September

The University of Twente’s Green Energy Initiative wants to give researchers the opportunity to show what they’re working at. This is the first of a series of interviews, in which Marion Steenbergen picks out one of the personal stories within UT’s energy research themes.

Researcher: Stijn Oudenhoven, PhD student in the Sustainable Process Technology group (SPT) of professor Sascha Kersten.

Place: Sustainable Energy Lab (Hogedruklab)

Date:Tuesday 17 July 2012

1.	What is your background, how did you get where you are now?

“I studied chemical engineering at the Saxion Hogeschool in Enschede. I did the Master phase at the University of Twente where I graduated on the upgrading of pyrolysis oil to transportation fuels. I started my PhD research in February 2012 within the SPT group, looking at fast pyrolysis based bio-refining schemes for the production of fuels and/or chemicals from lignocellulosic biomass.”

2.	What are you doing and where does your research fit in the overall UT research?

“Biomass can be converted into a liquid, which can be used as fuel, via fast pyrolysis. Pyro=fire, lysis=break down. What happens is that the biomass, for example wood or straw, is heated quickly to 500 degrees Celsius without letting oxygen to it. This causes the biomass to decompose into gasses, oil and char. What I want to do, is to develop a pyrolysis process that produces several product streams which are concentrated in targeted compounds. Thereby improving the further applications, like feedstock for chemical/petrochemical industry, and increasing the economic value of the process. Currently, I am focusing on three product streams: one rich in sugars, one in aromatics and one in light chemicals, such as acetic acid.” (See figure 1.)

A crucial step in this pyrolysis process is to improve the selectivity during the pyrolysis, for instance to increase the sugar yield, which is obtained by removing the minerals from the biomass before the pyrolysis. The minerals are removed by ‘washing’ with an acidic solution, which is being made within the pyrolysis process. In the beginning, Stijn used an actual washing machine, but that didn’t work very well; it couldn’t handle that much acid!

Stijns research fits very well in the University of Twente Sustainable Campus concept; in the near future, the local companies BTG and Opra will realise, together with UT, a turbine next to the Sustainable Energy Lab. In this turbine, pyrolysis oil will be burnt for various purposes. Read more information about the development of green gas turbines and the largest wood-residue-fired power plant in the world.

3.	How will society benefit, on the long term?

“Technically, it could be achieved to replace a part of the fossil fuels with biomass for the production of transportation fuels or chemicals. However, the future of using pyrolysis products is mostly in the hands of governments, whether they’re willing to subsidise. As long as crude oil and coal are still available at relatively low prices, I’d stay rather sceptical about the future of fast pyrolysis of biomass.

Another problem is the availability of biomass - like wood and straw - in the Netherlands; we’d have to import it from countries like Canada.”

4.	With whom do you work together? (other chairs, companies?)

“My project is funded by the CatchBio programme (www.catchbio.com), in which the Dutch government, industrial- and academic partners work together. I’m working in a cluster together with the CPM group (UT) of Prof. Seshan as well as the chemical engineering department (RUG) of Prof. Heeres. Twice a year we gather with the industrial partners (Shell / DSM), to present and discuss our research progress.”

5.	(You’ve just begun so it’s a bit premature, but all the same:) Will your research be continued after you’ve finished your PhD thesis?

“Research on biomass has a relatively long history in the Netherlands; in the 1930’s and the 1970’s, there were revivals, due to crises. Now, we see another revival in the United States; as we speak, Ensyn is building a pyrolysis plant (150 ton/day) in Europe and within the Netherlands, BTG (http://www.btg-btl.com/index2.php) is planning to construct a (demonstration) pyrolysis plant in Hengelo and Nettenergy (http://nettenergy.com/index.php/nl/) is testing a mobile pyrolysis unit – a factory which moves to where the biomass is, instead of the biomass that needs to be transported to the factory.”

Apart from these examples of commercial applications, Stijn tells that students do find their way easily to the SPT group as well, to do their Master thesis. Perhaps because SPT has a fair share in UT education, which makes the group visible among students. Which is good, because after all, they are the ones who can make a difference for our future!