If the disciplines of engineering strive to maximise benefit while minimising risk, what role should chemical engineers play in balancing human development with the creation of an environmentally sustainable society?

Prof Harro von Blottnitz at his inaugural lecture, suggesting that he don green overalls instead of his academic rob, to signal the urgency of the global challenges we face – such as plastic pollution in our seas and climate change.

It is this question that Professor Harro von Blottnitz – known as an industrial ecologist, and based in the Department of Chemical Engineering – interrogated on 27 August 2014 in an inaugural lecture that exuded both warmth and humour.

In his introduction, Dean of Engineering & the Built Environment Professor Francis Petersen, described von Blottnitz's early years spent in what was then the occupied territory of South-West Africa, followed by his years as a student at UCT and later sojourns in Sasolburg and Aachen, Germany where he learnt how to transfer skills from the field of mineral processing to recycling technology. Von Blottnitz became a member of UCT staff in 1998.

A holistic view

"Sustainable development has always been the leitmotif of my work," said von Blottnitz. "Growing up in Swakopmund, I had an early intuitive introduction to life cycle assessment – a cradle-to-grave technique assessing the environmental aspects and potential impacts of a product or process. I saw firsthand the jobs and income that uranium mining brought to my town, while my cousin in Germany grew up in a community resisting the establishment of a nuclear waste disposal site in their backyard."

Among the numerous challenges currently facing our planet, von Blottnitz identified three in which chemical engineering had an important role to play: those of plastic pollution in our seas, the extraction of resources (including ores, fossil fuels, biomass and construction materials), and climate change. While his daughters provided a reminder of the problem of ocean waste, by displaying an array of plastic collected on Cape Town's beaches, von Blottnitz pointed out that in terms of climate change, global emissions have continued to rise, even in the face of attempts to decrease them.

Our planetary ecosystem

"These are global challenges and must be looked at from a global point of view,” he said. “If we look at the ecosphere, or planetary ecosystem, we can see that physical laws govern these processes. Indeed, from a thermodynamic point of view we can see the earth as a closed system which can cycle materials because of its energy balance. In effect, the earth is a giant heat engine."

Can human technology mimic these natural global processes so as to better manage the side effects of the industrial economy?

"I believe the answer to that is yes," says von Blottnitz, "however, to do so requires a great deal of joint action and collaboration – 'systems intelligence'. In my view, to create an environmentally sustainable society requires the closure of cycles of materials, which are powered by renewable resources."

Signalling a change from theory to the more practical part of the lecture, and also to illustrate the role of technology in the university classroom, von Blottnitz then asked the audience to fill out an online poll, which showed that 80% of them recycled and 25% had installed solar water heaters.

The current state of recycling

According to von Blottnitz, when it comes to recycling in South Africa, progress depends largely on the material in question. "Studies show that glass and paper are recycled to a greater extent than plastic and tyres," he explained. "In the case of plastic bottles, 48% of the 11 billion bottles produced in this country last year were recycled, with the recycling rate increasing year-on-year. This is largely due to the costs of recycling being built into the price of the product. Setting up such systems requires time and money, of course. In the case of tyres, where we have all been given a free ride up until now, this process is just beginning. Nonetheless, thanks to the Waste Act of 2008, the price of tyres will soon carry a levy of R2.30/kg so as to implement a system for their end-of-life collection and recycling."

Switching to renewable energy

In South Africa, as in many other countries, we are taking our first steps toward renewable energy sources. For example, the Kalkbult 25 megawatt solar power station came online in September 2013. But global fossil fuel emissions are still rising. Why?

Here von Blottnitz used a slide from the recent 5th assessment report of the International Panel on Climate Change to explain the multiple reasons: "Although the progress of technology makes it possible to use energy more efficiently, population growth and economic growth both drive emissions upward. Critically, our choice of fuels with a high carbon content in the last decade pushed global CO2 emissions in the wrong direction."

There are encouraging trends though, such as US emissions having peaked, and declining for the past five years.

The need for systems intelligence

As an example of the need for systems intelligence to be built into global processes, and in particular the necessity of tools such as life cycle assessment (LCA), von Blottnitz cited the example of the energy life cycle of biofuels, an area in which he has published some of his best-known work.

"When we started to look at whether biofuels were really the positive development they were billed to be, around 2002, we discovered some problems. While our work posed the question, it couldn't fully answer it at the time. Nonetheless, building on this question, a Californian team later confirmed that in some cases, such as US corn-ethanol production, biofuels have a higher ecological impact than more traditional fuels, such as gasoline – even though they have a lower carbon footprint. This directly points to the need to take a holistic view and to build systems intelligence.

"One definition of an engineer's job is to apply science to the benefit of humanity. To do this well, maximising benefit while minimising risk, engineers must use judgement and base it on ethics, including the moral necessity of conserving our ecosphere for future generations."

An appeal for collaboration

Von Blottnitz ended his lecture with an appeal. "As I stand here before you, I have been on the field for 20 years. While I hope to play for many more, I think Team Green needs fresh legs and so I am appealing to students to take up these challenges."

Von Blottnitz also made an appeal to his colleagues for collaboration on these issues, to the UCT executive to support the Green Campus Action Plan with an investment in renewables and, in his words, "to you, Mr President, to trust in the knowledge of local experts. Your democratic government employs skilled staff who have good processes to lead us through difficult decisions, such as those pertaining to shale gas and nuclear power. You do not want your administration to be the one blamed by future generations for having left a disastrous legacy!"

In closing, Head of Chemical Engineering Professor Alison Emslie Lewis spoke about von Blottnitz’s personal dedication to his professional pursuits, his "combination of idealism and deeply practical execution of the ideal" – which translate into his aspirations to become a raw food vegan, his involvement in the language Esperanto, and "his very personal commitment to recycling and using solar power": "Perhaps what summarises Harro most of all is the true and inseparable integration of Harro the person and Harro’s research area. He is so committed, so engaged and so deeply integrated into the subject of his research."