Associate Professor Jakob Munkholt Christensen and PhD student Niels Dyreborg Nielsen in the lab. Photo by Thorkild Christensen

Can you store solar and wind?

Monday 05 Oct 20

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Jakob Munkholt Christensen
Associate Professor
DTU Chemical Engineering
+45 45 25 28 10

What is a catalyst?

The catalyst is an excipient that helps the reaction to happen. The better the catalyst, the easier the reaction takes place.
Solar and wind energy are difficult to store, but the liquid chemical methanol can be the key to being able to store up to 50 times as much energy in one place.

One of the challenges in making optimal use of energy from sun and wind is that the energy extracted is in the form of electricity and is difficult to store in periods with excess production from solar cells and windmills. This is because the amount of energy that is in, for example, a battery is quite small in relation to what the battery takes up. In Jakob Munkholt Christensen's group, they are now researching how to store much more energy in the same place:

"If you can convert the electrical energy from solar cells and wind turbines into a liquid chemical, you will be able to store 10, maybe even up to 50 times as much energy in the same place," says Jakob Munkholt Christensen, associate professor and researcher at the Center for Combustion and Harmful Emission (CHEC) at DTU Chemical Engineering.

The challenge is to condense the energy extracted from solar cells and wind turbines into less volume. Simplistically explained, this can be done by converting the extracted energy into hydrogen, which is then brought into a chemical reaction with the CO2 that anyway comes out of the chimneys from power plants and industrial plants. This gives you the liquid chemicals that can store energy efficiently.

Methanol is the focal point

One of the liquid chemicals that Jakob Munkholt Christensen finds particularly interesting is methanol:

“An industrial process that can form methanol from hydrogen and CO2 already exists. However, it is based on natural gas and not on renewable energy such as wind energy. The present industrial process requires very harsh conditions with high pressure and high temperatures, which necessitates that the industrial plants must be very large. This is why we are looking for a process that can be performed under less demanding conditions.”

In order to create such improvements, better catalysts need to be developed.

The trick is to understand the catalyst better

The work of the research group is therefore focused on gaining a detailed understanding of how the catalyst actually works.

"Our vision is to understand how the catalyst works in every detail, so that we can get rid of the bottlenecks that limit the rate of the reaction and identify the improvements that can make the chemical reaction easier," says Jakob Munkholt Christensen and continues:

“And we have actually had a breakthrough. We know now, that if you already have a little methanol from the start, it helps to form additional methanol more efficiently.”

According to Jakob Munkholt Christensen, the discovery is an important first step in relation to improving the process, and thus the practical application is one step closer.