Adsorption Desalination and its hybrids
Transcription
Adsorption Desalination and its hybrids
9/17/2015 Adsorption Desalination and its hybrids: Cycle simulation and Experiments The Sorption meeting at Milazzo, Sicily, Italy 14-16th September 2015 Online and contracted plants & capacities in GCC countries 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy 1 9/17/2015 Types of Practical desalination plants Reverse Osmosis (RO) – good energy efficiency – 3.5 to 7.5 kWhelec/m3, but sensitive to SDI, HABs. High operating cost – membrane replacement, pre-treatment Thermally-activated cycles:- colocated with power plants, exploits low exergy steam to power MED/MSF/AD cycles. Conventional MED/MSF design has GOR from 9 to 12 . GOR can improve to >20 by better process design & hybridization 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy Challenges facing RO membrane processes: HABs Gulf water storage capacity is only 5-7 days Sorption meeting, Milazzo, Sisli Italy 14-16 Sep 2015 - high silt, HAB – bloom of dinoflagellate (red tides); toxins cause illness and death are the primary impact 2 9/17/2015 Q, in TBT 70oC ΔT for MEDAD operation MED operation limit 30oC Condenser Cooling tower operation limit 70oC Condenser Stage-n 40oC Soft Scaling removed by NF TBT 70oC Stage-1 ΔT for MED operation Stage-1 Corrosion issues Q, in 40oC Operational regime of Conventional MED, GOR < 12 Ambient limit 30oC Q, out Stage-n 5oC Conventional MED – 6 to 8 stages. MED-AD hybrid can have up to 14 stages. 5oC AD cycle operation below ambient Operational regime of hybrid cycles Q, in 125oC Sorption meeting, Milazzo, Sisli,Italy Advanced hybrid cycle can be arranged to operate between a TBT=125o C and a BBT =5o C, giving a total of 20 or more recoveries as compared to 8-10 in conventional plants 14-16 Sep 2015 MED/MSF: Limitations and solutions *Leon Awerbuch, Integrated Hybrid Desalination Systems, proceeding of IDA World Congress, Canary Island, 2007 (http://gwri-ic.technion.ac.il/pdf/IDS/124.pdf) **K. Thu, K.C. Ng, B.B. Saha, A. Chakraborty, S. Koyama, Operational strategy of adsorption desalination systems, International Journal of Heat and Mass Transfer, 52 (2009) 1811-1816 Adsorbent (SiO2..nH2O) Characteristics Properties Pore size(nm) Porous volume (cm3.g-1) Surface area (m2.g-1) Value 0.8-7.5 0.476 863.6 Average pore diameter (nm) 2.2 Apparent density (kg.m-3) pH (-) Specific heat capacity (kJ.kg-1.K-1) Thermal conductivity (W.m-1.K-1) 700 4.0 0.921 0.198 Pore Volume (cm3/g) Pore width (Å) Type-A5BW Type-RD 2560 0.446 0.314 30.60 24.25 Type-A++ 0.476 30.60 Type of Silica Gel Thu et al., Applied Thermal Engineering, 2013. 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy 3 9/17/2015 Adsorption desalination cycle (thermallyactivated) 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy Solar-powered adsorption cool cum desalination pilot plant for KAUST Hot water tanks Collectors Radiator T4 T3 T2 T1 Auxiliary heater Condenser T Cooling water tank T T P T T Potable water tank Cooling tower T T Cooling energy T T T Sea water tank P Evaporator 14-16 Sep 2015 Sorption meeting, Milazzo, Sicily,Italy 4 9/17/2015 - Solar Thermal Monthly average daily radiation from theory and NSA SSE • • Monthly average daily extraterrestrial radiation and monthly average daily radiation on a horizontal surface Solar radiation absorbed on the tilted surface for flat plate solar collector with isotropic diffuse model S I b R b I d 1 cos I h g 2 Sisli,Italy Sorption meeting, Milazzo, b d g 1 cos 2 KAUST Pilot – design commenced from 2009 and completed in 2011, seawater trials until now. Condenser PLC controller Evaporator (Stainless steel) Vacuum Adsorber Cooling water in bed Hot water in Hot water pump Air compressor Spray pump out Chilled in/out Cooling water water out 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy 5 9/17/2015 Performance of ADC cycles Cycles are configured for various operational modes without any physical or hardware changes. Operation modes: (1) Desalination only mode (2) Desalination and cooling (chilled water @ 7.5 °C) (3) Desalination and cooling (chilled water @ 20 °C) Ng et al., International Journal of Refrigeration, 2013. Thu et al., International Journal of Heat and Mass Transfer, 2009. 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy Salinity of water in evaporator (Conducted at the Analytical Core Labs of KAUST) Seawater (Red Sea) Samples from evaporator Parameters 19S2 13S4 20S5 (40% (60% (80% Recovery) recovery) recovery) 64.49 100.73 110.28 6027 9930 17527 28974 pH (NA) 8.24 8.21 8.06 7.81 TN (ppm) 0.06 0.14 0.15 0.36 analysed 13S1 Alkalinity (mg/L) 39.47 Total Hardness (mg/L) TOC (ppm) 0.63 1.28 1.86 3.8 TDS (mg/L) 37,408 64,320 108,704 210,240 Turbidity (NTU) 6.59 7.17 6.14 31.3 Conductivity (μS/cm) 53100 84100 129600 193400 Boron (ppm) 4.57 7.69 13.82 25.61 Calcium (ppm) 393.04 794.97 1149.35 1029.41 Chloride (ppm) 20715 35590 62411 120515 Iron (ppm) 0.88 1.72 1.53 5.2 Silica (mg/L) 0.58 0.69 1.17 1.67 Magnesium (ppm) 1266.83 2232.67 3785.24 7331.49 Manganese (ppm) 0.06 0.14 0.12 0.42 Sodium (ppm) 10707.6 20481.2 37525.6 74292.4 Bromide (ppm) 64.29 117.27 208.92 419.14 Sulfate (ppm) 2914 5095 8529 13088 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy 6 9/17/2015 AD pilot fed by Red Seawater – Product water Quality AD Water (Output) Samples Parameter analysed EPA standards (drinking water) Maximum Contaminant Level (MCL) (mg/L) AD Water (Output) Samples Parameter analysed 13A2 19A1 20A1 0.006 0.02 ND 0.0004 0.023 0.013 0 0.013 250 6.5-8.5 ND 0.0054 ND ND 0.1 0.37 - 0.1 0.1 0.07 0.09 1 0.01 0.01 - 0.02 0.06 0.003 0.005 0.3 0.22 0.2 0.23 - ND 0.01 ND ND ‐ 0 0 0 500 0.002 0.008 0.0002 0.002 ‐ 0.11 0.04 0.07 0.02 - 0.002 0.005 0.0002 ND 0.05 4 6 2 2 Type III DI 0.01 0.006 0.001 0.02 30‐60 ND 0.009 ND ND 0.05-0.2 ND ND ND ND ‐ ND ND ND ND 2 0.004 0.005 0.005 0.004 2 13A1 13A2 19A1 20A1 ND ND ND ND - 0 0 0 ND - 5.73 6.05 5.56 5.42 0.31 0.32 0.26 0.06 0.01 0.31 0 13A1 EPA standards (drinking water) Maximum Contaminant Level (MCL) (mg/L) ND ND 0.002 ND - 0.002 0.003 ND ND 10 ND 0.003 0.002 ND 0.005 0.026 0.027 0 0.028 250 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy For sustainable Desalination: - Hybridization conceptAD+MED cycles that exploits thermodynamic synergy Low-temperature heat sources (50–85 °C) Robust to feed quality variation (300 ppt or more) ADC Cycle Potable water (< 10 ppm) Cooling power (5–25 °C) High TDS discharge (> 300 ppt) 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy 7 9/17/2015 Example of integrating AD and the MED: Schematic of a 3-stage MED+AD or MEAD cycle 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy Experiments - 3-stage MED+AD pilot 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy 8 9/17/2015 Measured temperature & water production rates of a 3-stage MEAD cycle Thot,in 1.6 TSG Distillate production (LPM) 50 Thot,out Temperature (C ) 45 40 35 AD ME‐AD total ME‐AD Avg Prod 1.2 0.8 0.4 Adsorption effect‐temperature pull down once MED and AD integration valve is opened 30 MED 25 0.0 0 2000 4000 6000 8000 10000 0 2000 Basic AD water production= 0.56 L/m, 14-16 Sep 2015 4000 6000 8000 10000 Time (sec) Time (sec) and a 3-stage hybrid MEAD =1.15 L/m Sorption meeting, Milazzo, Sisli,Italy Prediction of temperature and water production rates of a 8-stage MEAD with a heat input (45 kWthermal). Water production = 5.5 L/m, PR =4.8 14-16 Sep 2015 Sorption meeting, Milazzo, Sisli,Italy 9 9/17/2015 Hybridization improves the PR: A Kudus to Thermodynamic Synergy Types of pilot plant Average water production (LPM) Basic AD Cycle 0.56 Energy input (kW_th) 42 ±0.5 PR = ∑ 0.52±0.05 ME-AD (3 stageExperiment) 1.15 45.0 ± 0.5 1.1±0.05 MEAD (simulation at 8 stages) 5.5 45.0 ± 0.5 4.8±0.05 Sorption meeting, Milazzo, Sisli,Italy Conclusion AD is highly efficient in utilizing low temperature heat sources – up to 80oC, Hybrid with other thermally-driven cycles, improves water production by several folds, AD offers a sustainable low-energy solution to desalination and cooling, Hybrid approaches to design are environment friendly - it addresses the needs to have a energy-water-environment nexus. Sorption meeting, Milazzo, Sisli,Italy 10