Inaugural Lectures: Profs Louw and Goosen share their journeys

In the broader sense, my work deals with how we can strengthen the food system (and the systems linked to the food system, like those of water and energy).

Why did I get involved in this work? Simply, because I think it matters, and because I admire farmers and what they achieve every day. I want to employ my engineering skills to support the work being done within the food system, and I do that by looking at methods that prevent valuable nutrients from going to waste, or I develop new methods to produce novel ingredients used in food (and hopefully also medicine in future).

How would you describe the relevance of your work?

It all plays into the broader theme of sustainability: How can we achieve better outcomes while also using less resources? Sustainability is a complex topic, and I’m not going to claim that I understand it all. But I do understand that there are still many inefficiencies in how we use resources, and I also understand that innovation is crucial to ensure there is a future for the next generation.

Can you give examples of how your research is applied in real-world contexts?

I’ve done quite a bit of work on developing specialist agricultural inputs by making use of by-products. This includes producing biostimulants (substances that help plants grow stronger, use nutrients more effectively, and better withstand stress like drought or heat) from fish by-products that are hydrolysed (broken down into smaller parts using water), and from seaweed material (fresh and by-products).

My colleagues and I have also patented a process that can recover a substantial amount of the cannabinoids (chemicals from the cannabis plant) that are lost when processors extract medical cannabinoids from plant material.

Can the agricultural, water and energy sectors work together to better utilise limited natural resources?

Theoretically, yes. Practically, it depends on the scale at which solutions are sought. If one would try, for example, to integrate the water, energy and food sectors for Southern Africa, it becomes extremely difficult to coordinate between role players across borders, who may have very different priorities.

Think of the Zambezi river. It starts in Angola, flows through six countries and is dammed in Zimbabwe, Zambia and Mozambique. Who gets to use the most water, and based on what criteria do they get to use a larger proportion? Now think about the hydroelectricity generated from the Zambezi (by using the power of moving water): Although no water flows through South Africa, we benefit a lot from hydroelectricity generated in Mozambique. Do we get a say in water allocation along the river?

In the face of increasing climate variability, we need to develop answers to these questions, but it’s a complex issue.

If one decreases the scale to a city, the geographic region to consider might become smaller, but the complexity doesn’t necessarily decrease. Even at smaller scales like single communities or single farms, it remains difficult to decide how resources should be allocated and utilised. Methods are being developed to help decision-makers better understand the issues and predict outcomes when changes are made in a complex system, but it’s not an easy field to work in.

Looking into your crystal ball, what developments do you see in bioenergy?

I see bioenergy solutions being viable when they fulfil a dual role, but as a stand-alone solution it might become difficult to justify. The issue is that biomass is so valuable as a source of materials, as a method to capture carbon from the atmosphere, or as a component of healthy ecosystems, that there must be a very good reason to convert it to an energy product.

An example could be subjecting organic waste to anaerobic digestion (breakdown of organic waste by microbes without oxygen), which (1) prevents organic material from decomposing into methane and causing significant environmental harm (methane is a much worse greenhouse gas than carbon dioxide), and (2) recovers energy from methane produced in a controlled fashion during anaerobic digestion. Another example is the partial gasification of, for example, invasive alien plants, to (1) produce a high energy gaseous product that also produces stable carbon that can enhance soil quality, while (2) also improving the ecosystem by removing invasive species.

Looking for applications where bioenergy is almost produced as a by-product of other processes will become increasingly important.

The higher education environment can be challenging. What keeps you motivated when things get tough?

The opportunity to contribute to the development of people keeps me motivated. My legacy will not be the body of research that I leave behind, but my contribution to training the next generation of engineers and researchers. The higher education sector is changing constantly, and at the moment quite rapidly. My role is to ensure I teach under- and postgraduates to think critically about the world around them, to be inquisitive, and to trust their own skills.

Tell us something exciting about yourself that people would not expect.

My brother and I still manage our family farm in the Eastern Cape Drakensberg. I think a cow is one of the wonders of the world, with the superpower of digesting material that a lot of other animals can’t (and converting it into something very useful to humanity: meat and milk). I also love black cats, and the one that owns me is the best feature in my house.

How do you spend your free time?

I don’t have a lot of free time. Over the last two years I acquired a copper pot still (a traditional device for distilling alcohol) and I’m learning how to make brandy, grappa and whiskey. I’ve also taken to a nice dry apple cider, so I’m learning how to brew that as well. I play some squash, I like a night at the theatre every now and then, I try to go hunting every year and I read a lot (fantasy mostly, but I’m running out of good material, so I also started branching into science fiction). And very importantly: I fish.

(Watch the inaugural lecture here.)

I’m interested in understanding new developments in machine learning and investigating ways in which they can be used to control and optimise processes in the chemicals and minerals industry. I’ve always enjoyed applied mathematics, but things really clicked for me during my undergraduate studies when I first encountered process modelling and control. Seeing how mathematics can be used to analyse the dynamics of complicated chemical processes I’ve been studying was wonderful. I’ve been fortunate to have the opportunity to continue working in the field as an academic.

How would you describe the relevance of your work?

Chemical engineers design and maintain the industrial processes that convert raw materials to valuable products, but these processes don’t run smoothly all the time. Process monitoring and control are necessary to ensure the processes operate safely and efficiently. These plants generate large volumes of data, which can be analysed using modern approaches to further optimise the process: that is where my work comes in.

Can you give examples of how your research is applied in real-world contexts?

Process engineers often find that the process isn’t operating quite as it should — this may indicate the presence of a fault. It’s usually difficult to find exactly where the fault is coming from: does the problem lie with a worn-out valve, or fouling on a heat exchanger? Machine learning can help with this: by analysing patterns in the data, the faults can be identified and the problem addressed.

What makes it difficult to implement and sustain machine learning technologies in the chemical and minerals processing industries?

I think there are two major challenges. First, it’s often quite difficult to get good measurements under very harsh process conditions: high temperatures, corrosive gases, etc. Without good measurements, analysing the data becomes much more challenging. Second, machine learning tools have become easily accessible in recent years, but traditional engineering training does not equip engineers with the statistical knowledge to correctly interpret the results. Providing industry practitioners with the necessary know-how is essential.

Looking into your crystal ball, what developments do you see in machine learning?

Large Language Models (LLMs) have really changed the way we think about machine learning. There are many ways in which LLMs can impact the processing industry, not the least of which is coding support. LLMs make it easier than ever for process engineers to start coding and developing their own data analytics tools. However, there are also really interesting developments in the use of neural networks for time series forecasting — that is, to predict process conditions. This will again be limited by available measurements. I think the use of machine learning to support the development of new “soft sensors” is very important for the field. “Soft sensors” use easily measured values to infer the properties of a system: for example, video imaging may be used to analyse how well a crusher (a machine that crushes big chunks of material into smaller ones) is performing.

Being part of a Machine Learning research group, what aspects of your work do you enjoy most?

I really enjoy studying the statistics and mathematics that underpin the various machine learning methods. But the best part of my work is definitely engaging with students and seeing how they develop in their ability to critically evaluate these complicated algorithms.

The higher education environment can be challenging. What keeps you motivated when things get tough?

As a Christian, I believe we have a sacred task of “ruling and subduing the earth”, which in modern parlance translates to wisely stewarding our resources. Chemical engineers create great value out of seemingly valueless raw materials: think of platinum from rocks. I think this is a worthy vocation, and we have a duty to do so in a way that is socially and environmentally responsible.

Secondly, I believe all people are created in the image of God. Knowing that the people you work with are wonderfully created and deeply loved has a real impact on my daily interactions, even though I still get it wrong much of the time!

These are the two cornerstones that keep me motivated: recognising the intrinsic value of the work that I do and the immeasurable value of the people that I work with.

Tell us something exciting about yourself that people would not expect.

I help organise a film club that meets monthly to watch a movie and discuss the ways in which the movie reflects our culture and our world; sometimes I even facilitate the conversation afterwards. We watch a wide variety of movies, from Barbie to Dunkirk, but my favourite by far is the 1987 classic Babette’s Feast.

How do you spend your free time?

I love playing board games. We have a board game group that meets every Sunday evening. We are a very competitive group, but also really good friends. I’m training my kids to be board gamers too.

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(Watch the inaugural lecture here.)