Latest / The Manufacturing Podcast with Fexingo: Factories, Supply Chains, and Industrial Business / How a Danish Factory Is Making Sugar from Straw
Transcript
- Lucas: So I was reading about this factory in Kalundborg, Denmark, that's figured out how to turn straw into sugar. Not the kind you put in your coffee — but a fermentable sugar that can be used to make biofuels, bioplastics, even some pharmaceuticals. Luna: Straw as in the leftover stalks from wheat and barley? That's a lot of dry, woody material. How do you get sugar out of that? Lucas: That's the million-dollar question, and it's been the challenge for decades. The plant uses a mix of enzymes to break down the cellulose and hemicellulose into simple sugars. The technology has existed in labs, but the tricky part has always been doing it cheaply enough to compete with corn or cane sugar. Lucas: What's interesting is that they've apparently got the cost down by about 40 percent since 2022. That's a huge swing. It means they're getting close to the point where cellulosic sugar could actually replace traditional sugar as a feedstock in some industrial processes. Luna: So what's the secret? Is it the enzyme mix, or the way they run the plant, or something else? Lucas: A big part is the enzyme cocktail. Novozymes supplies the enzymes, and they've been tweaking the formula for years. But it's also about the plant design. They're not just running a standalone factory — they're integrated into the Kalundborg industrial park, so they can use waste heat and energy from a neighboring biomass power plant. That cuts their energy costs dramatically. Luna: So it's a circular economy play. The straw comes from local farms, the sugar goes to bioplastics or biofuel, and the plant itself runs on renewable energy. Sounds almost too good. Lucas: Well, there are still big hurdles. The plant is a demonstration facility, not a full commercial plant. The cost per ton is still higher than conventional sugar, but it's getting close. And the investment needed to scale up is substantial. That's what we're really talking about today — the business of making clean materials cheaper. Luna: Right, because if this gets cheap enough, it's not just about a niche product. It's about the entire supply chain for chemicals, plastics, and fuels. Lucas: Exactly. Let's start with what the plant actually produces. They call it cellulosic sugar, and it's really a syrup with fermentable sugars. The process starts with straw that's harvested after the grain is removed. The straw is chopped, pre-treated with steam and mild acids to break down the lignin, and then the enzymes do their work. Lucas: The result is a sugar solution that can be fermented by yeast or bacteria to make ethanol, or used as a building block for things like lactic acid, which goes into biodegradable plastics. Luna: And what about the economics? You said the cost is down 40 percent. What's the price today, roughly? Lucas: I've seen figures around 40 to 50 cents per pound, depending on the source and how you account for energy and capital. That's still above the world price of sugar, which has been around 20 to 25 cents for a while. But corn sugar, like high-fructose corn syrup, is also in that range. So they're getting competitive for industrial uses. Luna: So what's the catalyst for the cost drop? Is it just scale, or are they doing something really different? Lucas: A lot of it is the enzyme efficiency. Novozymes has been able to reduce the amount of enzyme needed per ton of straw. That's a big cost driver. Also, they've improved the pre-treatment process to get more sugar out of the same amount of straw. And the plant has become more energy-efficient by integrating with the industrial park's grid. Luna: It's like they're wringing every bit of efficiency out of the system. But I imagine there are skeptics who say this only works in a specific Danish setup. Lucas: That's a fair point. The Kalundborg plant benefits from Denmark's district heating and a strong industrial symbiosis. But the core process could be replicated. There are similar efforts in the U.S. and Brazil. The U.S. has some cellulosic ethanol plants that struggled, but they used different pre-treatment and enzyme approaches. Lucas: Brazil is interesting because they have sugarcane straw, which is a bit different. But the Danish model is notable because they've shown that it can work in a cold climate with wheat and barley straw. Luna: So if this scales, what would it mean for the average consumer? I mean, we're not going to see straw sugar in our soda anytime soon, right? Lucas: Probably not directly. But it could mean cheaper bioplastics, which would show up in packaging, car parts, even textiles. And it could make biofuels more viable, which might have a subtle effect on fuel prices. More importantly, it gives companies an alternative to fossil-based feedstocks, which could help stabilize supply chains. Luna: And that's a big deal for manufacturers who are under pressure to decarbonize. If they can source a renewable chemical that's close in price, they can actually meet their sustainability goals without a huge cost hit. Lucas: Right. And that's what makes this worth watching. The technology has been promising for years, but the cost curve is finally moving. If this Danish plant can prove it at a commercial scale, it could open the door to a whole new bioeconomy. Luna: One thing that strikes me is that this is a classic example of how government policy and industrial clustering can accelerate innovation. Denmark has been very supportive of green tech, and Kalundborg is a real world model. Lucas: Absolutely. They have a carbon tax and a lot of investment in bio-based industries. That creates a favorable environment for these projects. But it's not just policy — it's also the fact that the companies there are willing to collaborate. The industrial park is famous for sharing energy, water, and materials across different plants. Luna: So what's the next milestone? When could we see a full-scale plant? Lucas: The current plant is a demonstration unit that's been running for a few years. The next step would be a commercial plant, maybe twice the size. I've heard they're looking at a capacity of around 50,000 tons of straw per year, which would produce maybe 20,000 tons of sugar. That's still small compared to the world's sugar production, but it would be enough to supply a few big chemical plants. Luna: And who's the customer? I mean, who buys this sugar? Lucas: The main customers are companies that make bioplastics, like the ones producing PHA or PLA. They need a consistent supply of fermentable sugar. There's also interest from the pharmaceutical industry, which needs sugar for some fermentation processes. And of course, there's potential in the biofuel sector, though that's more price-sensitive. Luna: It sounds like the demand is there, but it's a chicken and egg problem. They need scale to lower costs, but they need orders to justify scale. Lucas: Exactly. And that's where some of the larger chemical companies come in. They've made commitments to reduce their carbon footprint, so they're willing to sign long-term offtake agreements at a slight premium to green chemistry. That gives the factory the revenue certainty to expand. Luna: Speaking of revenue certainty — I know we've talked about this before, but it's worth reminding our listeners that these kinds of in-depth conversations are possible because of the people who support us through buy me a coffee dot com slash fexingo. It's a small group, but it covers the editing and hosting costs, and it keeps this show free of ads. Lucas: Yeah, it's a real help. And it means we can dig into stories like this without worrying about sponsors. So if you find value in what we do, that's where you can chip in. But now, let's get back to the straw. Lucas: Another angle is the competition. There are companies in other countries trying similar things, but the Danes have a head start because of the industrial symbiosis. The question is whether they can keep that advantage as the technology spreads. Luna: I read that the farmers are actually getting a new revenue stream from selling their straw. That's got to be a win-win for rural communities. Lucas: It is. The plant pays farmers for the straw, which they used to just leave in the field or burn. It's not a huge amount per farm, but it adds up. And it's a way to diversify income. Of course, there are concerns about soil health if you remove too much straw, so they have to be careful about how much they take. Luna: So it's not a silver bullet. There are trade-offs. Lucas: Right. But the Danish approach is to leave some straw on the field for soil organic matter. They've done studies on this, and they've found a balance. It's a reminder that this is a complex system. Luna: What about the environmental footprint of the plant itself? I assume it's not zero. Lucas: It's not, but it's significantly lower than traditional sugar from cane or beets. They use renewable electricity, and they capture some of the CO2 from fermentation, which can be used in other processes. The net impact is far less than fossil-based alternatives. Lucas: But the real test will be when they start building bigger plants. The capital costs are high, and there's always risk that the economics don't scale the way they do in a demo. Luna: What would a commercial plant like that cost? I'd imagine hundreds of millions of dollars. Lucas: Yeah, I've seen estimates of anywhere from 200 to 400 million dollars, depending on capacity and location. That's a serious investment. But if they can secure financing and offtake agreements, it could happen within a few years. Luna: So how close are we to this becoming mainstream? Lucas: I'd say we're at a tipping point. The technology is proven, the cost is getting close, and there's policy support. But it still needs a few bold companies to commit to the first commercial plants. Once we see one or two of those, it could snowball. Lucas: For our listeners who are in manufacturing or supply chain, this is worth keeping an eye on. If cellulosic sugar becomes a commodity, it could change the feedstock economics for a lot of products we use every day. Luna: And if you're a farmer, it might be a new revenue stream. If you're a chemical company, it's a way to green your supply chain. It's a good example of how innovation happens at the intersection of biology and engineering. Lucas: Exactly. So the next time you see a plastic bottle that says 'plant-based,' it might not come from corn or cane. It might come from straw. And that's a story we'll be following closely.