Más contenido relacionado
La actualidad más candente (20)
Similar a Desalination_Taking_Ocean_Water_to_Taps (20)
Desalination_Taking_Ocean_Water_to_Taps
- 1. © 2014 QuEST Global Services
Desalination:
Taking Ocean Water to Taps
Uma Upadhyay
QuEST Global
- 2. © 2014, QuEST Global Services
Contents
1Introduction
Increasing Global Demand for Desalination Plants 1-2
Desalination Technology Evolution 2
Reverse Osmosis: Taking care of your Desalination needs 2-3
Seawater RO Membrane Technology Advancement 3
Use of High Productivity Elements 3
Use of High Efficiency Pressure Pump 3
Use of Energy Recovery Device 4
Energy Consumption SWRO 4
Challenges in Desalination Plants 4
Future Technology Advances 4
Key Takeaways 4-5
QuEST in Water Domain 5-6
Case Study 6
References 6
Author Profile 7
- 3. © 2014, QuEST Global Services1
Desalination
Introduction
Fresh water reserves are becoming hardly usable due to extreme urbanization and industrialization. Groundwater reserves are turning
saline due to seawater intrusion. Water demand for agriculture is also rising due to increased population. Stricter norms and regulations
restrict industries from using freshwater sources for their industrial needs, thereby giving them no other option but to look for alternate
water sources.
According to India Water Review (2012), it is estimated that currently 1.1 billion people across the world do not have access to safe
drinking water and more than twice that number are without adequate sanitation. It is estimated that by the year 2025, more than 60%
of the world population living in 88 countries is expected to face serious water shortage. Severe water shortages are mainly due to
explosive
population growth, extensive changes in human lifestyle, increased industrial activities and pollution. The use of unhygienic quality of
water is the root cause for 80%-90% of all diseases in developing countries16
.
Having a reliable source of fresh water for the future is of high priority. The need of reliable source of fresh water prompts for a
technology that extracts fresh water by removing saline (salt) from bodies of salt water. Desalination is being increasingly realized as
the answer to the water crisis of the 21st century.
With this whitepaper, QuEST Global aims to provide clear insights on the desalination technology trends, market, energy consumption,
benefits and challenges of the desalination process.
Increasing Global Demand for Desalination Plants
The ever exploding world population, which is expected to reach 7.52 billion by 2020, up from 6.85 billion in 2010, is depleting a limited
fresh water supply with agricultural demands and urbanization leading to more water consumption per person across the globe.
Industrialization is spreading advanced water extraction technology, which is quickly diminishing water resources.
At present, desalination is adapted by countries having a greater need for fresh water, have enough money to fund it, and possess the
amount of energy required to produce it.
The global desalination market has been forecasted to hit a market value of $52.4 billion by 2020, a monumental growth of 320.3% from
$12.5 billion in 2010, and $18.37 billion in 20123
.
The Middle East tops the list of desalinated water usage, due to severe water scarcity. Extensively large desalination plants are present
in Saudi Arabia, the United Arab Emirates, and Israel. Countries such as the United States, Spain, Algeria, China, India, and Australia
are large producers of desalinated water. Desalination is expected to grow increasingly, particularly in the United States, Libya, China,
and India. The below graph represents the desalination market forecast among countries where there is severe scarcity of water.
Figure 1: Desalination Market Forecast, June 2011, GWI12
- 4. © 2014, QuEST Global Services2
Desalination
Reverse Osmosis
The below graph suggests the increased adaption of reverse osmosis process for desalination with increase in the capacity of
desalination plants. It also indicates the increase in the usage of RO with respect to time.
60.2%
27.1%
0.8%
3.6%
0.3%
8.0%
RO MSF MED ED Hybrid EDI
Figure 2: Usage of different technologies in Desalination; Source: Desalination Technology Market (IRENA, 20122
)
The above forecast (Figure 1) projects the expected increase in the capacity of new desalination plants. The forecast also shows the
capacity of desalination plants from the year 2007-2011. This is an indication of the total capacity of desalination plants.
According to the latest report by GWI, industrial desalination and water reuse technologies market is expected to approach $12bn by
20254
. A new report by Pike Research estimates that the global installed capacity of desalination projects will grow by about 55 million
cubic meters per day (m3
/d) during the period between 2010 and 2015. About 54 percent of that growth will occur in the Middle East and
North Africa5
.
Desalination Technology Evolution
Desalination is a process that removes dissolved salts and other minerals from seawater or salty water bodies to provide clean drinking
water. The main feature of desalination is that it delivers high quality drinking water for consumption, and industrial purposes even
during drought. It also acts as an alternative source of water that could make overall supply more diverse and less vulnerable to
interruption. It can be said without any exaggeration that one of the prominent solutions to water scarcity is Desalination.
Desalination started to emerge as a large scale process during the sixties. Various desalination technologies have been developed over
the years based on thermal distillation, membrane separation, freezing, electro-dialysis, to mention a few. Commercially, two most
important technologies are based on the Multi Stage Flash (MSF) and Reverse Osmosis (RO processes).
Thermal distillation is the oldest form of desalination and was first used to produce drinking water for large urban communities in the
early 1950s. Thermal processes accounted for slightly more than 70% of the global desalted water capacity in operation by the year
2000, and are used in majority of the desalination plants with a capacity of more than 100 Million Litre per day (ML/d). Membrane
processes using Reverse Osmosis (RO) membranes were first used in the mid 1960s on small desalination systems (less than 10
ML/d).
However, due to continuous improvement in RO technology, more than 70% of the desalination plants installed since 2000, including
major facilities with capacities in excess of 100 ML/d, used RO1
.
Reverse Osmosis: Taking care of your Desalination needs
Presently, Reverse Osmosis is the most popular desalination process in the world. The water is forced through membranes at high
pressure. These membranes remove dissolved salts and other microscopic particles present in the water.
Figure 2 represents the usage of different technologies in desalination:
- 5. Figure 3 shows the GWI’s latest desalination forecast that following a dip in 2012, the volume of new reverse osmosis capacity
contracted each year is set to grow to 5.2 million m3
/d in 2013, rising to 10.8 million m3
/d in 2016.
According to a report by TechSci Research, the Indian water desalination market is expected to register a compound annual growth rate
(CAGR) of 22% in the next five years. The estimated market size for India’s water desalination industry is set to reach $0.63 billion by
20147
. The increased governmental support and rising demand for fresh water leads to the deployment of more desalination plants
across India. The desalination market in India has witnessed phenomenal growth in last three years and has now emerged as a cost-ef-
fective solution to the need to provide water. The Indian desalination water market is growing at an annual rate of 30 per cent over a
period of five years from 2013 to 2018, according to MSN India, as of April 20138
. The new desalination water facility at Nemmeli (Tamil
Nadu, India) is a part of civic drinking water improvements and road infrastructure upgrades valued at about $317 million9
.
Minjur desalination plant in the state of Tamil Nadu houses the largest desalination plant in India, with a capacity of 100,000 m³/day
(100mld). This desalination plant is capable of serving potable water using Reverse Osmosis (RO) technology and serves an estimated
population of 500,000+ in Chennai, India. The second largest plant in India is located at Jamnagar, Gujarat, with a capacity of 96,000
m³/day10
. The state governments of Andhra Pradesh and Orissa are also debating the prospects of setting up desalination plant. The
state of Gujarat seems to be further along the way towards having its own desalination units. TechSci said, it sees India acting as a
growth engine for the global water desalination industry11
.
Seawater RO Membrane Technology Advancement
Use of High Productivity Elements
The main factor that has contributed to the dramatic change in cost reduction of sea water desalination is the advancement of the Sea
Water Reverse Osmosis (SWRO) membrane technology. Presently high-productivity membrane elements are designed with several
features that can yield more fresh water per membrane element than at any time in the recent history of this technology. For example,
early elements (1970s) were about 4 inches in diameter that displayed flow rates approaching 250 L/h and sodium chloride rejection of
about 98.5 percent as compared to one of today’s 16 inch diameter elements capable of delivering 15-30 times more permeate
(4000-8000 L/h) with 5 to 8 times less salt passage (hence a rejection rate of 99.7 percent or higher) 13
. Although 8 inch SWRO
membrane elements are still the ‘standard’ size most widely used in full-scale applications, larger 16 inch and 18 inch size SWRO
membrane elements have become commercially available.
In the second half of the 1990s, the typical 8 inch SWRO membrane element had a standard productivity of 5,000 to 6,000 gallons per
day (gpd) at a salt rejection of 99.6%. In 2003, several membrane manufacturers introduced high-productivity sea water membrane
elements which are capable of producing 7,500 gpd at a salt rejection of 99.75%. Just one year later, even higher productivity (9,000
gpd at 99.7% rejection) sea water membrane elements were released in the market. Over the past four years SWRO membrane
elements combining a productivity of 10,000 to 12,000 gpd with high salinity rejection have become commercially available and are now
gaining wider project implementation. The newest membrane elements provide flexibility and choice and allow users to trade
productivity and pressure/power costs. The same water product quality goals can be achieved in one of the two general approaches:
(1) reducing the system footprint/ construction costs by designing the system at higher productivity, and (2) reducing the system’s
overall power demand by using more membrane elements, designing the system at lower flux and recovery, and taking advantage of
new energy recovery technologies, which further minimize energy use if the system is operated at lower (35% to 45%) recoveries14
.
Innovative hybrid membrane configuration combining SWRO elements of different productivity and rejection within the same vessel,
which are sequenced to optimize the use of energy introduced with the feed water to the desalination vessels, is also finding wider
implementation.
Figure 3: Scaling up the membrane challenge,6
Global Water Intelligence, October 2012.
© 2014, QuEST Global Services3
Desalination
- 6. © 2014, QuEST Global Services4
Desalination
Use of High Efficiency Pressure Pump
Pumps are responsible for more than 40% of total energy costs at a desalination facility. Energy efficiency advances in a type of pump
that is useful for smaller applications (called a positive displacement pump) have made desalination more cost-effective for some
applications and locations and less sensitive to electricity price increases17
.
An approach for reducing total RO system energy use, which is widely applied throughout the desalination industry is to incorporate
larger, higher efficiency centrifugal pumps that serve multiple RO trains. This trend stems from the fact that the efficiency of multistage
centrifugal pumps increases with their size (pumping capacity). However, if the RO system configuration is such that a single high
pressure pump is designed to service two RO trains of the same size, the efficiency of the high pressure pumps could be increased by
up to 85%14
.
Use of Energy Recovery Device
With the increasing capacities of SWRO System, it is necessary to use the Brine/Concentrated Stream as an opportunity to reduce the
energy consumption by using this brine to pressurize the incoming raw seawater to the system. Advances in Energy Recovery
Technology and equipment show a reduction of 80% of the energy use for water production over the last 20 years.
Few years ago, majority of the existing sea water desalination plants used Pelton wheel based technology to recover energy from the
SWRO concentrate, but today the pressure exchanger based energy recovery systems dominate in most desalination facility designs.
The weak point of Pelton technology is the formation of a foamy stream that can only be evacuated by gravity, or re-pumped after it has
settled.
Pressure Exchanger device, can reduce the amount of energy required to desalinate sea water by up to 60% compared to a process
with no energy recovery. This savings can result in more economical
production of drinking water and a reduced carbon footprint.
Energy Consumption SWRO
Towards the end of 1970s, SWRO Plant consumed upto 20kWh/m3, but due to advancement in membrane element and energy
recovery devices, the energy consumption has been reduced drastically. Excellent specific energy consumption as low as 1.8-2.2
kWh/m3 can be achieved in new SWRO Plants18
.
Challenges in Desalination Plants
• It is very costly to build and operate desalination plants. Once opera tional, plants require huge amounts of energy. Energy costs
account for one-third to one-half of the total cost of producing desalinated water. Because energy is such a large portion of the total
cost, the cost is also greatly affected by changes in the price of energy.
• Environmental impacts are another disadvantage to desalination plants. Disposal of the salt removed from the water is a major
issue. This discharge, known as brine, can change the salinity and lower the amount of oxygen in the water at the disposal site,
stressing or killing animals not used to the higher levels of salt. In addition, the desalination process uses and produces numerous
chemicals including chlorine, carbon dioxide, hydrochloric acid and anti-sca lents which can be harmful in high concentrations.
Future Technology Advances
Key areas of development of RO membrane technology are associated with the increase in the productivity of the membrane elements,
their resistance to fouling by the contaminants contained in the source water, and their durability and longevity. The quest for increased
productivity of RO membrane elements has taken two directions: (1) development of larger diameter membrane elements and (2)
incremental improvements in the SWRO membrane structure, chemistry, spacer size, and configuration, which can allow more flow to
be produced by a square inch of RO membrane area with reduced downtime for membrane cleaning. For future advancement of the
Desalination needs one can look up the following areas:
• Focus on Fundamental Understanding of Factors Limiting Desalination Plant Performance
• Advancement of Pre-treatment, RO Desalination and Concentrate Disposal Technologies
• Development and Demonstration of New Non- RO/Hybrid Technologies
• Concentrate Minimization Research
• Use of Renewable Power for Desalination
Key Takeaways
The future of desalination lies in an energy-efficient approach of converting sea-water into fresh water. This approach will make
desalination economically feasible. There has been a sudden increase in the number of scientists and engineers involved in the
research and development of desalination processes.
Desalination technology has witnessed a lot of public and private investments to develop and optimize the plant designs and operations.
Desalination is successful in providing water supplies in the dry regions of the globe. Despite desalination process costs becoming
- 7. © 2014, QuEST Global Services5
Desalination
economically viable, the total cost of desalination, including planning and management remain relatively high and also as against the
total costs of other alternatives.
Yet the increasing demand for desalination remains undisputed. It is very imminent to evaluate the current and future financial and
economic circumstances that are likely to affect the technology as it advances.
QuEST in Water Domain
QuEST Global being one of the leading engineering outsourcing organisation has been involved in various verticals and domain, has
the capability to design the water treatment plants based on various advanced technologies like desalination, membrane bio-reactor,
and zero-liquid discharge. QuEST Global has a pool of trained engineers with domain knowledge and good project engineering as well
as technical skills. The team has expertise in managing and executing projects globally, driving projects through mature processes and
ensuring quality deliverables that reduce work.
QuEST engineering team has engineered several desalination treatment plants – RO/UF, EDI. QuEST is involved in complete
engineering lifecycle of desalination plants, which includes process engineering, mechanical piping engineering, electrical-
instrumentation engineering, control engineering and programmable logic controller (PLC) automation. QuEST is involved in the GA and
P&ID preparation, Detail Engineering, Equipments Sizing, Instruments and Valves selection, ordering of the Equipments and BOM
preparation.
QuEST aims to provide better engineered solutions by thoroughly evaluating the economic desirability, cost of alternatives, and
assessing the environmental conditions. QuEST differentiators are as follow-
• QuEST has client specific secured network, infrastructure & delivery centers.
• QuEST has the flexible model working environment – onshore, onsite, offshore & local-global.
• QuEST is capable of managing the workload effectively with 100% focus on quality.
• 100% focus on product development & support services
• Capable capacity & cost optimization through Local-Global model.
• Range of flexible operating business models.
• Ability to build, manage & work with global engineering teams.
• 15 years of engineering experience with highly mature off-shoring processes.
• Passionate, agile, flexible and responsive team.
• Using QuEST team overall project cost can come down around 25-30%.
With proven expertise in engineering services, it possesses the capability to offer superior engineering services in water domain.
QuEST water team has 23% mechanical engineers and 36% Engineers are working in Piping/Drafting. QuEST Team capability is
shown below in Fig. 4, Fig. 5 and Fig. 6 in terms of experience, Discipline and Education.
Figure 4: QuEST Water Team Experience Distribution
- 8. © 2014, QuEST Global Services6
Desalination
Figure 5: QuEST Water Team distribution based on discipline
Case Study
QuEST has completed designs to build RO, EDI, UF, MBR based water Treatment plants. A typical engagement with QuEST begins
with receiving Proposal/ Pre Bid Engineering Document, Project Specifications as input from the customer. QuEST studies the primary
inputs and generate secondary inputs. Mechanical Engineers are involved in the sizing calculations and selection of equipments
pumps, blowers, compressors, valve and instruments. Drafting experts are involved in the preparation of Conceptual Piping Layout,
MTO Preparation, Modeling and interference check. Electrical Engineers are involved in IO counting & listing and Control Team is
involved in the programming and customizing of the PLC logic as per Control Documents; SCADA as per P&IDs for monitoring the plant
units by validation screen using RSview32 for the simulation purpose.
QuEST delivers the P&ID, GAD, Isometrics, Piping Layout, Fabrication Drawings, Bill of Material (BOM), Datasheets, Instruments List,
Valve List and Equipment List, Single Line Diagram, Electrical Layout, Tested PLC Logic, SCADA backup, HMI and PLC Testing reports,
QMS Checklists, Mechanical & Electrical Production Package to Factory for Fabrication and Assembly.
QuEST Mechanical /Drafting Teams are using softwares like SAP, Bentley PSDS-XM, Microstation. Electrical team is working on
Promis-E, AutoCAD software and Control Team is working on Allen Bradley PLC Software & Hardware for PLC automation.
References
1) Emerging trends in desalination: A review UNESCO Centre for Membrane Science and Technology University of New South
Wales Waterlines Report S¬¬¬¬eries No 9, October 2008.
2) http://www.irena.org/DocumentDownloads/Publications/IRE NA-ETSAP%20Tech%20Brief%20I12%20Water-Desalination.pdf
3) http://www.companiesandmarkets.com/News/Energy-and-Utilities/Global-desalination-market-driven-by-the-water- crisis-facing
-the-human-race-over-the-next-century/NI5952
4) http://www.globalwaterintel.com/industrial-desalination- water-reuse-technologies-market-approach-12bn-2025/
5) http://e360.yale.edu/digest/market_for_desalination_plants_expected_to_grow_by_87_billion_by_2016/2730/
6) http://www.globalwaterintel.com/archive/13/10/market-profile/scaling-membrane-challenge.html
7) http://www.indiawaterreview.in/Story/News/india-desalination-market-to-grow-at-22-cagr-till-2017/542/1
8) http://news.in.msn.com/business/%E2%80%98water-desalination-has-big-potential-in-india%E2%80%99
9) http://www.bloomberg.com/news/2013-04-16/chennai-gets-third-water-desalination-plant-times-of-india-says.html
10) http://www.water-technology.net/projects/minjurdesalination/
11) http://www.livemint.com/Politics/FvpXSl7v5JClJIPjy DLejO/The-desalination-dilemma.html
12) http://www.globalwaterintel.com/archive/12/6/analysis/chart-month-top-ten-desalination-markets-expected- contracted-
capacity.html
13) Engineering Aspects of Reverse Osmosis Module Design, J. Johnson & M. Busch, Research Specialist, Research and
Development, Dow Water & Process Solutions, 2009.
14) Sea Water Desalination: Current Trend and Challenges, http://www.iwawaterwiki.org/xwiki/bin/view/Articles/Overvie wofSeawater
DesalinationStatusandChallenges
15) www.frost.com/prod/servlet/cio/176353336
16) http://www.researchandmarkets.com/reports/2065693/india_water_desalination_plants_market_forecast.pdf
17) Desalination and Membrane Technologies: Federal Research and Adoption Issues,Nicole T. Carter, 2013
18) Current trends and future prospects in the design of seawater reverse osmosis desalination technology, B.Peñate & L.
García-Rodrígue, 2012
Figure 6: QuEST Water Team distribution based on education
- 9. © 2014, QuEST Global Services7
Desalination
Author Profile
Uma Upadhyay has around six years of experience in the field of Water and Wastewater. Her professional experience consists
of hydraulic designs and estimations of Sewage Treatment Plants of various capacities based on different technologies like Activated
Sludge Process, Extended Aeration, Facultative Aerated Lagoon, Reed Bed Systems, and Waste Stabilization Ponds. She has also
worked on Design of Pumping Stations, Sewerage Networks and Water Supply Networks.
She holds a Bachelor’s degree in Chemical Engineering from Uttar Pradesh Technical University, Lucknow, India and a Master’s Degree
in Environmental Engineering from Indian Institute of Technology, Roorkee, India.
She was awarded by Kathpalia Award for the best dissertation during her Masters degree program. She has published a research paper
titled, “Anaerbobic Degradation of Benzoate: Batch Study” in the Journal Bioresource Technology. This is available on Science
Direct.com.
In her two years at QuEST Global so far, she has worked on Detail Engineering projects related to Reverse Osmosis, Ultra Filtration and
Membrane Bio Reactor technologies.
- 10. QuEST GLOBAL SERVICES PTE LTD
7, Temasek Boulevard,
#09-04 Suntec Tower One,
Singapore 038987
Tel: +65 6272 3310
Fax: +65 6272 4495
http://engineering.quest-global.com
About QuEST Global
QuEST Global's commitment to quality and distinguished record in Engineering
Consulting Services and Manufacturing has enabled it to establish a leadership position
in most of its service offerings. With a "best-in-class" global leadership team, QuEST
Global is recognized as one of the largest pure-play engineering services player,
providing integrated product development and build solutions across the engineering
services value chain.
QuEST Global believes in 100% focus on Product Development and Engineering Design
Services that help organizations to cut product development costs, shorten lead times,
extend capacity and maximize engineering resources availability - by providing them
support across the complete product life cycle from design and modeling through
analysis, prototyping, automation, data documentation, instrumentation and controls,
embedded systems development, manufacturing support, vendor management and
in-house precision machining.
Pioneers in offshore product development, QuEST Global drives unified delivery through
its unique local-global model, by combining physical proximity to customer and delivery
from low cost locations across diversified verticals. Some of its clients are blue chip
companies like GE, United Technologies, Rolls-Royce and Toshiba.
QuEST Global employs over 4,300 professionals and has global delivery centers across
Australia, France, Germany, India, Italy, Japan, Singapore, Spain, UK & US.
© 2014, QuEST Global Services