Advanced Electrochemical Desalination & Biomimetic Membrane Technology

Solution Overview

Singapore's national water agency PUB is advancing electrochemical deionisation and biomimetic membrane technologies to dramatically reduce the energy intensity of seawater desalination.[1][2] Traditional desalination methods currently use about 3.5 kilowatt-hour (kWh) of electricity per cubic metre of water because high pressure is needed during the reverse osmosis process to push water through the polymeric membranes to filter out salts.[3] These innovative approaches draw inspiration from natural systems—mangrove trees and aquaporin proteins found in living organisms—that have evolved over millions of years to extract freshwater from seawater using negligible amounts of energy.[4][5]

Technical Components

The electrochemical deionisation (EDI) technology uses an electric field to remove dissolved salts from water, with the potential to be more energy-efficient than reverse osmosis, especially for water with low salinity.[6] Evoqua's low-pressure electrodialysis membrane technology enables water output quality to be tuned by power adjustments to minimize footprint and energy consumption.[7] Biomimetic membranes are inspired by nature and mimic the biological membranes in living cells to transport water, with the potential to be more permeable and require less energy.[8] PUB is working with the Nanyang Environment And Water Research Institute (Newri) at Nanyang Technological University (NTU) to develop membranes which are enhanced with aquaporin proteins or synthetic biomolecules that help to improve their permeability.[9] Aquaporins are proteins found in living organisms that enhance the transfer of water through a cell membrane, while synthetic biomolecules are a new innovation that replicate the effect of these aquaporins at a lower cost.[10] The principle of such applications is adopted from plant and animal life which have been extracting sea water for their survival evolved over millions of years, using negligible amounts of energy.[11] Mangrove trees, which grow in seawater, have the unique ability to filter out high concentrations of salt from the water they take in and can also transport water from their roots up to the rest of the plant with minimal resistance.[12] Developing membranes that mimic these abilities can save a significant amount of energy because lower operation pressure would be required to operate the desalting process.[13]

Implementation Details

Research and development of the electrochemical desalination technology began in 2008 when Evoqua, then Siemens Water Technologies, won a global competition for a three-year matching grant funded by the Singapore Environmental & Water Industry Programme Office.[14] Back in 2008, Siemens won a grant from Singapore's Environment & Water Industry Programme Office to build a demonstration unit that could desalinate seawater to drinking water quality, using just 1.5 kWh of power for each cubic metre of water that it produced.[15] Since December 2010, the Siemens demonstration unit has been treating 50 m³ of seawater per day at a PUB facility in Singapore.[16] The unit is successfully producing drinking water from seawater using approximately 50% of the energy required by the most efficient desalination technology available today.[17] EDI desalination modules have been used at a demonstration plant in Tuas since March and are able to treat 3,800 cubic metres of sea water per day.[18] The rate of energy consumption of the Tuas EDI demonstration plant is 2.4kwh per cubic metre of water treated, according to PUB's assistant chief executive Harry Seah.[19] PUB's assistant chief executive Harry Seah hopes to reduce the rate of energy consumption of desalination at the Tuas demonstration plant to 1.8kwh per cubic metre of sea water by next year, down from 2.4kwh per cubic metre.[20] PUB said it aims to scale up its operations at the Tuas demonstration plant to 10,000 cubic metres of sea water per day by next year.[21]

Singapore's national water agency PUB and Evoqua Water Technologies agreed to a memorandum of understanding (MOU) to further develop electrochemical desalination technology that aims to improve energy and cost efficiencies in seawater desalination.[22] Evoqua has been presently engaged in a demonstration with PUB of initial feasibility of advanced electrochemical desalination technology.[23] PUB and Evoqua will explore the design, construction, installation and evaluation of a system comprising Evoqua E-Desal equipment to produce drinking water from seawater with an eventual capacity of 1 million gallons per day (mgd).[24] PUB and Evoqua will commission the initial phase of the demo project by December 31, 2014.[25] The production costs of the EDI technology have been reduced to a fraction of its original cost from half a million dollars to about $40,000, according to Dr Qiao Xiangyi, Evoqua's research and development manager.[26]

PUB is trialling new technology including ceramic membranes and biomimetic membranes at PUB's research and development plant in Tuas to see if these are more durable, cost-efficient and energy-saving compared with the usual polymeric membranes used in desalination.[27] Biomimetic membranes developed by Newri are able to achieve at least a 50 per cent enhancement in water permeability compared with commercial ones for seawater desalination.[28] A 10 m³/day pilot to scale up Newri's aquaporin-based biomimetic membranes is currently being constructed at the Tuas R&D Facility and will be ready in Sept this year, with the pilot lasting for six months.[29] A new desalination integrated validation plant will be located in Pasir Ris by next year and will integrate, configure and optimise technologies including the ceramic and biomimetic membranes to validate if lower energy consumption and better performance can be achieved for desalination.[30]

Biomimetic membranes have also been used in the production of Newater and are currently being piloted at the Ulu Pandan Newater plant at a capacity of 14 m³/day.[31] Aquaporin completed the Living Lab Project to develop the world's first biomimetic low-energy Aquaporin Inside® CLEAR membrane at demonstration scale, with membranes installed at the Kranji NEWater Factory (KNF), operated by PUB, Singapore's National Water Agency.[32] The Aquaporin CLEAR membranes will continue to be operated and monitored at KNF, while delivering NEWater standard permeate into PUB's distribution network.[33] The Environment and Water Industry Programme Office (EWI) is investing $470million from Singapore's National Research Foundation in water R&D.[34]

Benefits and Impacts

In 2009, PUB and Evoqua Water had shown using proof-of-concept EDI models that they could achieve an energy consumption rate of 1.65kwh per cubic metre of sea water.[35] After 12 months of continuous operation benchmarked against parallel concurrently operated trains with other commercial membranes, the Aquaporin Inside® CLEAR biomimetic membranes achieved up to 20% energy savings for the energy-intensive reverse osmosis treatment stage, while consistently meeting the stringent water quality standards of NEWater.[36] Following the successful 12-month demonstration, Aquaporin will work with PUB to explore further collaboration opportunities to expand the use of low-energy membranes to other NEWater factories.[37] PUB aims to reduce the system-level energy consumption of desalination to less than 2kWh per cubic metre.[38] Singapore is hoping to reduce current energy requirements for membrane desalination from 3.5kWh down to 0.8kWh/m³.[39] With further breakthroughs in research and development, the long-term target set by Singapore is to reduce desalination energy consumption to 0.8kWh/m³.[40]

Climate Adaptation Relevance

Currently, up to 30 per cent of Singapore's water needs is desalinated by reverse osmosis, a process which uses about 3.5 kilowatt hours (kwh) to produce 1 cubic metre of desalinated water.[41] PUB is part of Singapore's GreenGov.SG movement that aims for the public sector to achieve net zero emissions around 2045, which is earlier than the national target of 2050.[42] PUB, Singapore's National Water Agency, is leading research and development for the water sector in Singapore to improve energy efficiency and reduce the carbon footprint of water treatment processes.[43]

Business Analysis

Singapore is exploring the use of ultra-permeable membranes, blue energy (e.g. pressure-retarded osmosis) and ceramic membranes to reduce energy consumption in the desalination process.[44] One of the technologies which PUB is looking into to achieve that target is the use of Biomimetic membranes/Biomimicry in desalination plants.[45] The Environment and Water Industry Programme Office (EWI), which spearheads the growth of Singapore's water industry, is investing $470million from Singapore's National Research Foundation in water R&D to promote research and development in this field.[46] The production costs of the EDI technology have been reduced to a fraction of its original cost from half a million dollars to about $40,000, demonstrating significant progress in commercial viability.[47]

[1]: PUB aims to reduce the system-level energy consumption of desalination to less than 2kWh per cubic m. [2]: Back in 2008, Siemens won a grant from Singapore's Environment & Water Industry Programme Office to build a demonstration unit that could desalinate seawater to drinking water quality, using just 1.5 kWh of power for each cubic metre of water that it produced. [3]: Traditional desalination methods currently use about 3.5 kilowatt-hour (kWh) of electricity per cubic m of water because high pressure is needed during the reverse osmosis process to push water through the polymeric membranes to filter out salts. [4]: Mangrove trees have the unique ability to filter out high concentrations of salt from the water they take in and can also transport water from their roots up to the rest of the plant with minimal resistance. [5]: The principle of such applications is adopted from plant and animal life which have been extracting sea water for their survival evolved over millions of years, using negligible amounts of energy. [6]: Electrochemical deionisation has the potential to be more energy-efficient than reverse osmosis, especially for water with low salinity. [7]: Evoqua's low-pressure electrodialysis membrane technology enables water output quality to be tuned by power adjustments to minimize footprint and energy consumption. [8]: Biomimetic membranes have the potential to be more permeable and require less energy for water treatment. [9]: PUB is working with the Nanyang Environment And Water Research Institute (Newri) at Nanyang Technological University (NTU) to develop membranes which are enhanced with aquaporin proteins or synthetic biomolecules that help to improve their permeability. [10]: Aquaporins are proteins found in living organisms that enhance the transfer of water through a cell membrane, while synthetic biomolecules are a new innovation that replicate the effect of these aquaporins at a lower cost. [11]: The principle of such applications is adopted from plant and animal life which have been extracting sea water for their survival evolved over millions of years, using negligible amounts of energy. [12]: Mangrove trees, which grow in seawater, have the unique ability to filter out high concentrations of salt from the water they take in. They can also transport water from their roots up to the rest of the plant with minimal resistance. [13]: Developing membranes that mimic mangrove abilities can save a significant amount of energy because lower operation pressure would be required to operate the desalting process. [14]: Research and development of the electrochemical desalination technology began in 2008 when Evoqua, then Siemens Water Technologies, won a global competition for a three-year matching grant funded by the Singapore Environmental & Water Industry Programme Office. [15]: Back in 2008, Siemens won a grant from Singapore's Environment & Water Industry Programme Office to build a demonstration unit that could desalinate seawater to drinking water quality, using just 1.5 kWh of power for each cubic metre of water that it produced. [16]: Since December 2010, the Siemens demonstration unit has been treating 50 m3 of seawater per day at a PUB facility in Singapore. [17]: The unit is successfully producing drinking water from seawater using approximately 50% of the energy required by the most efficient desalination technology available today. [18]: EDI desalination modules have been used at a demonstration plant in Tuas since March and are able to treat 3,800 cubic m of sea water per day. [19]: The rate of energy consumption of the Tuas EDI demonstration plant is 2.4kwh per cubic m of water treated, according to PUB's assistant chief executive Harry Seah. [20]: PUB's assistant chief executive Harry Seah hopes to reduce the rate of energy consumption of desalination at the Tuas demonstration plant to 1.8kwh per cubic m of sea water by next year, down from 2.4kwh per cubic m. [21]: PUB said it aims to scale up its operations at the Tuas demonstration plant to 10,000 cubic m of sea water per day by next year. [22]: Singapore's national water agency PUB and Evoqua Water Technologies agreed to a memorandum of understanding (MOU) to further develop electrochemical desalination technology that aims to improve energy and cost efficiencies in seawater desalination. [23]: Evoqua has been presently engaged in a demonstration with PUB of initial feasibility of advanced electrochemical desalination technology. [24]: PUB and Evoqua will explore the design, construction, installation and evaluation of a system comprising Evoqua E-Desal equipment to produce drinking water from seawater with an eventual capacity of 1 million gallons per day (mgd). [25]: PUB and Evoqua will commission the initial phase of the demo project by Dec. 31, 2014. [26]: The production costs of the EDI technology have been reduced to a fraction of its original cost from half a million dollars to about $40,000, according to Dr Qiao Xiangyi, Evoqua's research and development manager. [27]: PUB is trialling new technology including ceramic membranes and biomimetic membranes at PUB's research and development plant in Tuas to see if these are more durable, cost-efficient and energy-saving compared with the usual polymeric membranes used in desalination. [28]: Biomimetic membranes developed by Newri are able to achieve at least a 50 per cent enhancement in water permeability compared with commercial ones for seawater desalination. [29]: A 10 m3/day pilot to scale up Newri's aquaporin-based biomimetic membranes is currently being constructed at the Tuas R&D Facility and will be ready in Sept this year, with the pilot lasting for six months. [30]: A new desalination integrated validation plant will be located in Pasir Ris by next year and will integrate, configure and optimise technologies including the ceramic and biomimetic membranes to validate if lower energy consumption and better performance can be achieved for desalination. [31]: Biomimetic membranes have also been used in the production of Newater and are currently being piloted at the Ulu Pandan Newater plant at a capacity of 14 m3/day. [32]: Aquaporin completed the Living Lab Project to develop the world's first biomimetic low-energy Aquaporin Inside® CLEAR membrane at demonstration scale, with membranes installed at the Kranji NEWater Factory (KNF), operated by PUB, Singapore's National Water Agency. [33]: The Aquaporin CLEAR membranes will continue to be operated and monitored at KNF, while delivering NEWater standard permeate into PUB's distribution network. [34]: The Environment and Water Industry Programme Office (EWI) is investing $470million from Singapore's National Research Foundation in water R&D. [35]: In 2009, PUB and Evoqua Water had shown using proof-of-concept EDI models that they could achieve an energy consumption rate of 1.65kwh per cubic m of sea water. [36]: After 12 months of continuous operation benchmarked against parallel concurrently operated trains with other commercial membranes, the Aquaporin Inside® CLEAR biomimetic membranes achieved up to 20% energy savings for the energy-intensive reverse osmosis treatment stage, while consistently meeting the stringent water quality standards of NEWater. [37]: Following the successful 12-month demonstration, Aquaporin will work with PUB to explore further collaboration opportunities to expand the use of low-energy membranes to other NEWater factories. [38]: PUB aims to reduce the system-level energy consumption of desalination to less than 2kWh per cubic m. [39]: Singapore is hoping to reduce current energy requirements for membrane desalination from 3.5kWh down to 0.8kWh/m3. [40]: With further breakthroughs in research and development, the long-term target set by Singapore is to reduce desalination energy consumption to 0.8kWh/m3. [41]: Currently, up to 30 per cent of Singapore's water needs is desalinated by reverse osmosis, a process which uses about 3.5 kilowatt hours (kwh) to produce 1 cubic m of desalinated water. [42]: PUB is part of Singapore's GreenGov.SG movement that aims for the public sector to achieve net zero emissions around 2045, which is earlier than the national target of 2050. [43]: PUB, Singapore's National Water Agency, is leading research and development for the water sector in Singapore to improve energy efficiency and reduce the carbon footprint of water treatment processes. [44]: Singapore is exploring the use of ultra-permeable membranes, blue energy (e.g. pressure-retarded osmosis) and ceramic membranes to reduce energy consumption in the desalination process. [45]: One of the technologies which PUB is looking into to achieve that target is the use of Biomimetic membranes/Biomimicry in desalination plants. [46]: The Environment and Water Industry Programme Office (EWI) is investing $470million from Singapore's National Research Foundation in water R&D. [47]: The production costs of the EDI technology have been reduced to a fraction of its original cost from half a million dollars to about $40,000, according to Dr Qiao Xiangyi, Evoqua's research and development manager.