Carsten Könneker: Compared to other alternative energy sources, biomass is an exception: It can also be used in chemical production, not only to produce energy. Is this strategy worthwhile?
Regina Palkovits: Wood has been the basis of our civilization for several millennia. We used it for heating, cooking or housing. But it would be a mistake to see wood mainly as combustible material. Wood, or more precisely biomass - plant matter including forest residues like dead trees as well as crops like sugarcane or bamboo - is indeed a very interesting raw material for the chemical industry. In order to use biomass in industrial processes, we need to be able to utilise lignocellulose, the main component of most plants. The paper and textile industries already use it, the latter to produce viscose fibres. Researchers and companies are already working on new procedures. However, all of them have to become more cost-effective. But with rising oil prices, some of these procedures might become profitable sooner than we think.
Your research group is called "Heterogeneous catalysis and sustainable processes". What procedures are you currently working on?
As the name says, we are developing heterogeneous catalysts, meaning solid catalysts to treat liquid or gaseous materials. A well-known example are exhaust converters in cars: They transform exhaust gases into harmless end products. Similarly, special copper catalysts transform cellulose into sugar alcohols. These alcohols again are potential platform chemicals for future biorefineries – analogous to today's petroleum refineries that produce numerous end products from one source material. Momentarily, our main problem is that lignocellulose is insoluble. Unfortunately, the entire range of solvents used in chemical production is not applicable, and to make matters worse, lignocellulose cannot be vaporized. But in order to process it further, it has to be broken down chemically into its components.
What role do ionic liquids, or liquid salts, play in your research strategy?
Ionic liquids are a new, very interesting type of solvents. These are organic salts that are liquid below 100 degrees Celsius because their huge ions hamper the formation of a crystal lattice. But these salts are still quite expensive. This is the reason why our research association Tailor-Made Fuels from Biomass concentrates on a combination of classic solvents with liquid salts. In my opinion, this is a very promising approach. Some institutes abroad and some companies also experiment with micro-organisms to disintegrate lignocellulose. In the long run, our common goal is to dissolve lignocellulose under moderate conditions, with water as the only solvent.
Any use of biomass competes with food production: Isn't this a huge ethical topic in your research area?
But are there any alternatives to biomass, like household waste or recycled wood? And how energy-intensive would these alternatives be?
Already today, waste incineration plants use household waste to produce heat and electricity, in addition to classic recycling efforts. A different waste-to-energy strategy would be the liquefaction of waste with the help of catalysts, like in the famous Fischer-Tropsch process that generates synthetic fuels. But researchers always try to think ahead: Wouldn't it be great to be able to break down the plastic of an old bottle into its source materials? Processes like these need energy, but not necessarily a lot. If we could find an extremely effective catalyst, we might be able to design procedures that work with sunlight and water alone. These are the processes I dream about: A marked-off section at a trash dump with a water basin and a few mirrors to reflect the sunlight – and recycling may begin! Sometimes unconventional thinking is called for to achieve scientific progress.
Some people consider you to be "the German pop star of chemistry": young, successful, an excellent scientist – and a woman in a male-dominated field. Do you see yourself as a role model?
Actually it took me some time to realise that others might see me this way. Initially I went to an all-girls school where I was no exception in any way. Next, I studied chemical engineering, back then a small degree programme with few female students. But in our everyday work, it never mattered that we were only a few women. Only after I received my PhD I found myself in a category with significantly fewer women. And yes, people probably need role models: They feel more at ease when they know, "This is a career path that might work out for me as well". Some of my female doctoral students ask me, "Do you think I could do this as well?" Next, they often say, "But I also want a family", and this is when it starts to get difficult. Some female PhD students tell me, "After my degree, I want a corporate job, because balancing work and family will be far easier in industry than in science". A job in business or industry might have regular ten hour days, but after that everybody may go home. There is still a long way to go for women to combine career and family.
Why are girls still having a hard time to choose careers in natural sciences or engineering?
I think one reason is that the public image of an engineer's professional life is outdated. People still think that engineers sit all alone in their offices all day. But engineering today often means interdisciplinary teams communicating about their findings and having to present them to the outside world – women are supposed to be good at this sort of thing. And working in a diverse team should be attractive, let alone the manifold application areas: Young women could tell themselves, "I might even help securing our planet's future if I become an engineer for water treatment or for renewable energy!"
Dear professor Palkovits, thank you very much for this interesting conversation.
Interview: Carsten Könneker, assisted by Kirsten Baumbusch
English version: Susanne Dambeck (© Spektrum der Wissenschaft)