Resin screening for solvent impregnated resins in industrial wastewater treatment applications

Transcription

1 Resin screening for solvent impregnated resins in industrial wastewater treatment applications J. Bokhove MSc. Dr. Ir. B. Schuur Prof. Dr. Ir. A.B. de Haan Eindhoven University of Technology Process Systems Engineering EPIC, Manchester

2 Outline Introduction Objective Approach Experimental results Resin selection Fixed bed experiments Conclusions PAGE 1

3 Introduction Trace removal Concentrations ~ 1000 ppm impurities to < 10 ppm Novel technologies are desired Case study: wastewater treatment Pyridine derivatives (500 ppm) Organic acids (4.5 g/l) Removal of pyridine derivatives Technologies: Adsorption High capacity Difficult regeneration Extraction High capacity Entrainment/emulsification PAGE 2 4-Cyanopyridine Acetic acid Solvent Impregnated Resins

4 Solvent Impregnated Resins Advantages High capacity Easier regeneration Minimized entrainment Disadvantage Leaching of the solvent PAGE 3

5 Solvent impregnated resins Originates from analytical chemistry First publication on separations of metals 1972 First industrial application MPPE AKZO-Nobel, now Veolia Extraction of hydrocarbons from off-shore wastewater Reactive extraction of polar organic compounds first 2008 Aldehydes from water Phenols, MTBE, etc. PAGE 4

6 Objective Design a solvent impregnated resin for the trace removal of 4-cyanopyridine from an aqueous stream containing acetic acid with minimized leaching of the solvent 4-Cyanopyridine Acetic acid PAGE 5

7 Approach A. Solvent design High capacity/selectivity Low solubility in water B. Resin selection Capacity/selectivity Mass-transfer rates PAGE 6

8 Approach A. Solvent design High capacity/selectivity Low solubility in water B. Resin selection Capacity/selectivity Mass-transfer rates C. Fixed bed column studies Breakthrough profiles Stability D. Process design Cost estimation Feasibility study PAGE 7

9 Approach: Resin selection Matrix type None-Functional Aromatic functionalized Chemical functionalized Dimensions Diameter: 50 micrometer 1 mm Pore diameter 3 nm 300 nm Porosity 30 % - 60 % SIR Preparation Resin + 4-Nonylphenol diluted in n-hexane Evaporation of hexane Loading of the solvent by a mass-balance PAGE 8

10 Experimental procedures Capacity and selectivity Mass-transfer Zero length column setup Estimate the mass-transfer coefficient Fixed bed column experiments Length 30 cm Diameter 1.5 cm Breakthrough when C effluent > 1 % of C Feed PAGE 9

11 Experimental results Resin selection Capacity and selectivity Mass-transfer rates Fixed bed studies Breakthrough curves Regeneration Stability PAGE 10

12 Results Resin Selection Highest capacity, but low mechanical strength None-functional Chemically functionalized Aromatic PAGE 11

13 Results Resin selection Selectivity Selectivity comparable to the solvent (S = 150) PAGE 12

14 Results Resin selection Low capacity, but good mass-transfer Commercially applied Good capacity, reasonable mass-transfer None-functional Chemically functionalized Aromatic PAGE 13

15 Results Resin Selection Final resin selection d p (mm) ε p (-) MPP 1 mm 0.6 Amberlite XAD4 0.5 mm 0.5 Supelite DAX mm 0.4 Important parameters Pressure drop Column length and particle size Capacity Volume of the bed and porosity Effective use of capacity Column length and mass-transfer rate Process Systems Engineering PAGE 14

16 Results Resin Selection Pressure drop Maximum = 0.7 bar d p (mm) ε p (-) MPP 1 mm 0.6 Amberlite XAD4 0.5 mm 0.5 Supelite DAX mm 0.4 Process Systems Engineering PAGE 15

17 Results Resin Selection Fixed-bed capacity d p (mm) ε p (-) MPP 1 mm 0.6 Amberlite XAD4 0.5 mm 0.5 Supelite DAX mm 0.4 Process Systems Engineering PAGE 16

18 Results Resin Selection Effective use of capacity d p (mm) ε p (-) MPP 1 mm 0.6 Amberlite XAD4 0.5 mm 0.5 Supelite DAX mm 0.4 Process Systems Engineering PAGE 17

19 Results Resin Selection Operating time d p (mm) ε p (-) MPP 1 mm 0.6 Amberlite XAD4 0.5 mm 0.5 Supelite DAX mm 0.4 Final selection was Amberlite XAD4 Highest capacity Sufficient mass-transfer Optimal particle diameter Process Systems Engineering PAGE 18

20 Experimental results Resin selection Capacity and selectivity Mass-transfer rates Fixed bed studies Breakthrough curves Regeneration Stability PAGE 19

21 Results Fixed bed studies Breakthrough profiles loading Bed Height = 29 cm Diameter = 1.5 cm C feed = 500 ppm --- Q v = 1 ml/min --- Q v = 2.5 ml/min --- Q v = 5 ml/min C effluent /C feed ~ 0.01 after 1 8 bed volumes Intersection at 20 BV, agreeing with equilibrium Full saturation after ~ 55 BV PAGE 20

22 Results Fixed bed studies Regeneration Efficient and complete regeneration by ph-swing Factor 10 increase in concentration PAGE 21

23 Results Fixed bed studies Stability measurements After 7000 bed volumes no decrease in capacity 350 L water through a 50 ml column PAGE 22

24 Results Overall performance How do SIRs fit in Process Intensification 50 % higher capacity on volume basis Process Systems Engineering PAGE 23

25 Conclusions A resin was selected for a SIR containing 4-nonylphenol Selectivity and capacity determined by the solvent Capacity 13 g/kg at 500 ppm 4-cyanopyridine Fixed bed column experiments were performed Mass-transfer limitations result in a wide breakthrough Regeneration by ph swing is effective SIR of Amberlite XAD4 and 4-nonylphenol is highly stable The SIR had a capacity 50 % higher on volume basis PAGE 24

26 Acknowledgements Institute of Sustainable Process Technology