Polders and the Delta Works – Dutch water tech has not gone unnoticed in the world. It is what always stuck in the back of PhD candidate Qingdian Shu. Ultimately, he got stuck with the related CO2 capture theme – inventing a new green way to catch the gas. But it’s just the beginning, he humbly says.

The person behind the science and the science behind the person

Leeuwarden is the capital of Water Technology. Famous water tech oft stems from the Frisian province nowadays – and of course, the Netherlands in general. Even abroad, our country is seen as more than the land of tulips and cheese – polders and their water-pumping windmills are just as memorable.

It always stuck to the back of the mind of Chinese water supply engineer Qingdian Shu. So when it came to continuing his studies, he fittingly found the master’s Water technology. “I thought it would be great to study in the Netherlands. And in the capital of a province at that. Though I later learned that you have a different definition of a big city here.”

“And of course, because studying in the EU is different from doing so in China too. There, we are more focused on improving existing technologies. Here, complex, more abstract innovation is very much welcome.”

During his second year of study, Qingdian stumbled upon the beginning of such an invention – CO₂ capture from the air. Both his internship and thesis he did on the topic. As well as his PhD. “After I had done my studies in Leeuwarden for two years, I thought I wanted to do a PhD anywhere but Leeuwarden, but then the perfect chance came along.”

The CO₂ group was just developing as Shu arrived at the scene. “The theme evolved from the electrochemistry of the Blue Energy theme.” Having that almost alchemical knowledge and know-how on membranes, the researchers got into CO₂ capture.

Though catching the greenhouse gas is nothing new, the way to do it is not optimal. Using organic – often amine-based – solvents is not quite as green as the goal seems. Qingdian: “Especially if you consider that to extract CO₂ again, you need to put in a lot of energy and heat that can degrade the solvent too. Thus, replace it time and time again.”

“So I started to work on a concept to get carbon dioxide another way. We developed a column carrying a solid adsorbent that can adsorb it from the air with just renewable energy. But in the end, I feel like I became the biggest emitter,” he adds jokingly. “All the testing with adsorbing and releasing the CO₂.”

Just finding a location to test was not easy. Even what is to be expected to be the perfect testing grounds – the lab – was not suited. “We tried the lab, but with others doing their experiments around, it didn’t work. We could for instance tell when Chris was working on his animal manure research as our equipment recorded CO₂ spikes. So, we moved on to the roof, as we figured we’d have the cleanest air there. But there, we did not think about the boiler’s exhaust, so we finally settled for the bike shed.”

The capturing and release works by altering the acidity grade in the column. CO₂ adsorbs into the column at caustic levels, and in opposite circumstances, it rereleases the gas. The whole workings are delicately regulated through electricity and electrochemistry. That’s an entirely new green way of doing so, and required copious amounts of research time and energy, yet it sounds so simple in concept.

It illustrates the humble nature of Shu. He thinks his research is a mere beginning and that he can contribute so much more. When asked about his pride, it is in his students. And for now, he has been passing his knowledge on to the theme in a pre-post-doc concept. But what the future will bring, he doesn’t know yet. “Perhaps I want to explore other fields too. Not something with microbiology though; life is too unpredictable.”

Qingdian will defend his thesis on June 2.