Prof. dr. Gadi Rothenberg’s CatchBio project aims at converting biomass to BTX, a mixture of monoaromatic compounds. It’s all about finding the right catalyst. It must be able to break up plant cell wall component lignin in the right way. And it must do so at a cost that can compete with petroleum-derived BTX.
(photo by Jeroen Oerlemans)
Rothenberg heads the heterogeneous catalysis and sustainable chemistry group in the Van ‘t Hoff Institute for Molecular Sciences (HIMS) at the University of Amsterdam. His group researches and models catalysts and develops new materials for bulk chemicals and sustainable energy applications. Rothenberg also co-founded the company Yellow Diesel, that develops a new route for biodiesel production using solid catalysts.
In the CatchBio programme, Rothenberg collaborates with the Agrotechnology & Food Sciences Group of Wageningen University & Research Centre (WUR-A&F) on a novel route for converting biomass into aromatic compounds. Rothenberg: “If you take a tree and want to get energy from it, you can do two things: you can burn it, or you can let it rot anaerobically and make methane. Both methods are fine and much in use. But we think that we can do more with biomass.”
Existing techniques
Plants and trees are basically composed of cellulose, hemicellulose and lignin. Cellulose and hemicellulose are polysaccharides, that can be broken down to sugars and converted to biofuels. Lignin, on the other hand, is a big and complex molecule. Rothenberg: “Like cellulose and hemicellulose, lignin is usually burnt. It is difficult to process it any other way. But we want to break lignin up into BTX, a mixture of the aromatic components benzene, toluene and xylene. Currently, BTX is a product of traditional oil cracking. Lignin-derived BTX would be similar. That means that it can be processed using existing techniques. The industry wouldn't have to adopt new processes to use it.”
The concept is relatively simple, Rothenberg says, but it comes down to actually make it work. “That’s a bit harder. We’ll have to make the right catalysts and learn how to use them. That means we need a very thorough understanding of relevant catalysts and reaction chains. That’s why we collaborate with the research group of Jacco van Haveren of Wageningen University: we combine our knowledge on catalysts with their expertise on biomass processes.”
Practical approach
Proving that it is possible to break up lignin into BTX is just step one in the project, Rothenberg explains: “We want to find a process that’s economically viable. That means we have to manufacture BTX at a price that’s competitive with BTX made from crude oil.” That is typical of the CatchBio program, Rothenberg says: “It takes its input from the industry and aims at actual application. I really like this practical approach. I always try to spend part of my time on applied research. The other part of my time, just as important, I spend on pure curiosity-driven research.”