Experimental Study on MDEA Regeneration by Vacuum Membrane Distillation

2013 ◽  
Vol 726-731 ◽  
pp. 2691-2694
Author(s):  
Shi Dong Zhou ◽  
Shuang Shuang He ◽  
Zhi Min Wu ◽  
Shu Li Wang
Keyword(s):  
Experimental Study ◽  
Aqueous Solutions ◽  
Membrane Distillation ◽  
Solution Temperature ◽  
Waste Solution ◽  
Experimental Conditions ◽  
Vacuum Membrane Distillation ◽  
Regeneration Efficiency

Aqueous solutions of N-methyldiethanolamine (MDEA) are widely used in the sweetening process of sour gases, but the solutions deteriorate due to the contamination in their use process, and the deficiencies of the technologies for the regeneration of disabled solution restrict their development. A vacuum membrane distillation (VMD) technique for the regeneration of MDEA solutions was proposed and experimentally investigated.It is studied the effect of change in solution temperature on its regeneration efficiency and the distillation flux. From the chromatograms it is known that the best temperature for regenerating waste solution by VMD is 70 °C,and the regeneration efficiency can be up to 98% at this experimental conditions.

scholarly journals An Experimental and Theoretical Study on Separations by Vacuum Membrane Distillation Employing Hollow-Fiber Modules

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 947 ◽  
Author(s):  
Anthoula Karanasiou ◽  
Margaritis Kostoglou ◽  
Anastasios Karabelas
Keyword(s):  
Process Model ◽  
Flow Direction ◽  
Membrane Distillation ◽  
Water Desalination ◽  
Solution Temperature ◽  
Feed Water ◽  
System Productivity ◽  
Capillary Membrane ◽  
Vacuum Membrane Distillation ◽  
By Products

Vacuum membrane distillation (VMD) is an attractive variant of the novel membrane distillation process, which is promising for various separations, including water desalination and bioethanol recovery through fermentation of agro-industrial by-products. This publication is part of an effort to develop a capillary membrane module for various applications, as well as a model that would facilitate VMD process design. Experiments were conducted in a laboratory pilot VMD unit, comprising polypropylene capillary-membrane modules. Performance data, collected at modest temperatures (37 °C to 65 °C) with deionized and brackish water, confirmed the improved system productivity with increasing feed-water temperature; excellent salt rejection was obtained. The recovery of ethanol from ethanol-water mixtures and from fermented winery by-products was also studied, in continuous, semi-continuous, and batch operating modes. At low-feed-solution temperature (27–47 °C), ethanol-solution was concentrated 4 to 6.5 times in continuous operation and 2 to 3 times in the semi-continuous mode. Taking advantage of the small property variation in the module axial-flow direction, a simple VMD process model was developed, satisfactorily describing the experimental data. This VMD model appears to be promising for practical applications, and warrants further R&D work.

A new sand adsorbent for the removal and reuse of nickel ions from aqueous solutions

2017 ◽  
Vol 75 (8) ◽  
pp. 1812-1819 ◽  
Author(s):  
Wenhong Tao ◽  
Ling Qi ◽  
Huimin Duan ◽  
Shiquan Liu
Keyword(s):  
Aqueous Solutions ◽  
Removal Efficiency ◽  
Solution Temperature ◽  
Porous Coating ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Experimental Conditions ◽  
Nickel Ions ◽  
Order Kinetic Model ◽  
Ph Range

Nickel ions (Ni(II)) in aqueous solutions were removed by a sand adsorbent with a surface functionalized porous coating. The sand adsorbent has a very large surface area of 150 m2/g. The influence of pH, initial concentration of the solution, temperature, contact time and adsorbent dosage on the removal efficiency of the synthesized sand adsorbent toward Ni(II) in the aqueous solutions were studied. The results indicate that the adsorption of nickel onto the sand adsorbent greatly increases the pH range of 2–4 and slightly increases with temperature from 25 to 40 °C. The maximum removal efficiency and ion retention in per unit mass of the adsorbent were 100% and 5.78 mg/g, respectively, under the specified experimental conditions. The adsorption can be described by the pseudo-second-order kinetic model and the Freundlich adsorption model. The adsorbed nickel (4.24 mg/g) together with the spent adsorbent were successfully employed to prepare a brown glass, suggesting a new way to reutilize the recovered nickel from wastewater and to avoid secondary pollution caused by the used adsorbents.

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