Testimonial

Dr.ir. Ellen Slegers – Assistant professor

Ellen studied Biotechnology and now works for the Department of Social Sciences at the Operations Research and Logistics group. Her research focus is on sustainable chains. In addition to conducting research, she also teaches sustainability related topics at Wageningen University & Research.

It is important that professionals know more about areas outside of their own field of expertise, for many puzzle pieces will fall in place if that would be so.

Ellen has been researching biobased topics since she began her PhD track. "When I started my PhD, the discussion was mainly focused around bio-fuels as an energy supply from microalgae, but it was still in lab phase. Commercial production was centred around cosmetics and nutraceuticals. These products are economically more feasible because of their higher return rate.

Since it is technically possible to produce biofuels from microalgae and, of course, the sun is free, I wondered what production outside would look like. Would it be economically feasible and what conditions would apply?.

These questions inspired me to develop models to translate lab results of growing microalgae from indoor to outdoor conditions. It is not only important to look at the production itself, but also at the supply chain.Of course, in the Netherlands, you have seasons, which you don’t have in the Sahara. However, you also need water.

The latter is harder to provide in the Sahara. Still, it is possible, both in the Netherlands and the Sahara, to cultivate microalgae. The reactor systems will look different, though."

The cultivation also requires adequate amounts of energy for circulation and carbon dioxide. Ellen looked into these factors, too. "The initial idea was to produce bio-diesel, which is very cheap in principle, but the pumping, cooling and heating costs a lot of energy and thus money too."

When Ellen conducted her research, more and more studies were published focusing on biorefinery. "If for example you only use microalgae for fuel," she said, "you use about 30% of the biomass. You don’t want to throw out the rest."

Therefore, in the last few years, Ellen looked at biorefinery chains. "The most sustainable way of cultivating and processing any type of biomass is by looking at the process chain from source to product. Knowledge of several kinds of downstream processing is essential since certain techniques will give high and low yields to certain products."

In her research, Ellen quantifies sustainability and includes it in the design and optimisation of biobased chains. "When you have a process chain, you want to know its sustainability. By knowing this, it is easier to identify the bottlenecks. However, it would be even better to optimise your process chain from the start onward by redesigning your process to be more sustainable. By redesigning, you combine models, data and sustainability analysis."

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