Guest Columns

Dairy Research

How can U.S. dairy participate in the new circular bioeconomy?

John Lucey

John Lucey, director of the Wisconsin Center for Dairy Research and professor of food science at the University of Wisconsin-Madison, contributes this column for Cheese Market News®.

Major industries in the U.S. are looking at how they can operate more efficiently, reduce greenhouse gas emissions and ultimately move toward net zero (where greenhouse gases going into the atmosphere are balanced by their removal by forest, oceans, soil, etc.). This will require a major transformation of our economy.

The dairy farming sector is actively engaged in this effort and is exploring approaches to reduce methane emissions from enteric and manure sources as well as better soil management practices. I think an important question is what can we — the dairy processing industry — do to also reduce our environmental impact? Many of our dairy plants have already taken positive steps in this direction but, as an industry, I think that we have the potential to do much more.

To start with, we can look at practical strategies at our dairy plants, such as using renewable energy sources like solar or biogas generated from waste treatment. Heat recovery systems like heat pumps can help reduce energy costs. Another aspect is the use of recyclable packaging. A lot of retail cheese packaging is single use and goes into the garbage. Various food and consumer packaged goods companies are also looking at switching to recyclable or compostable materials.

Dairy plants should also be looking closely at their mechanical systems and monitoring and measuring the amount of energy, water, etc. that the plant uses. This would allow you to understand exactly how much plants use and would help in setting energy or water usage goals as a step in reducing future use.

There is another, exciting side to this discussion that is new to our dairy industry, and that is the concept of decarbonization. Decarbonization is moving to an economic system where carbon production/utilization is, essentially, a closed loop. Currently, we are in a linear system where we are extracting new (or trapped) carbon (e.g., fossil fuel) from the ground and then using it and releasing it into the atmosphere. The continuous release of additional carbon (like carbon dioxide or methane) into the atmosphere is contributing to global warming. Decarbonization is moving toward a circular bioeconomy where we are generating enough carbon from biomass, using it to create the necessary chemicals and fuels that our society needs and then recycling or reusing this carbon over and over again.

The dairy and agriculture sectors are well suited to participate in this decarbonization effort since they both produce a lot of byproducts. Instead of disposing of these byproducts, they could be used for microbial fermentation or bioconversion into valuable chemicals and chemical precursors that could replace fossil fuel derived materials. Our dairy industry has no shortage of byproducts, and the volumes are growing. The U.S. produces about 1.12 billion pounds of cheese, which results in about 10 billion pounds of liquid whey. The U.S. also annually produces about 30 million metric tons of ultrafiltered milk permeates and about 2 million metric tons of acid whey from Greek yogurt products as well as cream cheese and cottage cheese. These dairy streams are rich in a simple sugar, lactose, and are renewable organic sources. We also spend a lot of money building and operating waste treatment plants, which do not provide any return in most dairy factories.

In other words, there is tremendous opportunity for the dairy processing industry to be a source of renewable feedstocks for this new bioeconomy. Currently used feedstocks for biofermentation processes include corn and cane sugar, but both are also key sources of human food, and going forward, there are concerns with using food materials for the new bioeconomy as we actually need more food to feed the growing global population. Whey permeate is a good example as a likely dairy feedstock. Our industry produces around 600,000 tons of dry permeate powder every year, and there is very marginal value in it (and drying is very energy intensive). It is mostly used in animal feed. We need to find some better uses for it. Of course, there would need to be a significant amount of research, but I think it is possible, and the exciting thing is that work has already started.

So, how could the dairy industry play a role in this circular bioeconomy/decarbonization? We have some big ideas that could become practical options through research and innovation.

• Producing bioplastics from dairy byproducts — It is possible to utilize dairy byproducts like whey as feedstocks for bioengineered bacteria that can ferment these byproducts into materials used to make biodegradable plastics. Currently only about 1% of plastics are bioplastics. The rest are derived from fossil-based chemicals. It is estimated that by 2030 U.S. plastic industry’s contribution to climate change will equal the contribution from coal-fired power plants.

• Making biofuels/biogas — There is an opportunity to establish biorefineries to produce various chemicals and then utilize any remaining residues in biodigesters to produce biofuels or biogases. For example, it would be possible to use an approach like this to heat water in dairy plants.

• Using dairy byproducts to produce renewable green chemicals (e.g., medium chain fatty acids, organic acids, platform chemicals, etc) — Fossil fuels are currently used to provide the carbon building blocks for essentially the entire chemical industry in the U.S. (> 90% of chemicals are currently fossil derived). With research and development, it may be possible to use dairy byproducts to generate renewable green chemicals versus traditional hydrocarbon-based chemicals.

• Improved soil and water health — If we effectively use these strategies, we would reduce the amount of agricultural waste that is currently spread on land or going into landfills. Both of those routes negatively impact the health of our soil and water. Minimizing runoff lessens the potential environmental impacts due to leaching of nitrogen, phosphate and other materials into the soil, ground water or atmosphere.

• Utilizing food waste — Currently, about one-third of dairy products end up as food waste (e.g., milk that is past its use-by date, etc.) in landfills. Landfills contribute about 17% of annual methane emissions in the U.S. If we take that food waste and utilize it for a biofermentation process, we reduce the amount of waste that goes into our landfills and thus help reduce greenhouse gas emissions.

These are all tremendous opportunities to help our dairy industry achieve net zero and participate in the circular bioeconomy. I believe there is a lot of potential in these projects to produce real world, cost effective results.

However, to achieve this, we will need a lot of research, industry support and new technologies. We would need to engineer microbes to produce these various chemicals, develop reactor conditions to perform these fermentations, then isolate or purify the target chemicals, scaling up these processes and along the way doing a technoeconomic analysis to understand if the new bio-approach is cost competitive compared to the traditional processes.

There’s a lot of work to be done, but we need to get started. Other sectors are already looking at how they can participate in decarbonization and providing renewable feedstocks for the bioeconomy. Going forward, our industry can help feed the world and help save the planet.


The views expressed by CMN’s guest columnists are their own opinions and do not necessarily reflect those of Cheese Market News®.

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