There is an acute shortage of good drinking water in many areas of the world. TNO had earlier developed a method, the Memstill® technology, to desalinate seawater using membranes and extract pure drinking water from it. The method has been taken a step further in its development and through a new principle that uses only solar or residual heat, it is possible to produce drinking water and electricity at the same time by pressurising the distillation.
There is significant interest in the TNO technology, MemPower®, from around the world and particularly in the Middle East. Having previously continued development of Memstill® in a European consortium, TNO will now be collaborating with parties in the Middle East including the water and electricity company KAHRAMAA from Qatar. The aim of the collaboration is to develop and demonstrate MemPower® for this region, working on improving the efficiency of the process by operating at a higher temperature and pressure. This results in a considerable increase in the amount of water and electricity produced. The joint proposition to achieve this was selected out of nearly 140 submissions by the Suqia Foundation in the United Arab Emirates as winner of the MBR Global Water Award 2016 in the category: innovative research and development – international institutes.
This becomes the third international award presented to an application of this membrane technology. In 2015 TNO received an innovation award in Saudi Arabia for the MemPower@ that had just been developed and in 2016 a European consortium coordinated by TNO won the EIT Innovation Award 2016 with the WE4CC-II project.
Existing methods of desalinating seawater tend to be complex, expensive and consume a lot of energy. TNO’s MemPower® uses renewable sources of energy like solar or residual heat to produce very pure water through a membrane filter technique. Rather than being a net consumer of electricity, using MemPower® actually produces electricity. Previous versions of the (non-pressurised) Memstill® process have been successfully demonstrated by TNO in large-scale testing at an electricity power plant on the Maasvlakte and in Singapore. For a long time it had been difficult to make leak-proof membrane modules but now there are parties in the market that have a good grasp of this technique. Operation of the first pressurised MemPower® modules have been recently tested at TNO with success.
In the food industry, too, where many diluted foods have to be thickened and brine reprocessed, the distillation methods offer new opportunities. Water is present in many areas of the world but the source is polluted. Memstill® and MemPower® can be used to make pure drinking water in these situations.
From 2013 to 2016 TNO was part of the Water & Energy for Climate Change (WE4CC-II) project together with TU Berlin, the Laborelec subsidiary of energy company Engie and Naked Energy Ltd, a manufacturer of new photovoltaic thermal (PVT) solar collectors. This generated cases in which solar heating, drinking water and conditioned air were combined in a single efficient system. This enables, for example, hotels on Mediterranean islands where clean water is scarce and expensive to make both drinking water from seawater and airconditioning using heat gained from PVT solar collectors and MemPower®.
The technology devised for making clean drinking water now appears to be suitable for the production of electricity, too. Using just solar heat as a source of energy, the standalone system can, in principle, be used anywhere in the world where water is present. Together with its partners, TNO will be working on perfecting the MemPower® prototype in the coming period to bring it closer to large-scale worldwide application.