Eutectic Freeze Cry rystallization for Treatment of f Text xtile - PowerPoint PPT Presentation

Crystallization Unit& Precipitation Research Eutectic Freeze Cry rystallization for Treatment of f Text xtile Waste Concentrates Buhle Manana Supervisor: Dr. Marcos Rodriguez-Pascual

So Sodium chloride So Sodium sulp lphate Dyes

Conventional Wastewater Treatment Water Water Reverse Evaporative Crystallization Osmosis (RO) RO Retentate Mixed salt

Eutectic Freeze Crystallization (EFC)

Eutectic Freeze Crystallization (EFC) Ic Ice Floats Sa Salts Si Sink

EFC vs. Evaporative Crystallization Researchers System Energy Savings (EFC vs. EC) % Himawan Magnesium sulphate- 60 water Nathoo et al. Sodium-sulphate water 85 Vaessen Potassium nitrate-nitric 69 acid

Ternary Diagrams

Objectives • To investigate the recovery and purity of water and sodium sulphate using EFC • Which operating temperatures should be used? • What is the recovery and purity of the products at those temperatures?

Thermodynamic modelling Component Concentration (mg/l) Ca 2+ 40 Mg 2+ 14 Component Concentration (g/l) Chloride, Cl - 28000 Sodium sulphate 14.77 Sulphate, SO 4 2- 10000 Sodium chloride 46.16 Total Silica ,SiO 2 110 Sodium as Na + 23000 Iron as Fe 3+ 0.8 HCO 3- 1640

Thermodynamic modelling

Thermodynamic Modelling

Experimental Procedure Ice Na 2 SO 4 . 10H 2 O and ice seeds Na 2 SO 4 . 10H 2 O

Results 500 450 400 350 Ice recovery (g) 300 250 OLI results 200 Experimental 150 100 50 0 -7 -6.5 -6 -5.5 -5 -4.5 -4 -3.5 -3 -2.5 -2 Temperature ( o C)

Results 30 25 20 Salt Recovery (g) 15 OLI results Experimental 10 5 0 -7 -6.5 -6 -5.5 -5 -4.5 -4 -3.5 -3 -2.5 -2 Temperature ( o C)

Discussion Ice crystal Salt crystal Settling of v salt crystals

Results ENERGY REQUIREMENTS FOR WATER PURIFICATION 3000 2500 Energy (kJ/Kg) 2000 1500 1000 500 0 EFC Evaporative crystallization

Conclusion • EFC can recover salts and water from ternary system with high purity • Lower energy costs

Recovery of Anhydrous salt Anhydrous salt recovery (%) Experimental maximum from OLI 17.3 29.4 41.2 64.1 51.3 80.0 Crystallization & Precipitation Unit

Energy Requirements exp number sensible ice formation salt formation losses 1 14389 41989 4060 27000 2 17007 97892 9771 37800 3 14577 136340 12160 37800 average 15324 92074 8664 34200 Crystallization & Precipitation Unit

Experimental data Salt Recovery at -3.6 o C water recovery at -3.6 o C sodium sulphate decahydrate recovery (g) 12 160 10 140 120 8 water recovery (g) 100 6 80 Series1 60 4 40 2 20 0 0 OLI exp1 exp2 exp3 OLI exp1 exp2 exp3 Crystallization & Precipitation Unit