Engineering Materials for Sustainability Is All-Hands-on-Deck Mission

Recent surveys indicate that there is a disconnect between investors’ and consumers’ willingness to pay for more sustainable products and manufacturers’ willingness to sacrifice some profitability to produce those products.

An EY survey in late 2022 showed that 78% of investors were willing to take a hit on profits to support more sustainable products, but only 55% of business leaders were willing to sacrifice some profitability to do so. Also, a 2023 McKinsey study indicated that consumers are willing to pay more for sustainable products. 

Chemical manufacturing comprises approximately 40% of US gross domestic product (GDP) but it is also a major contributor to climate change and environmental degradation. How can the plastics industry make the leap that investors and consumers say they want?

The road to sustainability less traveled

Answering this question was the goal of a July 2023 visioning event conducted by the Engineering Research Visioning Alliance (ERVA), a think tank funded by the US National Science Foundation (NSF). The event brought together 55 researchers, industry leaders, policymakers, and investors to identify innovative, less-explored lines of research that can transform all phases of material lifespans to make them more sustainable and circular. The event focused on the future of sustainable materials in three industry verticals — chemical, construction, and single-use consumer materials.

The results will be released in an upcoming report, "Engineering Materials for a Sustainable Future," which also was the subject of a Jan. 23 webinar presented by ERVA. The webinar previewed the report and addressed the following challenges for engineering research:

The webinar was conducted by Jennifer Dionne, senior associate vice provost, Research Platforms, Stanford University, and Yael Vodovotz, a professor at Ohio State University. These two subject matter experts developed the structure and scope of the research. The webinar was moderated by Rebecca Silveston, executive director of ERVA.

Engineering research is mission critical

Multidisciplinary engineering is needed at all stages of sustainable materials scenarios — design, scale-up, manufacturing, and end-of-use, ERVA said. Engineering research is critical for transitioning to the use of more sustainable materials.

The webinar discussed future engineering research directions in three areas:

Process and performance research to enable bio-based replacements for petroleum-based materials that meet product specifications. This includes engineering research that expands the role of microbes and enzymes in the material's lifespan, either to sustain it or to decompose materials selectively and efficiently at the end of their useful life.

Predictive models/simulations for all stages in material development encompassing atomistic-to-continuum structure property-function relationships to accurately represent the new materials' properties, processability, and performance.

Facility design to enable new feedstocks and low-temperature transformations at scale.

"Our focus is to find the most transformative engineering research needed to create a very sustainable material environment," Vodovotz said during the webinar. "Very different materials are involved, which is why we had so many subject matter experts. We need to design for sustainability from cradle to grave. This is very, very critical."

She said the scope of the work begins with molecules in the lab to large-scale production all the way to materials’ end of life. "Our concentration was looking 20-plus years down the road and how we get there. What are some of the issues and what resources do we need to get there?"

AI can accelerate process for finding solutions

Design is constructive and intuitive, Vodovotz said. "There are many different parts of the design paradigm that need to be addressed when we are looking at sustainability. Predictive models are helpful to the designer. AI is critical to minimize the number of experiments and speed up the process and look at a number of potential solutions."

The visioning event discussed new reactors and reactor configurations to handle new feedstocks. "If we are looking at more sustainable feedstocks, they might be waste-derived or [something] that is not currently being used, and maybe getting away from the petroleum-based products. We might be able to develop and use some hybrid biological and chemical catalysts." 

The visioning event discussed how biological materials and processes as well as waste-derived materials can be used to fabricate new materials. "Not only to design and fabricate them but maybe they can come apart more easily and be more regenerative," Vodovotz said. A guiding goal is being careful to maintain circularity and lower the carbon footprint.

Utilizing AI for material design will be a key to progress. "You want to begin by thinking: Where do I want to end up and how will this affect the overall circularity of the system?" Vodovotz said.

Designing better processes and materials to reduce global greenhouse gas emissions could have a huge impact on sustainability and a healthier planet, Dionne said during the webinar. "The largest contributors to global greenhouse gas emissions are the iron, steel, and construction materials industry, which accounts for about 8% of global carbon dioxide emissions; the chemical and plastics and refining industry, which accounts for about 12% of global carbon dioxide emissions; and the food and water processing industry, which accounts for about 3% of global carbon dioxide emissions."

The design space has great opportunities for progress. "It will require everything from improved computational models from the quantum and molecular dynamics level up to improved AI that can use the insights from autonomous or self-driving labs to help us hone in on what are better catalytic materials, all the way to designing engineered biological matter, such as engineered cells that can help us make more sustainable materials and proteins as products," Dionne said.

Scaling up solutions for sustainable manufacturing

After design progress is achieved, it will be critical to make sure that those designs and solutions have the ability to be scaled up and make their way into sustainable, manufacturing practices. "The ERVA participants spanning all the areas agreed that there needs to be focus [on applying] some of the design principles to create cost-effective, scalable technologies for catalytic transformations," she said. "That includes scalable technologies for bio-based engineering, for example. If you want to use cells as a factory in different bio-reactors, we need to make sure that we can scale up those cells in that manufacturing process and make sure that the whole system is essentially traceless, which means we are not emitting more CO₂ or leaving more waste once the conversion is complete."

The visioning event experts discussed how engineering can address solutions for both point capture of CO₂ and to lock CO₂ into materials for carbon capture. "Doing carbon capture in a scalable way is an area where the panel thought engineering could play a very significant role in the future," Dionne said. "The panel also was excited to think about how we could better optimize chemical separations and to efficiently extract CO₂ from industrial smokestacks, where there is a mixture of other gases that can be poisons for your catalysts. Figuring out how to do efficient gaseous separations to convert CO₂ into useful chemicals is a prime area for exploration."

Deconstructing consumer packaging narratives

They also discussed recycling or upcycling chemical separations in the concept of waste streams. Seeing how far we can take the "packaging materials or plastics that we rely on, that are multi-layered and multi-component materials, to be able to more efficiently separate them and enable better reuse and recycling of those materials," Dionne said.

Single-layer alternatives to some of the currently used multi-layered consumer packaging present a challenging opportunity. "Do we make sure that the mono materials have the same performance properties, and/or look at ways to take all that material apart?" asked Yael. "Perhaps something that triggers the end of life and allows it to degrade. Mono materials can be recycled much easier, but they also can be composted in the right conditions. We also want to look at enzymes and microbes that selectively and very efficiently decompose this material almost to monomeric units, because we want to avoid the nanoplastics and microplastics that are health issues. Can we move packaging and other materials into the composting arena?"

Developing better processes for end-of-life recyclability, while making sure that the product performance is maintained in a cost-effective way, is a key issue. "Automated sorting technologies are something that help us sort for very specific plastics, but we need to sort for more," Yael said. "There is quite a bit that ends up in landfills despite the sorting, so we need to work on these technologies. AI can play a very important roll here."

"We want to make sure that the findings here are actionable and valuable to the stakeholders in the community so they pick them up and put resources into them," said moderator Silveston. "ERVA’s mandate does not have funding [for this], so we try to make them as attractive as possible by finding the most important nascent research areas."