One of the major global challenges of the future will be to ensure access to fresh, potable water. Water vapour is a component of the flue gases produced in many industrial processes. The EU-funded CapWa project (‘Capture of Evaporated Water’) was set up to develop a method of recovering this ‘waste water’ using a single-phase membrane technology, which would lead to considerable energy savings.
The water-selective membranes used in the trial application are hollow-fibre membranes with a fine coating of an extremely hydrophilic polymer developed especially for this project by EMI Twente. We were able to draw on the knowledge and expertise gained in several earlier research projects. A fully developed production process for the membranes, including all production parameters, was transferred to the project partners for further upscaling. The resulting membrane modules have been tested on a semi-industrial scale at a power plant in Israel. It proved possible to recover about 100 litres of water per hour using membranes with a total surface area of 30 m2.