emulsion formation, so important in dispersive extraction, was avoided. Both mass transfer experiments in different membrane systems and measurement of the dynamic interfacial tension demonstrated importance of the interfacial phenomena occurring in the stripping stage. A blocking of this interface was observed that resulted in a decrease of phenol mass transfer. Pertraction of dimethylcyclopropanecarboxylic acid (DMCCA) and phenol in a new hollow-fiber (HF) contactor of three liquid phases with distributed U-shaped bundles of microporous HF was studied by Schlosser et al (2002). Trioctylamine (TOA), Hostarex A327 and Cyanex 47 1 X have been used as carriers. The performance of this contactor is similar to other HF contactors. Its advantage is that both bundles of fibers can elongate without deformation of fibers and maldistribution of fibers in the bundles. Pulsation of the membrane phase increases the transport rate by 35-61% and it reaches a plateau value at the pulsation velocity of about 1.1 mm·s-1. With increasing velocity of the feed in the fiber lumen the value of the overall mass-transfer coefficient increases, but soon a steady value is approached at the velocity of about 5.5 cm·s-1. The diffusion resistances in a series model do not describe the pertraction of DMCCA well. The suggested new diffusion-reaction model, considering the resistance based on the kinetics of the stripping reaction, fits experimental data well. Not only the rate of the acid-carrier complex decomposition, but also that of the DMCCA dimer decomposition have to be considered. The estimated values of the apparent reaction rate constant were for the membrane with TOA 1.91·10-6 m·s-1 and for pure n-alkanes 5.78·10-6 m·s-1.The kinetic resistance on the stripping interface represents 20-60% of the overall mass-transfer resistance and its value is comparable to the diffusion resistance of both walls. Application of membrane techniques (pervaporation and membrane-based solvent extraction) and adsorption to the removal of phenol from solutions modelling wastewater from phenol production by cumene oxidation process was investigated by Kujawski et al (2004). The transport and separation properties of composite membranes PEBA, PERVAP 1060 and PERVAP 1070 in pervaporation of water-phenol mixtures were determined. It was found that the best removal efficiency of phenol was obtained using the PEBA membrane. MTBE, cumene and the mixture of hydrocarbons were applied in the membrane-based phenol extraction. Extra-Flow contactor with Celgard X-30 polypropylene hollow-fiber porous membranes was used in the experiments. MTBE was found the most efficient extractant. Adsorption of phenol on the different Amberlite resins was also investigated. Among the Amberlite resins of various grades used, the Amberlite XAD-4 had the best properties in the phenol removal from the aqueous solutions. It was shown that regeneration of the adsorbent bed could be effectively performed with sodium hydroxide solution. The extraction and stripping of phenol using a solution of tributyl phosphate in kerosene in a hydrophobic polypropylene hollow fiber membrane contactor was studied by Shen et al (2009). The effect of the aqueous and the organic phase flow rates on the overall mass transfer coefficient for both extraction and stripping steps was investigated. Experimental values of the overall mass transfer coefficient were determined and compared with predicted values from the resistance in series model. Results showed that the overall mass transfer coefficients for extraction were about one order of magnitude greater than those measured during the stripping process. The experimental values were in good agreement with the predicted values for the extraction module. However, the predicted values were slightly overestimated for the stripping module. The individual mass transfer resistances were analyzed and the rate-controlling steps of mass transfer were also identified in both extraction and stripping modules. The major resistance in extraction and stripping was in the aqueous phase and in the membrane phase, respectively. The removal of phenols from wastewater has been investigated under various operational conditions using hydrophobic hollow fiber membrane contactors (Shen et al 2012). Experimental overall mass transfer coefficients were obtained in both handmade and Liqui-Cel™ modules. Model predictions based on a resistance in series model with solvent-filled membrane pores matched well with experimental values for tributyl phosphate/Shellsol extraction systems. However, the predictions were in poor agreement with experimental data obtained when 50% pentanol/xylene was used to treat industrial wastewater in the handmade module. Further analysis showed that the operational pressure on the aqueous side and the breakthrough pressure for the two solvents probably influenced the position of the interface within the membrane pores. This change in wetting patterns resulted in significant differences in mass transfer and solute recovery which can be accounted for by adjusting the position of the interface within the membrane fiber. References Cichy W, Schlosser S, Szymanowski J (2001) Recovery of phenol with CYANEX((R)) 923 in membrane extraction-stripping systems. Solvent Extraction and Ion Exchange 19:905-923 Kujawski W, Warszawski A, Ratajczak W, Porebski T, Capala W, Ostrowska I (2004) Removal of phenol from wastewater by different separation techniques. Desalination 163:287-296 Shen SF, Smith KH, Cook S, Kentish SE, Perera JM, Bowser T, Stevens GW (2009) Phenol recovery with tributyl phosphate in a hollow fiber membrane contactor: Experimental and model analysis. 69:48-56 Shen SF, Kentish SE, Stevens GW (2012) Effects of operational conditions on the removal of phenols from wastewater by a hollow-fiber membrane contactor. Separation and Purification Technology 95:80-88 Schlosser S, Sabolova E (2002) Three-phase contactor with distributed U-shaped bundles of hollow-fibers for pertraction. Journal of Membrane Science 210:331-347
Phenol recovery using membrane contactor
MOLINARI, Raffaele
2013-01-01
Abstract
Phenol recovery from different aqueous solutions (industrial wastewater and process water) is of wide interest from environmental and industrial point of view. Among the various recovery processes some of them involving membranes are described in the following. The recovery of phenol from aqueous solutions with CYANEX (R) 923 was studied by Cichy et al. (2001). Classical dispersive extraction and three membrane extraction-stripping systems (bulk liquid membranes, three-phase hollow fiber contactor and two hollow fiber modules set-up) were used. It was found that CYANEX (R) 923 was a convenient carrier for recovery of phenol from aqueous streams in extraction-stripping membrane processes. The problem of emulsion formation, so important in dispersive extraction, was avoided. Both mass transfer experiments in different membrane systems and measurement of the dynamic interfacial tension demonstrated importance of the interfacial phenomena occurring in the stripping stage. A blocking of this interface was observed that resulted in a decrease of phenol mass transfer. Pertraction of dimethylcyclopropanecarboxylic acid (DMCCA) and phenol in a new hollow-fiber (HF) contactor of three liquid phases with distributed U-shaped bundles of microporous HF was studied by Schlosser et al (2002). Trioctylamine (TOA), Hostarex A327 and Cyanex 47 1 X have been used as carriers. The performance of this contactor is similar to other HF contactors. Its advantage is that both bundles of fibers can elongate without deformation of fibers and maldistribution of fibers in the bundles. Pulsation of the membrane phase increases the transport rate by 35-61% and it reaches a plateau value at the pulsation velocity of about 1.1 mm·s-1. With increasing velocity of the feed in the fiber lumen the value of the overall mass-transfer coefficient increases, but soon a steady value is approached at the velocity of about 5.5 cm·s-1. The diffusion resistances in a series model do not describe the pertraction of DMCCA well. The suggested new diffusion-reaction model, considering the resistance based on the kinetics of the stripping reaction, fits experimental data well. Not only the rate of the acid-carrier complex decomposition, but also that of the DMCCA dimer decomposition have to be considered. The estimated values of the apparent reaction rate constant were for the membrane with TOA 1.91·10-6 m·s-1 and for pure n-alkanes 5.78·10-6 m·s-1.The kinetic resistance on the stripping interface represents 20-60% of the overall mass-transfer resistance and its value is comparable to the diffusion resistance of both walls. Application of membrane techniques (pervaporation and membrane-based solvent extraction) and adsorption to the removal of phenol from solutions modelling wastewater from phenol production by cumene oxidation process was investigated by Kujawski et al (2004). The transport and separation properties of composite membranes PEBA, PERVAP 1060 and PERVAP 1070 in pervaporation of water-phenol mixtures were determined. It was found that the best removal efficiency of phenol was obtained using the PEBA membrane. MTBE, cumene and the mixture of hydrocarbons were applied in the membrane-based phenol extraction. Extra-Flow contactor with Celgard X-30 polypropylene hollow-fiber porous membranes was used in the experiments. MTBE was found the most efficient extractant. Adsorption of phenol on the different Amberlite resins was also investigated. Among the Amberlite resins of various grades used, the Amberlite XAD-4 had the best properties in the phenol removal from the aqueous solutions. It was shown that regeneration of the adsorbent bed could be effectively performed with sodium hydroxide solution. The extraction and stripping of phenol using a solution of tributyl phosphate in kerosene in a hydrophobic polypropylene hollow fiber membrane contactor was studied by Shen et al (2009). The effect of the aqueous and the organic phase flow rates on the overall mass transfer coefficient for both extraction and stripping steps was investigated. Experimental values of the overall mass transfer coefficient were determined and compared with predicted values from the resistance in series model. Results showed that the overall mass transfer coefficients for extraction were about one order of magnitude greater than those measured during the stripping process. The experimental values were in good agreement with the predicted values for the extraction module. However, the predicted values were slightly overestimated for the stripping module. The individual mass transfer resistances were analyzed and the rate-controlling steps of mass transfer were also identified in both extraction and stripping modules. The major resistance in extraction and stripping was in the aqueous phase and in the membrane phase, respectively. The removal of phenols from wastewater has been investigated under various operational conditions using hydrophobic hollow fiber membrane contactors (Shen et al 2012). Experimental overall mass transfer coefficients were obtained in both handmade and Liqui-Cel™ modules. Model predictions based on a resistance in series model with solvent-filled membrane pores matched well with experimental values for tributyl phosphate/Shellsol extraction systems. However, the predictions were in poor agreement with experimental data obtained when 50% pentanol/xylene was used to treat industrial wastewater in the handmade module. Further analysis showed that the operational pressure on the aqueous side and the breakthrough pressure for the two solvents probably influenced the position of the interface within the membrane pores. This change in wetting patterns resulted in significant differences in mass transfer and solute recovery which can be accounted for by adjusting the position of the interface within the membrane fiber. References Cichy W, Schlosser S, Szymanowski J (2001) Recovery of phenol with CYANEX((R)) 923 in membrane extraction-stripping systems. Solvent Extraction and Ion Exchange 19:905-923 Kujawski W, Warszawski A, Ratajczak W, Porebski T, Capala W, Ostrowska I (2004) Removal of phenol from wastewater by different separation techniques. Desalination 163:287-296 Shen SF, Smith KH, Cook S, Kentish SE, Perera JM, Bowser T, Stevens GW (2009) Phenol recovery with tributyl phosphate in a hollow fiber membrane contactor: Experimental and model analysis. 69:48-56 Shen SF, Kentish SE, Stevens GW (2012) Effects of operational conditions on the removal of phenols from wastewater by a hollow-fiber membrane contactor. Separation and Purification Technology 95:80-88 Schlosser S, Sabolova E (2002) Three-phase contactor with distributed U-shaped bundles of hollow-fibers for pertraction. Journal of Membrane Science 210:331-347I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
