Manufacturing is critical to our way of life. Without it, we wouldn’t have the supplies, food, clothing, electronics, and other things we use every day. However, manufacturing also produces waste that often ends up in landfills or oceans. 

Looking at natural ecosystems provides a different perspective on this conundrum. There’s little waste in nature. For example, certain bacteria and fungi decompose dead organic matter, reintroducing nutrients back into the soil for plants to use as they grow. 

This inspires the question: What if one manufacturer’s trash could be another one’s treasure?

Companies could save on waste disposal and raw-material sourcing costs. Our planet would also benefit by keeping potentially valuable materials out of landfills. 

For example, many companies don’t need pristine or drinkable water for their manufacturing processes. So, rather than used water being discarded, it could be used by another company for its own operations. This concept of resource sharing and waste exchange through mutually beneficial partnerships is called industrial symbiosis. 

Industrial symbiotic arrangements allow companies located near each other to share resources easily. The costs to transport materials between different businesses will presumably be lower if they’re near each other. 

Industrial symbiosis is already being used in some parts of the world. The Kalundborg Industrial Symbiosis in Denmark is a famous example of this approach. During the last 50 years, the Kalundborg partnerships have grown organically through increased awareness of their economic and environmental benefits. Currently, 17 partner businesses are exchanging more than 30 different types of materials, such as water, sand, and ethanol waste. As of 2020, the symbiosis had reportedly saved 4 billion liters of groundwater. This partnership reduced so much waste that the local energy supply has become carbon-neutral.

However, not all attempts at industrial symbiosis are successful. There are multiple challenges to developing these projects. These include the awareness and identification of compatible waste exchange streams, contract negotiations among companies, and a lack of knowledge about what makes the arrangements successful.

That’s why I joined the manufacturing in a circular economy research team at NIST as a postdoctoral researcher to understand what makes these networks successful and how we can measure their success.

Engineering standards for industrial symbiosis 

Industrial symbiotic partnerships, such as those highlighted in the Kalundborg example, were acknowledged in a new international standard as an important step in making our economy more circular. Now more than ever, it’s important that we develop metrics and evaluation methods to understand the health and viability of these types of partnerships.   

Companies interested in industrial symbiosis want to know how it will benefit them and whether the effort will be worth their time and financial investment. Additionally, if a business can divert waste using one of these partnerships, and a local government wants to reward it with a tax break, that government would want to know the company is meeting its stated sustainability goals. 

But before a standard can be created, we must study the problem. That’s where our team—along with other researchers—comes in. 

I recently studied various examples of real-world industrial symbiosis projects, both newer and more established efforts. My goal was to see what I could learn about what makes such a project successful. Comparing these programs allows the organizations running them to learn from the best practices and experiences of others. 

Credit: inspiring.team/Shutterstock

Our work was recently published in the Journal of Cleaner Production, which discussed seven factors that affect the success of these arrangements. 

For example, successful long-term industrial symbiosis projects reuse significantly more materials than newer partnerships do. It’s not surprising that the more companies benefit from these arrangements, the more likely they are to stay in them for the long term, and that’s better for sustainability.  

Additionally, we studied the cohesiveness of the networks—specifically, how tight or loose their ties are to each other. Let’s say there’s an industrial symbiosis project in an area with one resource supplier and three consumer companies that supplier sells materials to. If that one supplier company leaves the partnership, the three consumer companies might also leave because they have no relationship with each other and no reason to work together. 

More mature industrial symbiosis networks, in contrast, had more tightly connected organizations with multiple different partnerships among one another. Newer ones had fewer partnerships and looser ties. 

Our research showed that we can study the characteristics of companies that make industrial symbiosis successful without needing access to sensitive, proprietary company information. This means companies can feel free to participate in future research like ours—which we ultimately hope will help make our economy more circular—without compromising their business. 

Becoming a sustainability researcher 

Sustainability and resilience are complex and multifaceted, and so is researching these topics. It’s not just science but also math, economics, and even a bit of sociology. Sustainability research gives me the opportunity to use my curiosity for mathematics and apply it to complex, real-world challenges.  

During my undergraduate education, I did internships at Georgia Tech, working on manufacturing techniques for hydrogen fuel cells. This experience further motivated me to pursue graduate research in sustainability and climate change. 

I also enjoy the highly collaborative nature of this research. That’s a necessity because of the interdependencies between various areas of our human-created environment, such as manufacturing, energy, and supply chains. 

In fact, my entry point into industrial symbiosis research was through a collaborative project. In that project, a colleague and I demonstrated a novel approach to industrial symbiosis partnerships that reduce consumption and businesses’ operating costs. 

Since I arrived at NIST as a postdoctoral researcher, I’ve involved myself in service and leadership roles within the sustainability and resilience research community. This year, I led the organization of a panel discussion with eminent experts in the areas of circular economy and sustainable manufacturing at the 2024 American Society of Mechanical Engineers’ Manufacturing Science and Engineering Conference. 

One takeaway from that discussion was the importance of using sustainability analyses early on in an engineering project so we can better understand the bigger-picture environmental impact of seemingly small decisions, such as choosing materials for a product. 

Looking ahead to an industrially symbiotic future 

The opportunities to work with a diverse group of practitioners and researchers motivate me to continue learning and advancing this field. I hope to continue working in infrastructure sustainability, resilience research, and implementation going forward in my career.

I hope that our study and future studies like it will help to scientifically demonstrate what makes industrial symbiosis groups successful. Over the long term, this could lead to standards that would allow companies to understand where to invest to advance their business and promote sustainability for everyone.

Making our economy more circular is a huge, complex challenge. But it’s exciting to look to nature for inspiration on how we can keep materials in use indefinitely—benefiting both people and the planet. 

Published Nov. 13, 2024, by NIST.