A team of scientists from the Norwegian University of Science and Technology (NTNU) has developed a new smart solution to purify wastewater and convert it to heat homes and businesses, and provide potable water.
The technology could use large amounts of industrial heat that would normally be wasted, while also generating clean water, the university said in a press release.
Industrial heat is a major component of global energy use, but once it is used in industrial processes, the remaining heat is released into the oceans or directly into the air. In Norway alone, it is estimated that this amounts to 20 terawatt hours of waste heat each year.
That’s about half of Norway’s household energy demand, or roughly the amount of energy Norway spends heating its homes. Kim Christiansen, a doctoral researcher at the Norwegian University of Science and Technology’s Department of Chemistry, wondered if there was a better way to treat this wasted heat.
In addition to heat, water from industrial processes is also a concern because it is polluted.
“If we evaporate this impure water through tiny pores in a water-repellent membrane, the condensed water that comes out the other side is drinkable,” Christiansen said in a statement.
This method is suitable for solid impurities that do not evaporate with water and can even help in processes such as seawater desalination.
Scientists propose using industrial waste heat to carry out this process, which could generate cleaner water on the other side of the membrane.
Christiansen has spent the past several years studying the complex effects of temperature differences when water is pumped across one side of a membrane and cooled on the other. He has developed theories to predict the effect on the membrane and then tested them in the lab.
Access to clean water may not be a problem in Norway, but the technology could help other industrialized countries meet water supply challenges around the world.