Low energy production of fresh water from the sea by Forward Osmosis
Submitting Institution
University of SurreyUnit of Assessment
General EngineeringSummary Impact Type
TechnologicalResearch Subject Area(s)
Engineering: Chemical Engineering, Environmental Engineering, Materials Engineering
Summary of the impact
University of Surrey has a strong legacy of research into membrane
separation and osmosis,
culminating the commercialisation of Surrey's spin-out company Modern
Water plc. Modern Water
plc. was floated on AIM (London Stock Exchange) in June 2007 raising £30m
cash with a market
value of £70m.
The research itself is having direct impact via the operating
desalination plants in Gibraltar and
Oman producing high quality drinking water typically using 30% less energy
than conventional
desalination plants. In Oman, because of the poor quality of the feed
water the forward osmosis
process uses 42% less energy per litre of water produced when compared to
convential
equipment. The two plants currently operating in Oman serve 600 people in
Al-Khuluf and 800
people in Naghdah.
Underpinning research
The Food and Agriculture Organisation of the United Nations (FAO)
predicts that by 2025 1.8
billion people will be living in areas of absolute water scarcity, and
two-thirds of the world's
population will live in water stressed areas. 97.5% of the earth's water
is salt water.
Natural osmosis occurs when water passes from an area of low solute
concentration to an area of
high concentration, through a semi-permeable membrane, equalising the
level of concentration
between the two areas. By applying high levels of pressure to the process,
it is possible to force
this water movement to run in the opposite direction (Reverse Osmosis),
creating an area of high
solute concentration and an area of low solute concentration; when applied
to seawater, Reverse
Osmosis results in concentrated brine and drinking water. However, due to
the large number of
different chemical components in seawater, the instruments used during the
desalination process
suffer from significant corrosion, fouling and scaling problems, all of
which increase the cost of
operation by increasing energy and chemical consumption. Previously,
research into reducing the
problem has focused on mechanical solutions, for example the addition of
chemicals and frequent
filters replacement.
The Centre for Osmosis Research & Applications (CORA) at Surrey
University, which was founded
in 2003, adopted a different approach by researching the chemistry of
seawater, benefiting from a
£249,000 award by the Royal Society (Brain Mercer Award for Innovation)
and £115,000 from the
University SEED fund for the period 2005-2009. Funding has also come from
Modern Water plc,
£714,000, 2007-2012, and the Medicor Foundation, £120,000, 2012-2014. By
building on previous
research in membrane separation they found that by adding osmotic agents
to a formulated
solution, they could manipulate the osmotic barrier and allow only pure
water to move from
seawater creating a single ionic solution, which did not possess any of
the undesirable corrosive,
fouling and scaling properties of seawater. By avoiding the problem,
rather than just providing a
remedy, Surrey has developed a much more sustainable solution.
The Manipulated (Forward) Osmosis Technology process developed at Surrey
has a further
benefit of being highly efficient. The process begins with the
manipulation of the osmotic pressure
by adding an osmotic agent to a draw solution, thus allowing water to move
from the source,
seawater, leaving the salt behind. The resulting diluted solution then
undergoes a separation stage
using lower cost membrane to produce potable water, while the osmotic
agent is recycled for
reuse. Manipulated Osmosis provides a fouling resistance process
rather than a fouling resistance
membrane, achieved through the selection of osmotic agents that
have high solubility and do not
foul the membrane.
Research and field trials also confirmed that Manipulated (Forward)
Osmosis membranes
experience only reversible fouling which can be removed by backwashing, as
a result of operating
under low pressure with none of the compacting effect which normally
occurs at high pressure. The
Manipulated Osmosis process has been operating since 2009 in harsh
conditions in Oman serving
high quality water to the public, without the membranes requiring
cleaning. The research
undertaken at Surrey has focused on selecting suitable osmotic agents and
their regeneration
processes, which involves both fundamental and applied studies in physical
chemistry and process
engineering. Research into the modelling and optimisation of the osmosis
processes as well as
integrating them with renewable energy sources such as solar thermal has
also been undertaken.
The Manipulated Osmosis concept provides a platform technology for
applications in renewable
energy using the salinity gradient method for clean power production. The
Manipulated Osmosis
process has also been used in preparing the makeup water for cooling
towers and for secondary
oil recovery operations among other applications.
The research has also led to new IP to consolidate the background IP in
the area of osmotic power
and desalination, as well as having the potential to make the step-change
in these industries to
make them more sustainable and cost effective. The research activities
have also been extended
to cover other low carbon water treatment methods using electrical and
mechanical principles.
References to the research
1. Bowen, W.R., Sharif, A.O., "Prediction of optimum membrane
design: pore entrance shape and
surface potential", Colloids and Surfaces A — Physicochemical And
Engineering Aspects, Vol.
20, Issue: 1-3, pp 207-217, (2002). DOI: 10.1016/S0927-7757(01)01023-8
2. Bowen, W.R.; Filippov A.N.; Sharif, A.O., et al., "A model of
the interaction between a charged
particle and a pore in a charged membrane surface", Advances in Colloid
and Interface
Science, Vol. 81, Issue 1, pp 35-72, (1999). PII: S0001 - 868699.00004 -
4.
3. Sharif, A.O., Merdaw, A.A., Al-Bahadili, H., et al., "A New
Theoretical Approach to Estimate the
Specific Energy Consumption of Reverse Osmosis and other Pressure-Driven
Liquid-Phase
Membrane Processes", Desalination and Water Treatment, Vol. 3, Issue 1-3,
111-119 (2009).
DOI:10.5004/dwt.2009.295
4. Solvent Removal Process, Abdulsalam Al-Mayahi and Adel Sharif,
US Patent No: US
7,879,243; Date of Patent: Feb. 1, 2011; European Patent No. EP
1651570 Date of Issue: June
8, 2011.
5. Separation Process, Adel Sharif, European Patent number: EP
2,089142, Date of Issue: Sept.
9, 2010.
6. Merdaw, A.A, Sharif, A.O., and Derwish, G.A.W., "Mass transfer
in pressure-driven membrane
separation processes", Chemical Engineering Journal, Vol. 168, Issue 1, pp
215-228, (2011).
DOI: 10.1016/j.cej.2010.12.071
Details of the impact
Guildford-based Modern Water plc is a spin-out from the University of
Surrey specialising in
desalination and water treatment. Prof Adel Sharif developed the
desalination technology in the
University of Surrey and 5 patent families were filed between 2003 and
2006. The University, its
Seed Fund and a Brian Mercer award from the Royal Society, with others
(altogether £455,000)
funded early proof of concept and commercialisation, and external
investors including the IP Group
followed with £685,000. IP Group led the flotation on AIM (London Stock
Exchange) in 2007 raising
£30m in cash and with a market value of £70m with Surrey's desalination
technology being the
cornerstone of the flotation. Modern Water plc. has offices in the UK,
Middle East and China and
employs 52 staff, with a turnover of £3.7 million (2012). The company has
plans for further
expansion. The company provides successful desalination plants in
Gibraltar and Oman based on
Surrey's Manipulated/Forward Osmosis (FO) technology.
Gibraltar
The plant in Gibraltar produced its first drinking water in September
2008. Having operated over 3
years it has proved that FO has solved the well documented problems of
membrane fouling that
have existed for over 50 years. FO also scored the highest Coefficient of
Desalination Reality
(CDR) index of 8.9 of all new technologies in the sector in an independent
study by Global Water
Intelligence; (c).
Oman
A further plant opened in Oman in 2009 with a capacity of 100 m3/day,
operating in the harshest
conditions, with both very poor quality water intake and very high
salinity. Nonetheless it is
producing the highest quality desalinated water (<120 mg/l TDS) very
low in boron, with 42%
energy saving; (note; in less harsh conditions the FO process achieves
over 30% energy saving)
as well as other lower operating costs because of reduced chemical usage
and no membrane
cleaning or replacement (k).
In July 2011 Modern Water (l) won a competitive tender in Oman for
a third commercial FO plant
with a capacity of 200 m3/day. The plant was successfully
commissioned in September 2012 and
has since been providing the public with high quality water at a
reasonable cost. A recent BBC
Business News report on this latest Modern Water plant showed how happy
the local people are
with the quality of water; one of the villagers commented that they only
started to drink desalinated
water when the new FO plant opened whereas before they used to buy bottled
water. The plant
has a much lower environmental impact compared to conventional reverse
osmosis and thermal
desalination plants thereby improving on measures of sustainability.
In December 2012, a framework agreement was signed between Modern Water
and Hangzhou
Water, a leader in the desalination industry in China. Hangzhou Water has
a 60% share in the
Chinese desalination market. The framework agreement will allow both
organisations to jointly
identify and develop projects in China, including seawater desalination
plants and other water-related
opportunities.
In February 2013 Modern Water raised a further £10m from a share
placement, the company
maintains a research collaboration with the University of Surrey that has
produced a further six
desalination-related patents.
Professor Sharif and Modern Water were the winners of the
Energy/Environmental award of the
pan-European Enterprise ACES Award at the Royal Academy of Engineering in
Stockholm on 2
December 2008 for their innovative development of water purification using
desalination
technologies. The University of Surrey won the Queen's Anniversary Prize
for the water research
in which Prof. Sharif's work has played a major role.
Sources to corroborate the impact
a) Case study in "The economic benefits of chemistry research to
the UK" September 2010,
Oxford Economics
b) Christopher M. Snowden, Case study in `Technological innovation
in industry and the role
of the Royal Society', Notes & Records of the Royal Society,
2010.
c) Bankratz, T., "FO plant completes 1-year of operation", World
Desalination Report, 44, 15
November 2010.
d) Tim Blanchard, "Irrigation with seawater", New
Agriculturist, January 2012.
e) "Low-energy production of fresh water from sea water:
manipulated osmosis", Changing
Worlds — The Impact of University Research, House of Commons,
UK, October, 2010.
f) Kate Ravilious, "Add salt as required: the recipe for fresh
water", The New Scientists,
August 2010.
g) Peter Wrobel, "Fresh Thinking about Fresh Water", Science
Business, 12 March 2009
h) Prof Adel Sharif won European ACES Award, Water
Desalination Report, Vol. 44, Issue,
44, December 2008.
i) Phil Chamberlain, "The Stuff of Life", Institute of
Engineering and Technology
Knowledge Network, September 2008.
j) Williams, R., "Modern Water Aims to Clean Water by Osmosis", The
Independent
Newspaper, UK, 21 July 2008.
k) Public Authority for Electricity and Water, Sultanate of Oman.
Contact details provided.
l) CEO, Modern Water plc. Contact details provided.