Solar module breaks down plastic waste into hydrogen and other chemicals

Raw material from waste: A team at the University of Cambridge has developed a process to produce hydrogen from plastic waste using sunlight. The researchers say they have built a demonstrator that can be scaled up for commercial use.

The reactor, which Ariffin Bin Mohamad Annuar’s team describes in the journal Nature Chemical Engineering, consists of solar modules that do not generate any electricity. Instead, they initiate a chemical reaction that breaks down plastic, producing hydrogen and other valuable organic chemicals.

The reactor consists of a glass plate with an edge length of one meter. Various coatings are sprayed onto it. There is a light-absorbing layer at the bottom. On top of this lies a catalyst layer that contains, among other things, cobalt and zirconium.

The production is very simple: the layers are sprayed on using a device similar to a household paint spray gun. The reactor works in natural sunlight, as the team on the campus of the traditional university demonstrated: They placed the glass plate in a container containing a solution with pre-treated plastic and placed it in the sun.

Tested on university campus

“It surprised me how whole it was after all the optimizations,” said Mohamad Annuar. “We just take this big plate, spray our catalyst on it, dip it in our solution, put it in the sun, and it produces hydrogen and other valuable chemicals from plastic waste.”

The team said the process is therefore qualified to be used under real outdoor conditions and is also scalable. It has been working on the process for a long time. However, previous prototypes only worked on a laboratory scale and required high temperatures, aggressive chemicals or complicated manufacturing processes.

According to the researchers, the process can be used to break down a wide variety of materials, from cellulose to PET, which is used to make common plastic bottles. It is patent pending. Before it is suitable for large-scale use, researchers still need to improve the durability and efficiency of the reactors.

(wpl)