February 2013

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

Researcher:

Place:

Date:

Dennis de Vlieger, PhD candidate in the Catalytic Processes and Materials group (CPM) of Prof.dr.ir. Leon Lefferts (http://www.utwente.nl/tnw/cpm/)

Prof.dr. K. Seshan is his daily supervisor.

Meander room 117

24 January 2013

1. What is your background, how did you get where you are now?
“I have studied Chemical Technology at the University of Twente, both the Bachelor and the Master phase. I did my internship at the University of Potchefstroom (South Africa) were I first came into contact with a catalysis-based research project. It turned out that I really liked doing research on catalysis and therefore I decided to do my final Master project in the Catalytic Processes and Materials (CPM) group of prof. Lefferts. During this project I became even more enthousiastic about catalysis and its role in sustainable processes. Prof. Lefferts offered me a PhD position in his group, and I accepted right away.”

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

“During my Master project, I had to figure out how actually the chemical reaction of Water Gas Shift progressed on the surface of a catalyst, and this reaction came back partly in my PhD project. During WGS, hydrogen is formed by a reaction that involves carbon monoxide and water. Hydrogen is an important product for sustainable processes like cars driving on hydrogyn. In my PhD project, I’ve used aqueous (watery) waste - which are numerous in industry - which contain bio/organic molecules, like sugars dissolved in water. These sugars, we want to convert into hydrogen.”

MS: Actually, this research is a follow-up on the research of my first interviewed PhD candidate, Stijn Oudenhoven (interview 4 September 2012) He gets pyrolysis oil out of wooden waste (biomass) by heatening fastly without oxygen. Dennis continues:

“The pyrolysis oil can be divided into an aqueous phase and an organic phase. In this way, the oil gets a higher energy density and lower acidity. The organic phase is of interest for the production of bio-fuels. The organic phasel still contains a lot of oxygen, which has to be removed if you want to convert it into gasoline. This oxygen can be removed by treating the organic phase with hydrogen. In my project, I have taken the seperated water phase which contains sugars, alcohols and acetic acids. These subtances are now considered as waste, but what we want to do is, with use of a catalyst, to convert these substances to hydrogen. This hydrogen, we can use to upgrade the bio oil into gasoline. It’s very expensive to get rid of waste, and hydrogen is expensive as well (like € 2000 per ton) so it’s really worthwhile to process the waste for this goal!

My project involved the development of a catalyst for this process. A catalyst is a compound that helps to speed up the reaction, while controlling the products that are being formed.
On lab scale, we have developed a very good catalyst. We can realise the hydrogen process within a few seconds - which is relevant for industry. This catalyst is also stable for a long period (like 8 hours), making large amounts of hydrogen.”

How did you get this catalyst?

“We started with a platinum on alumina supported catalyst. We used aluminum spheres of 300-600 micrometer, with a very large surface because of the many pores in it. On this sphere, we put tiny platinum particles, that do the actual job. That catalyst lost its activity, because of the acetic acid in the feed stream. This acid made the aluminum migrate and covering the platinum surface, so that the molecules could not reach the platinum any longer, which stopped the reaction. So we had to find something else, a catalyst support that is not affected by acetic acid. Then we found - within our own CPM group - carbonnanotubes, which gave very good results!”

MS: The second part of the question ‘How does your research fit in the overall UT research’ can be easily answered. This research fits very well in the Top sector Energy, which promotes innovation in the field of green energy research. However, this pyrolysis process, on which you build, is not very ‘clean’, is it? It even smells like smoked sausage…

“What we mean when we speak of ‘clean energy’, is that there isn’t accumulation of carbon dioxide in the air. Furthermore, bio-oil contains less sulphur (which is responsible for acid rain!) than crude oil.”

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

Is it realistic to presume that in future, cars will run on pure bio gasoline?

“I don’t think gasoline can be replaced by bio fuel completely, because the demand for energy is too large. The edible parts of a plant can also be used for the production of bio-fuels. However, in a world where 30% of the global population is starving, it is ethically not correct to use food for energy needs. Therefore, we only want to use waste. (Instead of for example Brazil, where maize is being grown to produce bio ethanol…)But we’ll never reach the amount of waste materials to meet with the demand for energy. However, this already is an important contribution to cleaner fuel.”

What other application do you have for hydrogen, apart from bio fuel?

“Hydrogen is also being used for various processes in industry. For example removing sulphur from ‘normal’ oil. The quality of oil from the Middle East is getting poorer; it contains more and more sulphur. Burning sulphur gives acid rain. To get rid of one sulphur atom from the oil, you need one hydrogen atom. This prevention of acid rain is also an application of hydrogen.”

4. With whom do you work together? (other chairs, companies?)
“In the beginning, I didn’t have my own research unit but SPT (the group of Prof. Sascha Kersten – MS) had, and we had the catalyst, so we worked together and published an article together!
On congresses, in discussions with other researchers in this field, I have noticed that the University of Twente is leading on this subject, worldwide. Firstly, we have seen that the catalyst deactivated and how that happened exactly, which was not yet known in literature. Secondly, we have found a catalyst that does not deactivate during the reaction.”

Are you receiving subsidies, from companies for example?

“We get subsidy via the organisation ACTS (Advanced Chemical Technologies for Sustainability.)”

5. Will your research be continued after you’ve finished your PhD thesis?
On 8 February, you will defend your thesis, so that’s when the research stops… Or is there somebody who will continue with what you’ve found?

“Kamila Koichumanova (PhD candidate in CPM) has started research on the more fundamental side of the process. I have an engineering background, and therefore, I am more interested in applications. As I have always wanted to see where my research is applied, I prefer to work in industry. Right now, I’m applying on vacancies in the West of the Netherlands…

What I miss at university, is that we’d be so close to an application, but we wouldn’t continue…”

But what about the various spin offs the UT has generated?

“It is possible, but it’s still a risk to start a business nowadays. Besides, people also question whether the material of carbonnanotubes (the basis of the developed catalyst) would have risks for people’s health. Research is being done, but at this moment, it’s not clear at all. (In the lab, conditions are completely safe though!)

Thanks for this talk and good luck with your applications!