© RUB, Marquard
In so-called extruders, the reactions are to take place entirely without harmful solvents.
Zoom in
If reactions for the chemical industry were to take place without solvents, an enormous amount of environmentally harmful or even toxic waste could be saved. Prof. Dr. Lars Borchardt has shown how this can be done: Together with his team, he realizes mechanically driven reactions in catalytically coated ball mills. To make this so-called direct mechanocatalysis marketable, it has to work on a large scale and continuously. For his work on this, the chemist from Ruhr University Bochum has received a Proof of Concept Grant from the European Research Council ERC. The project, called "MechanoExtrusion," will be funded with 150,000 euros for 18 months.
The chemical industry produces incredible amounts of waste. Solvents make up the bulk of it, many of them environmentally harmful or even toxic. Lars Borchardt's research group is developing synthesis concepts that not only reduce the use of solvents, but do without them altogether. "The concept is called mechanochemistry and is based on carrying out reactions in ball mills - solvent-free, solely by having balls collide with each other, thereby transferring mechanical energy to the solid reactants and causing them to react," the researcher explains. "Not a drop of solvent is needed to do this, so the whole thing is green and sustainable."
In recent years, the team has gone one step further and coated balls and grinding vessels with catalytically active components. This eliminates the need to add catalyst powders or molecular catalyst compounds. "These components are difficult to separate and reuse again," Borchardt explains. Instead, the grinding tools themselves serve as catalytically active components.
The researchers call this particularly sustainable process direct mechanocatalysis. It currently works on a laboratory scale. To be industrially applicable, it needs to run on a larger scale and continuously. "So the goal is to continuously fill reactants into a reactor, and the desired product is created in it just as continuously," says Lars Borchardt.
In his proof-of-concept project, the focus is on the so-called Suzuki coupling, one of the most important reactions in pharmaceutical chemistry. It is to take place in so-called extruders: a kind of meat grinder that can be continuously filled and ejects the desired product. The aim is to transfer direct mechanocatalysis from research to application. This is intended to create the framework conditions for a start-up.
Light and milling balls for greener chemical processes
A combination of photochemistry and mechanochemistry saves 98 per cent solvent and 80 per cent energy in a number of reactions. What’s more, the process takes less time than it does in solution. Light-driven chemical reactions so far were usually conducted with large amounts of solvents tha ... more
A new experiment has made it possible to observe the effects of an electron in solution on the surrounding liquid. So-called hydrated electrons play a major role in many physical, chemical and biological processes. They are not bound to an atom or molecule and are free in the solution. Sinc ... more
Tens of thousands of feasible catalysts on the diameter of a hair
When searching for catalysts for the energy transition, materials consisting of at least five elements are considered highly promising. But there are theoretically millions of them – how do we identify the most powerful one? A Bochum-based research team led by Professor Alfred Ludwig, head ... more
