By Anne Bloksgaard Nielsen. Photo: Lars Horn

When using membranes for high-level water purification, one challenge is to ensure that not even the smallest particle of salt, chemicals or pollution can travel through the membrane into the purified water. The membrane research group at Aalborg University is among the leading in the world, and now, one of its young researchers is developing a new membrane technology based on thermal membrane distillation that may have a huge commercial potential.

The idea for the new membrane technology has its roots in a project that Xianzheng Ma was working on while he was a PhD student at Aalborg University:

"During my work on using membranes in the circular water economy – and the limitations of current membrane technology in some contexts – I got this idea for a kind of high-quality thermal membrane distillation where I use a new type of membrane to achieve, on the one hand, high-quality pure water, and on the other, minimizing the discharge of the wastewater", says Xianzheng Ma.

Based on green energy

With membrane distillation, the water that needs to be purified is heated until it becomes steam, and as the membrane is hydrophobic, steam can pass through, but the pollutants (or other substances dissolved in the water) and liquid water cannot.

The method has not been widely used, as, first, the type of heated process needed to turn the water into steam has been seen as comparatively expensive, and, second, the membrane needs to be able to function and be durable in a setup where one side of it is heated – to provide the steam – and the other is cooler for returning the steam to its liquid phase.

With the new membrane technology that Xianzheng Ma is developing, he is using a new membrane that is both steam-permeable and heat-resistant. In addition, the heating expenses can be kept low by consciously focusing the development of the technology on industries or areas where heat is readily available:

“The technology makes use of the fact that today, heat is readily available in many different areas. If we think geographically, in many parts of the world solar heating systems can drive the process, and in terms of industrial contexts, many large facilities have some kind of excess heat that could be channeled for this process. In this way, the technology can become a part of the green circular economy where we reuse as much energy as possible in our industrial processes – and at the same time it will facilitate increased recycling or upcycling of, for instance, wastewater or various chemicals,” he explains.

Major commercial potential

The new type of membrane distillation technology can potentially be used in a variety of contexts – maybe even as a sort of plug-and-play solution. An initial grant from Spinout Denmark and a subsequent grant from VILLUM Fondens P2X Accelerator Program have given Xianzheng Ma a unique opportunity to delve deep into the commercialization aspect of the technology alongside his work refining and maturing it.

“I am currently working on mapping out the various commercialization potentials of the technology, and we are right now working to get funding for the next stage where we will both develop the technology further and dive deeper into the application potential for the application areas that hold the most commercial potential. Providing drinking water is of course an option for a technology like this, but there are already a number of efficient technologies for that. Instead, we are looking into different industrial contexts – from the energy sector where ultra-pure water is crucial, over chemical industries that need to distill a specific compound from chemicals, and to food productions where you want to remove water from the dairy or beverages,” he explains and finishes:

"The aim is to turn FiBrane into a spinout company that focuses on water solutions and green energy. I hope that in the near future, I will be able to run a company based on technology full-time, but with close collaboration with the research environment here at the university that has the technology, the knowledge, and the young talents that I will need to be able to take the technology even further."