By Bonnie JamesDeputy News Editor
An initiative aimed at easing the environmental concerns faced by Qatar due to the discharge of brine generated from thermal desalination of seawater, the country’s main source of fresh water, has been launched at Qatar University.A pilot project to produce more fresh water from brine was inaugurated yesterday. Intended to evaluate ‘Membrane Distillation (MD) of desalination brines through low-grade waste heat,’ it is a collaborative effort between QU’s Chemical Engineering Department, ConocoPhillips, Kahramaa and Qatar Electricity and Water Company.QU had signed in last October a research agreement with ConocoPhillips Water Technology, the operating company of the Global Water Sustainability Centre (GWSC), a joint venture established at Qatar Science and Technology Park between ConocoPhillips and GE Power and Water.“It is hard to think of an issue that is more pressing and vital than that of producing fresh water in our specific environmental context,” QU president Prof Sheikha Abdulla al-Misnad said at the inaugural event.Recalling that research activity has grown considerably at QU over the past several years, she explained that the national varsity’s aim is to be at the forefront of research that is relevant to the society, improves lives and offers real solutions.
Given the rate of expansion and development in Qatar and the subsequent demand for fresh water, the innovative work of the GWSC takes on even greater importance, Prof al-Misnad added.ConocoPhillips Qatar president Gary Sykes pointed out that the global energy major is unilaterally funding the project through its GWSC.“To my knowledge, this is the first field testing project in the Middle East and arguably in the world for such a unique application of MD technology,” he said.GWSC managing director Dr Samer Adham, who leads the ConocoPhillips investigation team, explained that MD is a simple process whereby water is first evaporated at low temperatures (50- 80C) and the vapour is passed through a membrane and then condensed, producing distilled water.This evaporation and condensation process is similar to the ‘thermal distillation’ processes used to produce all of Qatar’s drinking water.The key advantage of MD is that it can produce excellent quality distilled water from extremely saline water sources at low temperatures while using low-grade waste heat and/or energy from renewable sources.The two pilot plants installed in Qatar University campus and currently under initiation testing has a nominal capacity of 1000 litres per day.“This project will serve as a benchmark for technologies addressing the evaluation of the pros and cons of these different designs for our unique application in Qatar, in particular, and the Gulf region, in general,” Dr Adham said. With the success of this effort, ConocoPhillips may be looking at larger MD designs. The scale-up issues and pretreatment will be evaluated in the current research programme.The initial phase of testing is under controlled feed conditions. The units are to be moved to a local desalination plant of QEWC later in the summer for testing using actual brines from a thermal desalination process.Dr Adham was of the view that the MD process is a much more suitable process to desalinate high salinity water (salt content: 50 K- 100 K mg/L) as compared to reverse osmosis membrane process.“We believe that the application of MD in the Gulf states is to desalinate the brines from existing thermal desalination facilities is an ideal one as it can leverage the latent heat of the desalination brines and also harness the low-grade waste heat from power plants and/or nearby industrial facilities, resulting in lowering the environmental impact from discharging hot streams into the sea,” he said.The capacity of an existing desalination facility operating at full capacity can be increased without incurring new capital and operating costs associated with seawater intake infrastructure and pretreatment facilities. The end result is an overall higher product water recovery rate from the existing desalination facility.QEWC will provide access to its facilities for field-testing and Kahramaa will advise on the introduction of new water desalination technologies in Qatar. QU’s vice president of research Dr Hassan al-Derham maintained that the pilot project is very important for research given the dependence of Qatar on desalinated seawater.The principal investigator from QU for the project, Dr Farid Benyahia (professor and head of Chemical Engineering Department), gave an update and a video presentation on the pilot plants.