Refinery integration of lignocellulose for automotive fuel production via the bioCRACK process and two-step co-hydrotreating of liquid phase pyrolysis oil and heavy gas oil

Klara Treusch working with the BtL-laboratory reactor





Klara, what brought you to BDI? What has your career been like so far?

In the course of my chemistry studies at the TU Graz, I applied for an internship at BDI in 2012. Through the Fem-Tech Initiative of the FFG, I subsequently got the internship.

During my time at BDI, I started writing my bachelor thesis and continued working part-time. My master’s thesis and my dissertation in the field of biomass to liquid technology followed, and ever since, I have been working full-time.

Nikolaus Schwaiger has accompanied me as my mentor throughout my training and since I started working at BDI. He now works as a lecturer at the TU and has also supervised my dissertation.


In your latest paper, you write about the possibility of using lignocellulosic biomass (e.g. wood or straw) to produce motor vehicle fuel. How did you come up with this idea?

BDI has been doing research on this topic for a long time and has already carried out a pilot project (“bioCRACK”), together with OMV. I have had the opportunity to work on this future-oriented project in the course of an FFG-funded research project. Personally, I think this topic is very exciting because it is possible to produce a sustainable biofuel from such a wonderful, diversely renewable resource, namely wood.


Could you please briefly outline how the project was structured?

For me, it started in 2012. The bioCRACK pilot plant has just been put into operation, and then I was involved in the analysis. In order to constantly optimize the pilot plant and to test different raw materials on a small scale, in our laboratory, we permanently carried out experiments which were then translated to the large pilot scale.

At the end of 2015, we received FFG’s commitment for further funding and started doing research on the topic of upgrading pyrolysis oil (which is a biogenic by-product of bioCRACK). This then became my topic for my dissertation at the Institute for Chemical Process Engineering and Environmental Technology at the TU Graz.


Nine other researchers worked on the paper with you. How did the team come about? Which qualifications were particularly important?

The project was structured in such a way that we conducted the experiments together with diploma and bachelor students of chemistry, chemical and pharmaceutical engineering and process engineering. It was important to me that the students were motivated and as enthusiastic regarding the topic as I was.

The project management on the part of the TU was carried out by my former BDI mentor, Priv.-Doz. Nikolaus Schwaiger, and we were supported and accompanied by Dr. Peter Pucher, head of the R&D BtL group.

Besides, we were always able to draw on the expertise of Prof. Siebenhofer, head of the Institute for Chemical Process Engineering and Environmental Technology, and he enabled us to devote ourselves fully to our project.


You have worked with very high temperatures (up to 400° Celsius) and high pressure (120 bars). What was most difficult for the team? The setup, the evaluation, or an intermediate step in the project?

Apart from the strict safety precautions when using hydrogen and working with high pressure (physically speaking), the greatest difficulty was the effort of each single experiment. To get the reactor sealed against hydrogen at 120 bars, prepare the catalyst and then achieve stable reaction conditions in the reactor, we already had to plan one working day for the ramp-up period. This means that each experiment was run continuously over several days, while we worked in shifts. Then there is the whole preparation and post-processing part, evaluation, analysis etc. This represents an immense effort on the part of personnel planning, especially at night, as there must always be at least two trained people on site for safety reasons. On the one hand, you have to find enough qualified people, and on the other hand you have to be able to fully rely on your colleagues.


What potential do you see in the use of lignocellulosic biomass for the production of fuel? Would you say that you have found an alternative to conventional, fossil fuels? Where is the journey going?

In the transport sector, a lot is currently happening regarding sustainability, CO2 neutrality, climate and environmental protection. Unfortunately, people disagree with each other  because no master solution has been found yet on how mobility will develop if we want to go on without fossil fuels.

In my opinion, this master solution will not be found in a single technology, as has been the case to date with the use of oil. Therefore, it is so important that research is being carried out simultaneously on different approaches to solutions (e-mobility, fuel cells, biomass to liquid (i.e. BtL), hybrid variants, to name but a few examples).

In my opinion, lignocellulosic biomass is a great piece of the energy puzzle. This technology should be considered especially in regions where this renewable raw material is available, and the wood industry is operated – i.e. where wood waste is produced.


What role do state subsidies play in research?

State subsidies play a major role. Numerous developments would not be possible without them. A company must make sure to work economically, to secure jobs etc. In such cases, work is more likely to be done on product adaptations and further developments, while no resources are allotted to new (usually costly) projects.

Fortunately, at BDI, we have a top infrastructure (laboratories, pilot plant etc.), and a good deal of resources are devoted to the development of new technologies. Above all, however, in the areas of recycling, CO2 reduction and climate protection – issues that affect us all –, government subsidies are simply needed to make progress.

For a small country like Austria, it is good to have an international reputation thanks to the development of such technologies, and to be able to keep up with the big players.


What advice do you have for women interested in science and technology if they want to gain a foothold in the technology sector?

“Everybody here puts his pants on the same way as you” – this line immediately comes to my mind, and it was my mom’s advice. After almost eight years in this profession, I can only say, “This is true!”

It would never have occurred to me that a man has more technical or scientific skills than a woman. If this seems to be the case, it’s more due to general social belief than due to missing technical skills! My advice to you women is, “Don't let it get you down!” On the one hand, we have to stand behind our competences, and on the other hand, rethinking the topic of “women in management positions/women in technology” must continue. At BDI, I appreciate having many highly qualified female colleagues, and that there are equal opportunities when it comes to hiring new staff.


Finally, we would like to know what direction your next projects will take. Would you already like to tell us what materials you will be investigating next?

At the moment, I’m improving myself further towards creating mass and energy balances for the engineering of industrial plants, as I simply love juggling with numbers. But there are already ideas for submitting an exciting topic for a funding proposal.


Dear Klara, thank you for your time. Would you like to add anything in conclusion?

I hope that we will continue to research in the direction of BtL and that I will have the opportunity to work with so many creative minds again.



This paper contributes to the integration of pyrolysis oil in standard refinery hydrotreating units for biogenous fuel production by co-processing. A two-step hydrodeoxygenation (HDO) process was performed at 80 and 120 bar hydrogen pressure. Liquid phase pyrolysis (LPP) oil was hydrodeoxygenated in a first step between 250 and 350 °C. An optimum between sufficient hydrophobation and high carbon yield in the product phase was determined at 300 °C. Co-processing was performed at 400 °C with 10 wt% of the mildly hydrotreated LPP oil in heavy gas oil (HGO). During the co-processing step, a stable operation mode and constant product quality without pressure dependency in the range of 80 to 120 bar was observed. The experimental outcome as well as product quality and carbon yield were the same as for reference experiments without admixture of pre-treated LPP oil. The products contained no residual oxygen and showed a high H/C ratio, equal to that of HGO.

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Refinery integration of lignocellulose for automotive fuel production via the bioCRACK process and two-step co-hydrotreating of liquid phase pyrolysis oil and heavy gas oil