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Feature

Brent Young: Models of Sustainability

28 June 2021
Waipapa Taumata Rau, University of ƵProfessor Brent Young is working to help industry de-risk change through digital modelling

Imagine you’re a factory owner who wants to make your operations more sustainable. Where do you start? If your machines currently run on fossil fuels, they might be expensive to replace or convert. The new equipment might not run smoothly. You might incur unexpected costs. You might need to change your processes. You might even find your carbon footprint doesn’t shrink as much as you expect. 

Change is fraught with risk. Risk can be expensive. Yet the rewards of sustainability can be great both for a business’s bottom line and for the planet. That’s why Waipapa Taumata Rau, University of ƵProfessor  is working to help industry de-risk change, particularly in favour of sustainability.

Brent Young

Creating digital twins

To make change more predictable, Young, a member of the  department, is working with a number of companies to model process systems by creating digital twins of those systems.

Young’s digital twins aren’t avatars or chatbots. They’re detailed models of factories and processes, hyper-realistic not in the sense of skin tones or mannerisms but in their inputs, functions and outputs. His computer-based models follow the laws of physics, chemistry and biology. They account for predictable events such as equipment ageing or getting gummed up as well as unpredictable ones such as power outages and earthquakes. 

"You can really stress the system and push it in ways you wouldn’t push the real process because it would be expensive or dangerous to do. Sometimes you come up with really interesting, counterintuitive results.”

Brent Young

Once a digital twin is validated as running realistically, it can model what happens when circumstances change. For example, what happens when heat pumps are installed in a factory? When a company switches to renewables? More complex models are possible too. For example, a digital twin can model how a factory will interact with community infrastructure if it becomes a net producer of renewable energy rather than a consumer. 

“Digital twins allow you to engage in supported thought experiments,” says Young. “You can really stress the system and push it in ways you wouldn’t push the real process because it would be expensive or dangerous to do. Sometimes you come up with really interesting, counterintuitive results.”

From efficiency to sustainability

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Milk powder plant and digital twin

One important use for digital twins is to help industry increase efficiency. Greater efficiency can make processes more sustainable by decreasing energy and material inputs.

Some of the early work Young did in digital modelling was in helping water treatment plants use less energy to achieve the same or better clean-water outcomes. More than a decade ago, he won awards for work he did in that area with the Māngere Wastewater Treatment Plant.

Efficiency is also important when sustainability goals make processes more complex. For example, recycling or repurposing materials that would previously have gone into the waste stream adds additional steps for industry. Digital modelling can help optimise these types of circular-economy processes.

“Efficiency is an important step on the journey to sustainability,” says Young. “However, one thing I’m aware of is the Jevons paradox. William Stanley Jevons was an English economist in the 19th century and he observed that if you make things more efficient, you tend to use them more. If you’re talking about resources, you potentially use more of them rather than less. So from a sustainability point of view, efficiency alone isn’t the answer.”

“All these processes need to be cost-effective to be viable. Modelling can show how to make them economically feasible. Also, if industry doesn’t understand a technology or finds it too risky, it’s not going to be adopted. Through modelling, we can make sure the technology is understandable and ready for adoption.”

Brent Young

Modelling new solutions

Digital twins usually start with existing industrial processes. But what if a sustainable new process doesn’t yet exist on an industrial scale? Young is working with colleagues from the Faculty of Engineering to model these too.

With Senior Lecturer , Young is figuring out how best to recover phosphorus from wastewater.

“Phosphorus is in limited supply and there are predictions that if we continue at the current rate, mineable phosphorus might cease to be available within a century, maybe less,” says Young. “However, there’s phosphorus in wastewater, both from fertiliser runoff and from sewage sludge –our urine is one source of it. Technologies do exist to recover that phosphorus for reuse, so we’ve been doing lab work and modelling to understand those processes and optimise them.”

“Engineering is an applied science. I learn as much from people in industry as they learn from me. In academia, we have the luxury of thinking on a longer-term basis, while in industry, people have to make quick decisions on a daily basis. I like to think my work helps them serve the public.”

Brent Young

With Associate Professor Saeid Baroutian, Young is working to optimise technologies such as hydrothermal processing and supercritical extraction, which can break down toxic materials and extract valuable compounds from what would otherwise be waste. 

Also with Baroutian, Young is researching ways to capture greenhouse gases used in operating rooms. Though carbon dioxide is the best-known greenhouse gas, anaesthetic gases such as desflurane and sevoflurane are, molecule for molecule, far more potent in their ability to warm the planet. Currently, the anaesthetic gas patients exhale is simply vented out of hospitals. Baroutian and Young are looking at ways to absorb these gases before they hit the atmosphere.

“All these processes need to be cost-effective to be viable,” says Young. “Modelling can show how to make them economically feasible.

“Also, if industry doesn’t understand a technology or finds it too risky, it’s not going to be adopted. Through modelling, we can make sure the technology is understandable and ready for adoption.”

For years, UniServices has been helping Young make connections with industry and secure funding for his and his graduate students’ research. He says keeping his research relevant is part of what drives him.

“Engineering is an applied science,” says Young. “I learn as much from people in industry as they learn from me. In academia, we have the luxury of thinking on a longer-term basis, while in industry, people have to make quick decisions on a daily basis. I like to think my work helps them serve the public. Also, how do we clean up the mess we’re making on the planet? How do we do better in the future? These are the questions that increasingly motivate me.”

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