More than 800 million people around the world have no access to clean drinking water. According to United Nations data, this number will increase to 3.3 billion. Because seawater has become an important source of drinking water in many parts of the world, the demand for more intelligent seawater desalination methods is increasing.
One of the basic challenges faced by modern seawater desalination is energy consumption. Seawater desalination plants need to use a lot of electricity generated by fossil fuels, which leads to more serious climate change.
Jiwoong Lee of the Chemistry Department of the University of Copenhagen invented a breakthrough technology, which uses carbon dioxide to convert seawater into drinking water without electricity.
"It's a bit like the SodaStream machine in many people's kitchens. You add some carbon dioxide to the water, and then a chemical process begins. But instead of using carbon dioxide for bubble carbonation, we use it to separate salt from water. " Jiwoong Lee explained that in addition to being a researcher and assistant professor in the Department of Chemistry, he is also the founder and CSO of CowaTech ApS, which is the derivative company of his invention patent.
The working principle of this technology is to add compound diamine to brine. The type of diamine used is carbon dioxide reactive, which means that its behavior can be controlled when it comes into contact with carbon dioxide. Diamines combine with the added carbon dioxide, then absorb the salt like a sponge, and then separate the salt. The whole process takes 1- 10 minutes. Once the carbon dioxide is removed, the salt will be released again-so that the chemicals can be reused in the next round of seawater desalination.
In the laboratory, in principle, this method can remove 99.6% of the salt in seawater. The technology is still under development, and one of the purposes is to reduce its price and optimize the recycling process with the lowest energy consumption.
"I've always wanted to apply my chemical research to good things. People usually associate chemistry with things that pollute water. But by using technologies that pollute our water sources, we can do the opposite. And we will not emit carbon dioxide, but make good use of it. " Li Jiwu said.
At present, this technology needs small-scale testing. The experimental equipment is a water bottle with a specially designed filter. These water bottles can be used as equipment for lifeboats or outdoor activities. CowaTech cooperated with Kapacitet A/S to produce a prototype bottle, which will be completed in 2-3 months.
In the long run, our goal is to apply this technology in a wider range as a substitute for today's seawater desalination plants. The plan is to use this technology to supplement the reverse osmosis device, which is the dominant seawater desalination method in the market at present. By doing so, CowaTech is expected to reduce energy consumption by 50%.