Refreshing efforts: Improving desalination technology to meet water demand

With little rainfall, scarce and depleting groundwater and high consumption per capita (see overview), Saudi Arabia is heavily reliant on desalination for water provision. As a consequence, the Kingdom is now the largest producer of desalinated water in the world and is investing heavily in new plants to keep up with demand, aiming to nearly double capacity in just a few years. However, the process is costly and energy-intensive. To address this Saudi Arabia is investing significant capital to develop new desalination technologies to improve efficiency of the process and bring in new and renewable sources of power for it, particularly solar energy.

Expansion

Removing salt from seawater to make it potable accounts for around 70% of drinking water consumed in the country. Saudi Arabia currently produces around 17% of the world’s total output of desalinated water, making it the global market leader in the field. To date, it has spent around $25bn on the construction and operation of desalination facilities, as well as on research into the field.

Despite its leading status, Saline Water Conversion Corporation (SWCC) aims to almost double capacity in the next three years, raising the Kingdom’s available output from around 3.3m litres per day in 2012 to 6m litres by 2015. To meet this target, three new desalination plants are being built at a cost of SR67.5bn ($18bn) are scheduled to enter into operation by 2015, with another $18.75bn of projects programmed to follow. Major projects in the pipeline include the $5bn Ras al Zour power and desalination plant, which will have a capacity of 1.03m cu metres of water per day when it comes on-stream in the first quarter of 2014, and the second phase of the Yanbu desalination and power plant, which will see its capacity increase by 60,000 cu metres per day at a cost of $1.05bn, also by 2014.

Research & Development (R&D) 

In addition to new production facilities, the Kingdom is also focusing on R&D to improve efficiency and bring down the high energy consumption of the desalination process. Leading desalination R&D in the Kingdom is SWCC’s Saline Water Desalination Research Institute (SWDRI) in Jubail. SWDRI has conducted over 400 studies in the field, more than 150 of which have been published. Its major achievements include establishing a patent for a desalination method involving the use of both nano-filtration membranes and, at a later stage in the process, either thermal or reverse osmosis units.

Another leading research facility is the Water Desalination and Reuse Centre at King Abdullah University of Science and Technology (KAUST), focusing primarily on membrane-based technology, including ceramic membranes, membrane distillation and forward osmosis. The institution is also working on thermal-based desalination with industrial partners. In addition to the development of new desalination technologies, the centre is also looking at issues like the environmental impact of desalination, as well as partial desalination for use in farming and aquaculture.

Linking Up

The Kingdom is cooperating with international institutions and firms, including major players in the chemicals and technology sectors, to advance research in the field. In July 2012 King Saud University announced a new chair in desalination research, funded by the UN Education, Scientific and Cultural Organisation (UNESCO). The chair is charged with examining existing desalination technologies and patterns of water consumption in the Kingdom, as well as potential uses of membrane-based desalination methods, with a view to providing guidance on maintaining a sustainable desalination programme.

In March 2012 the SWCC signed a memorandum of understanding with US giant Dow Chemical to share insights into desalination and jointly undertake research into development of the field. Dow has a history of using the Kingdom as a regional base for R&D in water utilities, having previously established a research facility, the Dow Middle East and Africa R&D Centre, at the KAUST, with a special focus on water treatment. This announcement was followed in July 2011 with Dow reporting its plans to establish a production facility for a variety of components of its reverse osmosis desalination technologies in Saudi Arabia.

Solar Needs

Solar-powered salt removal is a major part of Saudi Arabia’s desalination programme. Success in solar salt removal is key for the long-term sustainability of desalination efforts, as the activity is highly energy-intensive, and growth in energy consumption is threatening the Kingdom’s economic future (see overview). The SWCC has conducted several pilot projects in solar-powered desalination, and research has yielded results that are now being put to practical use. In 2012 the King Abdullah City for Science and Technology (KACST) launched a new solar-powered facility in Al Khafji in the country’s north-east that uses concentrated photovoltaic technology and water filtration technology developed at the KACST/IBM Joint Centre for Nanotechnology Research. The plant has a capacity of 30,000 cu metres per day and is currently the largest solar-powered desalination facility in the world. Another solar-powered desalination facility is in operation in Jubail. In October 2012 the SWCC announced plans for three more: in Dhuba, Farasan and Haqel.

In the research for the Al Khafji facility, KACST and IBM looked at the use of nano-membranes for desalination via reverse osmosis (RO) and various methods of using photovoltaics to transform light into electricity, as well as using organocatalysis to create new materials from oil. Researchers who worked on the project say that the membranes they developed provided an “excellent combination of salt rejection and water flux” and “have significant advantage over conventional RO membrane polymers”, including improved resistance to oxidation and the ability to “readily” remove arsenic salts and boron. The team also developed hydrogel coatings that provide “good” resistance to fouling by organic and biomolecules, improving water flux over the long term. Other centres in the region furthering these studies include the Environment Agency Abu Dhabi, which is currently conducting a trial involving the construction of 30 small solar-powered plants in the UAE.

Like Dow, other firms are also opening production facilities for manufacturing desalination technology components. Arabian Japanese Membrane Company – whose ownership is divided between Saudi firm ACWA (49% share) and Japanese firms Toyobo (36.1%) and Itochu (14.9%) – began producing RO elements in its factory in Rabigh City in May 2012.

Critical Importance

Given the water shortage and high demand, GCC states have been considering a plan to create a regional desalinated water pipeline network, which has the potential to import the commodity from neighbouring countries. However, such projects are in very early stages and domestic desalination still dominates efforts, with the process set to remain Saudi Arabia’s main source of potable water for the foreseeable future. In developing technologies to increase capacity and reduce costs, R&D efforts and monitoring use are critical to the Kingdom’s future.