Water may seem to be everywhere, but a rising portion of the world's population may soon have hardly a drop to drink or use for growing food, supporting industries and cities, and preserving life-giving ecosystems. Recent statistics show that global water consumption has been twice that of population growth, and meeting this demand has become a key environmental and economic impediment facing many countries.
Driven by these factors, the desalination market has witnessed a significant upturn recently. Desalination represents an effective solution for addressing multiple environmental issues, including potential fresh water shortages, global warming, desertization and preserving the environment. The desalination industry has witnessed significant technological advancement to meet the growing demand for high corrosion resistance materials, energy efficiency and reliability.
Overview of RO Technology and Pump Application
Desalination is the process of removing dissolved minerals, which includes but is not limited to salt, from seawater. A number of techniques have been developed for desalination including reverse osmosis (RO), distillation, electrodialysis and vacuum freezing. The two most common technologies worldwide are reverse osmosis and distillation. Distillation is the process of heating and then evaporating the seawater to separate the dissolved minerals. In RO, the seawater is pumped through a membrane at pressure higher than osmotic pressure, thereby separating seawater and minerals. The quality of the produced water depends on various parameters such as water salinity, feed pressure, water temperature, membrane permeation number, etc.
The pump market revenue in desalination is high in RO technology compared to other unit types. The key components that comprise the heart of any RO system are the seawater intake pump, high pressure feed pump and RO membrane. The seawater intake and high pressure pump have been integral components of the RO system. However, the auxiliary pumps used for seawater pretreatment have recently increased in importance by improving membrane life and enhancing the quality of the potable water obtained in post treatment.
The high pressure pumps employed in a RO system are either positive displacement (PD) or centrifugal, depending on the size of the desalination plant. PD pumps are employed for plants with capacity less than 150,000-gpd since higher efficiency centrifugal pumps are not available for low flows. In constrast, centrifugal pumps are best suited for larger capacity as they have higher efficiency combined with less maintenance cost.
Growth Trends in Seawater Desalination
The demand for water, particularly desalinized water, is expected to increase and is considered a potential market particularly for pump manufacturers. The global market volume for desalination was approximately $4 billion in 2005 and is expected to reach almost $30 billion in 2015 with a growth rate of more than 15 percent per annum. According to recent statistics from the International Desalination Association, more than 13,000 desalination plants account for an installed capacity of 52 million-m3/day, and it is estimated that this will be more than double, increasing to about 107-m3/day by 2016.
The market share for RO seawater technology is currently 44 percent and has been dominant throughout the world except in the Middle East. However, based on the rising concern for energy savings and efficiency, the traditionally dominant distillate technology in the Middle East is expected to continue losing its share to reverse osmosis desalination. The market share of RO technology is estimated to grow close to 60 percent by 2015.
Geographically, the largest market for RO desalination still continues to be the Middle East and is expected to grow. In the future, Asia-Pacific is expected to experience a higher growth rate aided by its rapidly developing economy, urbanization and population growth. With environmental deterioration expected, governments are likely to look for new fresh water sources. America and Europe continue to be a steady market in which desalination plants are used for preserving rapidly depleting groundwater as an alternative water source.
Market Drivers
A number of factors have positively impacted growth in the desalination market. The key challenge for local authorities has been demand management, which means reconciling water shortages with increasing populations. Other alternatives to desalination are becoming comparatively more expensive, including water transfer, which until now has been the main alternative for regions with growing populations and inadequate local resources. The need for more fresh water has increased desalination usage and the size of RO plants installed. The throughput of any RO plant is governed by the feed water input, thereby aiding size increase of the seawater intake and high pressure feed pump.
Desalination is a highly energy intensive process. Divided by value chain, the biggest share in cost of the entire RO plant is its manufacture. The cost of converting seawater to fresh water has been influenced mainly by the energy cost and production cost, followed by operation and maintenance and installation, design, training and support. Recent developments in desalination technology have made it more economically viable by integrating other innovative technologies and processes and achieving maximized efficiencies in terms of operating cost and product quality that can provide a higher return on investments to the customers.
Replacing reverse running pumps with pelton turbines and then with pressure exchange devices to recover energy from the brine has brought significant cost savings. The efficiency of the pump used as energy recovery equipment is in the range of 70 to 75 percent compared to that of the latter, which extends up to 96 percent efficiency. As a result, the overall energy cost for the entire RO process has fallen drastically. Also, the increasing awareness and the need to produce water of higher quality have driven the increased installed capacity of auxiliary pumps used in the pretreatment and post treatment process in an RO plant.
Challenges Facing the Pump Industry
Key challenges for the pump manufacturer have been increasing water salinity and employing higher grades of materials. Global warming has had a significant impact in the rising seawater temperature and water salinity. This factor has lead to rapid corrosion of the material traditionally used in pumps, creating demand for a superior grade of material and increasing the capital cost of the equipment. The other major factor that can aid in the wider acceptance of desalination is improved life cycle cost of the equipment.
A focus on improved life cycle costs for desalination means pumps manufacturers must produce pumps with better efficiency and less required maintenance. If the seawater intake and high pressure pump essential to the RO system breaks down, the plant completely shuts down. Consequently, these pumps need to be similar to those operating in unspared services with higher reliability and longer mean time between repairs.
The environmental concern about desalination has been a major challenge for industry participants. There are no fatal flaws in desalination technology, and it has a substantial history of environmentally-safe operation. The major concern of environmentalists has been the discharge of highly concentrated brine back into the sea and chemicals added during the treatment process discharging into the sea along with the brine. This could have significant impact on the sea's ecological system.
Conclusion
With an inverse proportion between the rapidly increasing population and decreasing water availability, desalination will likely continue to gain momentum. As new technologies are developed and implemented, desalination will become a viable option for more communities worldwide as a means to maintain or expand water supplies. The market for pumps in the desalination industry, though it seems to be saturated, contains opportunities for both new equipment and upgrades/retrofits. Aging infrastructure in developed countries and the emergence of newer economies such as Latin America, Africa and Asia-Pacific should continue to boost the overall desalination market over the next several decades.
Pumps & Systems, January 2009