A white jar in a University of Helsinki laboratory contains hemicellulose. This substance, which looks like fine crystal powder, is the focal point of Miia Kokkonen’s efforts.
A doctoral researcher in chemistry, she investigates which chemical reactions can be used to produce viable raw material from hemicellulose to manufacture plastics.
Underutilised wood components
Hemicellulose is one of the three primary building blocks of wood alongside cellulose and lignin.
While cellulose is used, for example, by the paper industry, the other two are not utilised optimally in any sector. They are often incinerated for energy. Compared to other wood pulp, not much thermal energy can be captured from hemicellulose.
“From the perspective of the chemical industry, it’s just wasted as well as being a source of emissions, as incineration releases carbon dioxide into the atmosphere.”
Kokkonen wants to put hemicellulose to use. She is writing her doctoral thesis in cooperation with Borealis, a company focused on new technical solutions and the circular economy, which provides polyolefin solutions, or plastic products, to the industry and consumers.
The study has one supervisor from the University and two from Borealis.
“Plastics are usually made from oil, which is not the most environmentally friendly source material. Hemicellulose is renewable, and it does not compete with food production.”
Kokkonen investigates the conversion of carbohydrates in hemicellulose into smaller molecules and their further processing into viable end products. She develops catalysts and investigates how to achieve the appropriate reaction conditions as easily as possible. Catalysts are substances that accelerate chemical reactions. At the same time, Kokkonen aims to create the desired product without any by-products – this is what chemists call high selectivity.
Hemicellulose and the catalyst don’t react at room temperature – the chemical reaction takes place in reactors providing a pressure above atmospheric pressure and a temperature of 100–200 centigrade. First, Kokkonen measures the hemicellulose and catalyst into a strong pressurised metal container called an autoclave, which she then takes under a fume hood.
“Once the reaction is complete, I analyse the content of the reaction mixture.”
Kokkonen became interested in mathematics and chemical and physical phenomena already in primary school. She wants to know how things work at the molecular level, which is now a part of her everyday work.
Chemists take advantage of research literature, but since Kokkonen is creating novel catalysts, she must also have the courage to rely on her own assumptions and estimates.
Kokkonen thinks that she may have the opportunity to create something that will benefit society as a whole through business collaboration.
At the same time, she gets to see what is not working. If a reaction requires too high a temperature and extreme pressure, its application on the factory floor may not be financially viable. This does not mean that such findings are not fascinating and worth investigating.
Four years to explore
After graduating with her master's degree, Kokkonen would have liked to find a job in the private sector. Noticing a University job ad for a doctoral researcher position, she thought it would be interesting to combine both worlds.
She is now involved in the
Kokkonen believes that the in-depth approach of doctoral research benefits businesses, as researchers always explore their research topics thoroughly. In turn, businesses take a practical perspective to things: how to turn research into business.
“If I create reactions in the laboratory with a few millilitres of material, you have to determine whether they could also take place on a larger scale in a factory where the materials involved in reactions are counted in tonnes.”
Kokkonen has now studied hemicellulose for two years. She has at least another two to examine its potential.