“I grew up with a deep love of nature,” says Dominique van Schalkwyk who will receive her master’s degree in Chemical Engineering on 9 December 2019. “When I first learned about climate change, I very quickly felt a need to protect that part of my childhood. This stuck with me during my high school days and when the time came to make a decision about what I want to do with my life, biofuels was my answer and chemical engineering was one of the ways to get there, so that’s what I did.”
“I obtained my bachelor’s degree in Chemical Engineering in December 2016 and initially I had no plans to carry on with postgrad. However, it was difficult to find work in Cape Town. When I saw an advert in which Prof Johann Görgens advertised a postgraduate opportunity in bioresource technology, I realised it tied in with my goals. The title of my master’s thesis is Techno-economic analysis of bio-oil production from forest residues via non-catalytic and catalytic pyrolysis processes.”
Dominique’s time at university has not all been plain sailing. She explains: “I have a vision impairment and struggled in my undergrad years, but the postgrad environment suited me better. Postgrad was a huge time of growth as it offered me opportunities to expand my ideas and thoughts. I regard my vision impairment as part of my journey. To walk this journey and be rewarded with a master’s degree cum laude for my hard work, feels as if I have redeemed myself.
“Now that I have completed my master’s, I would like to find work and gain experience before considering enrolling for a PhD. I would like to work in biofuels, bioenergy or renewable energy – even in bio-based chemicals and plastics. It is essential to me that the work I do in some way contributes to mitigating climate change and creating a more sustainable environment.”
Dominique is married to Helgard, a winemaker in Franschhoek. “He is very supportive,” she notes. “I am so grateful for the role he played in me getting my master’s. He took over the household, which allowed me to concentrate on my research. We have a great romance and amazing friendship. Although we have our serious moments, we share a lot of love and laughter and try to keep things light when we can. Helgard is very passionate about winemaking and it would be ideal if I could find a position in Cape Town or close to the winelands where I can start my career.”
Photograph: Nature lover Dominique van Schalkwyk in her element surrounded by vineyards and trees.
Title: Techno-economic and environmental analysis of bio-oil production from forest residues via non-catalytic and catalytic pyrolysis processes.
Summary: Forest residue is the woody biomass (e.g. treetops and branches) left behind in forests after felling and thinning operations. As a high fire risk, forest residues are often disposed of by controlled in-field burning or sold as firewood. Both inevitably contribute to air pollution and the latter has little economic value. The approximately 1,5 million dry tonnes of forest residues available in South Africa every year can instead be converted through pyrolysis, at elevated temperatures under an inert atmosphere, into liquid bio oil and solid biochar. Bio-oil can be co-processed with vacuum gas oil at an existing crude-oil refinery to produce bio derived fuel, while biochar can be applied to the soil for carbon sequestration and supplementation. Furthermore, bio-oil quality (measured by oxygen content) can be upgraded by introducing a catalyst in situ to the pyrolysis process. More upgraded bio oil compared to crude bio-oil can then be co-processed without significantly impacting product yield and quality at the refinery. The results showed a clear environmental benefit as both non catalytic and catalytic pyrolysis processes were carbon negative compared to the near carbon neutral process of burning forest residues. Moreover, the potential to reduce carbon emissions through co-processing crude or upgraded bio oil was significant. However for private investors, the commercialisation of bio-oil production via non-catalytic and catalytic pyrolysis processes was not cost-competitive with fossil fuel production. The commercialisation of these processes often hinges on crude-oil prices and government subsidisation. The next step is then to determine how much more refineries are willing to pay for bio-oil compared to fossil fuel based on both oxygen content and environmental benefit.
Photograph: Dominique van Schalkwyk.