The biobased materials that will be used in industry more and more, have a major disadvantage: they mainly consist of water. Evaporating seems the most simple remedy, but this is very energy-inefficient: typically something you would like to avoid when making processes more sustainable. There are, however, other options that are driven by electricity and don’t have the need of warming the full volume of the material. Examples are hydrogels and membranes. In the project ELECTRIFIED, the University of Twente together with four other universities and eight companies, will explore these ‘electric dewatering’ technology. They expect to reach a decrease in energy consumption of 50 to 90 per cent.
Biomaterials, food, paper sludge: they all contain a lot of water, up to 95 per cent. Transporting these materials means transporting mainly water which is very inefficient. Does the material, at some point, enter an industrial process, the water has to be removed anyway. Heating up the full volume of the substance, causing the water to evaporate, consumes a lot of energy: this can vary between 15 and 25 per cent of the full energy consumption of the industry as a whole. This can hardly be called sustainable. But there are other ways to remove the water. It can be done electrically, without heating up. If this electricity comes from solar or wind sources, the full chain gets more sustainable.
Sissi de Beer, UT researcher in the Sustainable Polymer Chemistry group and programme director of Applied Physics, suggests using hydrogels that swell caused by water as long as an electric field is present. When an electric voltage is applied, the hydrogel shrinks and pushes out the water. A material like this is called an ‘electro-responsive hydrogel’ and it works like a sort of pump. De Beer and her colleague Mark Hempenius will further develop and improve this technique. De Beer already gained some experience in using a hydrogel like this: in that case, in the ReCoVR project, she uses it to extract valuable substances from a material. So, in a way, this works the other way round.
Within ELECTRIFIED, colleagues of other universities will do experiments with electrically charged membranes, or with electrical techniques for ‘pulling’ the water out of the pores of paper sludge. Several companies, from chemical industry, food industry and paper processing join this consortium. In the end, it will not be necessary to heat up the full volume of a substance to get the water out. In combination with the use of sustainable energy sources, the amount of energy can be reduced by even 50 to 90 per cent.
In the programme ELECTRIFIED, led by Professor Remko Boom of Wageningen University & Research, the University of Twente collaborates with TU Delft, TU Eindhoven and the University of Groningen. The companies involved are Avebe, DSM, VNP, Cosun, Corbion, Andritz, The Protein Brewery and Meam. The project is funded by the 'Key Technologies’ of the Dutch Knowledge and Innovation Covenant (KIC, press release of Dutch Research Council NWO)