New tech turns industrial energy waste into drinking water, heat in Norway

A new technological approach developed by researchers at the Norwegian University of Science and Technology (NTNU) can achieve two goals in one.

The technology can use large amounts of industrial heat that are usually wasted while also generating clean water, a university press release said.

Industrial heat is a major component of global energy usage, but once utilized in industrial processes, the remaining heat is released into oceans or directly into the air. Estimates suggest that in Norway alone, this amounts to 20 TWh of waste heat every year.

This is approximately half the energy demand of households in Norway or roughly the amount of energy Norway spends on heating its homes. Kim Kristiansen, a doctoral researcher at the Department of Chemistry at NTNU, wondered if there was a better way to tackle this heat that was being wasted.

Solving two problems at once

Alongside heat, water from industrial processes is also a concern because it is contaminated. “If we evaporate this impure water through small pores in a water-repellent membrane, the condensed water that emerges on the other side is drinkable,” said Kristiansen in a statement.

The method is suited for solid impurities that do not evaporate with the water and can even help in processes such as seawater desalination .

The researchers suggest using industrial heat waste to carry out this process, which can generate cleaner water on the other side of the membrane.

Kristiansen has spent the past several years studying the intricate effects of temperature difference when water is pumped through one side of the membrane and when it cools down on the other. The researcher has developed theories to predict the effect on the membrane and then verified them in the lab.

Access to pure water may not be an issue in Norway, but the technology can help other industrialized countries face water supply challenges worldwide.

Slow uptake by the industry

Like all scientific developments, this solution is based on previous research carried out in a different country.

Researchers at the TNO laboratory in the Netherlands work on translating research concepts into real-life solutions. The team had built a prototype called MemPower that could generate water and power simultaneously but needed more funding to continue its work.

The work then continued at NTNU, but the industry that could reap its benefits has yet to warm up to the idea. Kristiansen attributes this to the persistent limitations of membrane technology across all sectors. Regarding harsh industrial conditions, membrane technology has failed to deliver high lifespans.

Kristiansen believes that the industry needs to be aware of the potential of technology like MemPower. “A lot of work is being done internationally in both academia and industry to meet these challenges and commercialize the technology,” he added in the press release .

His latest work also shows that the technology can be competitive with other membrane-based energy generation processes, which could lead to more commercial applications.

The research findings were published in the journal Desalination .