Forward Osmosis Applied to Desalination and Evaporative Cooling Make-up Water

Transcription

1 Forward Osmosis Applied to Desalination and Evaporative Cooling Make-up Water 3 rd Osmosis Summit 26/27 April 2012 Bringing new technology to the water industry

2 Outline What use is Forward Osmosis? Forward Osmosis Desalination FO and Evaporative Cooling Towers Summary Bringing new technology to the water industry 2

3 What use is FO? Operates at low pressure, typically 0 3 barg Can concentrate one stream with a lower osmotic pressure using another of higher osmotic pressure Dilute a more concentrated stream with a lower concentrated stream Particular advantages with difficult feed waters Applications: Emergency drinks from brackish or sea water Power generation Enhanced oil recovery Fracture water Thermal desalination feedwater softening Desalination Water substitution Source HTI 2. Source Statkraft Bringing new technology to the water industry 3

4 Forward Osmosis and Desalination Bringing new technology to the water industry 4

5 Forward Osmosis Draw solution in Diluted draw solution out Forward Osmosis System Feed water in Concentrated feed water out Bringing new technology to the water industry 5

6 Forward Osmosis Desalination Seawater or brackish water feed Reject from manipulated osmosis system Manipulated Osmosis System Diluted Osmotic Agent Concentrated Osmotic Agent Regeneration Membranes Product Water Bringing new technology to the water industry 6

7 Development 2006 Laboratory Work 2007 Trial Facility 2008 Production Facility 2009 Competitive Tendering Bringing new technology to the water industry 7

8 Laboratory Centre for Osmotic Research and Applications (CORA) at the University of Surrey Led by Professor Adel Sharif Membrane performance parameters Physical arrangements Analytical techniques Bringing new technology to the water industry 8

9 Trial Facility Located in Gibraltar Commissioned September 2008 Fabricated in UK Housed in a 20 ISO shipping container Located adjacent to an existing SWRO facility Bringing new technology to the water industry 9

10 Trial Facility Challenging location 50m inside a damp cave Open seawater intake Common pre-treatment with conventional SWRO plant (SDI 15, 3 4) Product water into public supply 1 May 2009 Independently tested TDS < 200 mg/l Boron < 0.6 mg/l Plant used for development activities Output doubled over test period 18m 3 /d Automatic operation, 24 hours a day Membranes never cleaned! Bringing new technology to the water industry 10

11 Product, mg/l B Boron Optimisation Without Boron Optimisation Initial Boron Optimisation Sun 01/11/2009 Sun 08/11/2009 Sun 15/11/2009 Sun 22/11/2009 Sun 29/11/2009 Bringing new technology to the water industry 11

12 Production Facility Al Khaluf Located in Al Khaluf, Oman Commissioned November 2009 Fabricated in UK Housed in a 40 High-cube ISO shipping container Design capacity 100m 3 /d Shares a common pre-treatment with a SWRO plant Bringing new technology to the water industry 12

13 Al Khaluf (100 m 3 /day) - Summary Fully operational since November 2009 water into public supply Common pre-treatment with conventional plant Shallow open sea water intake (39,000 mg/l) Single dual media filter (velocity m/h) SDI 5 typically 5 after cartridge filters (immeasurable elsewhere) FO System Cartridge filtration 10 micron nominal 35% - 38% recovery (design 30%) Antiscalant dosing Periodic low dose chlorination Membranes never chemically cleaned in over 24 months Bringing new technology to the water industry 13

14 Al Khaluf (100 m 3 /day) - Summary Operating personnel similar to RO MW trained local Omani s to operate Al Khaluf plant Product water meets requirements of Omani Standard No. 8/2006 with post-treatment, untreated product: Total dissolved solids < 200 mg/l Boron mg/l Visited by WDR in November 2010 and subsequently given a WDR Technology Rating of 8.9 the joint highest Bringing new technology to the water industry 14

15 Normalised Permeate Flow (m 3 /h) FO Normalised Flow (m3/h) Normalised Flow FO Plant Jan-2010 Feb-2010 Mar-2010 Apr-2010 May-2010 Jun-2010 Jul-2010 Aug-2010 Sep-2010 Oct-2010 Nov-2010 Dec Membranes Installed August 2009, 4.2 m 3 /h RO Plant New Membranes Installed Cleaning Activity on New Membranes % Decline in Output Over Just Five Months Jan-2010 Feb-2010 Mar-2010 Apr-2010 May-2010 Jun-2010 Jul-2010 Aug-2010 Sep-2010 Oct-2010 Nov-2010 Dec-2010 Bringing new technology to the water industry 15

16 Energy Consumption 25 kw Product 72 m 3 /d RO Feed 288 m 3 /d 25% Conversion 65 barg 8.5 kwh/m 3 Brine 216 m 3 /d 19 kw 2 kw MOD Feed 288 m 3 /d 35% Conversion 4 barg Product in OA 100 m 3 /d Brine 188 m 3 /d 47% Conversion 65 barg Product 100 m 3 /d 4.9 kwh/m 3 Bringing new technology to the water industry 16

17 Competitive Tendering Al Najdah In June 2011 Modern Water was awarded a contract to build a 200m 3 /d facility located in the same region as Al Khaluf Evaluation based on: Technical factors Economic factors (including through life cost) Fully commercial application of forward osmosis Incorporating fabrication of key process components in Oman Project currently under construction Commissioning in May 2012 Bringing new technology to the water industry 17

18 Forward Osmosis and Evaporative Cooling Bringing new technology to the water industry 18

19 Conventional Cooling Tower Drift Loss Evaporation Cooling Tower Make-up Heat Exchanger Chiller Plant Blowdown Recirculation Pumps Bringing new technology to the water industry 19

20 FO Cooling Tower System Evaporation Drift Loss Cooling Tower Recirculated Osmotic Agent Cooling System incorporating FO make-up (cooling water as osmotic agent) Heat Exchangers Concentrated Osmotic Agent Blowdown System Make-up via forward osmosis Manipulated Osmosis System Seawater or brackish water feed Reject from manipulated osmosis system Blowdown Bringing new technology to the water industry 20

21 FO Cooling Tower System Evaporation Drift Loss Cooling Tower Recirculated Osmotic Agent Cooling System incorporating FO make-up (cooling water as osmotic agent) Heat Exchangers Concentrated Osmotic Agent Blowdown System Make-up via forward osmosis Manipulated Osmosis System Seawater or brackish water feed Reject from manipulated osmosis system Blowdown Bringing new technology to the water industry 21

22 Pilot Evaporative Cooling System Demonstration / test plant housed in 20 container Extensively tested at Sohar Industrial Port, Oman Requires a source of raw water (seawater, brackish water, TSE), drain, power and heat load Membrane pre-treatment Multi-media pilot filter columns Air scour Backwash Flocculant dosing Antiscalant Packaged cooling tower Heat exchanger Membrane Support Systems Blowdown recovery system Bringing new technology to the water industry 22

23 Osmotic Agent / Cooling Water (1) Osmotic agent low cost, readily available and non toxic Osmotic agent concentration optimised for raw water feed to minimise losses Corrosivity 304 ss, 316 ss, Cu alloys little or no metal loss Carbon steel some metal loss, greatly reduced by corrosion inhibitor (phosphonates & carboxylic acid) Work ongoing Legionella (source CDCP) Bringing new technology to the water industry 23

24 Average counts of Lp (CFU/ml n=3) Osmotic Agent / Cooling Water (2) 1200 Biological testing Legionella killed in osmotic agent MIC 3.6 bar equivalent Pseudomonas not inhibited Blowdown system Loose membrane based Retains osmotic agent and chemical additives h 48 h 72 h Equivalent Osmotic Pressure (bar) Bringing new technology to the water industry 24

25 Evaporative Cooling FO Advantages Same platform technology as desalination application an ideal FO process Can utilise a wide range of feedwaters Significantly reduced power consumption compared with reverse osmosis (88% - 40%, typically 50%) Reduced CAPEX, compared to RO Extensive use of low cost plastic materials Low fouling propensity of forward osmosis process Cooling water additives are retained by the blowdown recovery system Can be retrofitted to existing installations Bringing new technology to the water industry 25

26 kwh/m3 Power Comparison Make up Water RO with ERT RO no ERT Manipulated Osmosis Manipulated Osmosis (OA recovery) 0 10,000 20,000 30,000 40,000 50,000 Feed Water TDS (mg/l) Assumptions Temperature 25ºC Maximum conversion on MO limited to 30% (very conservative) Pre-treatment requirements the same for MO and RO Conversion for RO, 80% - 41% depending on feed TDS Pump overall efficiency 70% Tower concentration ratio 5 Energy recovery efficiency 70% Bringing new technology to the water industry 26

27 Conclusions Robust process with proven resistance to membrane fouling Highly significant OPEX reductions Lower energy in particular for FO evaporative cooling process Numerous potential applications Desalination Waste water recovery Forward osmosis now a proven technology at industrial scale Bringing new technology to the water industry 27

28 Further Reading Cath T, Childress A, and Elimelech M Forward osmosis: Principles, applications, and recent developments Journal of Membrane Science, May Thompson A & Nicoll P Forward Osmosis Desalination: A Commercial Reality, Proceedings IDA World Congress, Perth, Western Australia, September Nicoll P, Thompson A, Bedford M Manipulated Osmosis Applied To Evaporative Cooling Make-Up Water Revolutionary Technology, Proceedings IDA World Congress, Perth, Western Australia, September Nicoll P, Forward Osmosis Applied to Desalination and Evaporative Cooling Make-up Water, International Water Conference, Orlando, USA, November Nicoll P, Thompson A, Gray V Forward Osmosis Applied to Evaporative Cooling Make-up Water, Cooling Technology Institute, February Bringing new technology to the water industry 28