Latest / The Manufacturing Podcast with Fexingo: Factories, Supply Chains, and Industrial Business / How a Scottish Factory Turns Whisky Waste into Green Hydrogen
Transcript
- Lucas: So, you know how a whiskey distillery produces a ton of waste? I'm talking about draff — that's the spent grain — and pot ale, the leftover liquid after distillation. Luna: Right, and traditionally that stuff gets turned into animal feed or dumped into the sea. But I've heard there's a project in Scotland turning it into something much more interesting. Lucas: Exactly. There's a distillery in the Speyside region — I won't name it because the project is still scaling — that's partnered with the University of Aberdeen to produce green hydrogen from those waste streams. Luna: Green hydrogen? So they're using renewable energy to split water, but with a twist? Lucas: Right. The process starts with anaerobic digestion. The draff and pot ale go into a digester, where microbes break them down and produce biogas — mostly methane and carbon dioxide. Lucas: Then they run that biogas through a steam methane reformer to produce hydrogen. And because the biogas is renewable, the hydrogen qualifies as green. The pilot plant is producing about 200 kilograms of hydrogen per day. Luna: Two hundred kilos — what does that actually power? That's not a lot in energy terms, is it? Lucas: It's enough to fuel about 20 hydrogen fuel-cell delivery trucks per day, assuming each truck needs around 10 kilograms for a full day's route. The distillery is piloting it with their own logistics fleet. Luna: So they're essentially closing the loop: waste from making whisky becomes fuel to deliver the whisky. That's a nice narrative. Lucas: The economics are still early. Producing green hydrogen this way costs around $6 per kilogram right now, compared to about $2 for hydrogen from natural gas. But the waste feedstock is essentially free, and they're getting government grants from the Scottish Hydrogen Innovation Fund. Lucas: The real breakthrough will be if they can get the cost down to $3 per kilogram. At that point, it becomes competitive with diesel on a per-mile basis when you factor in maintenance and carbon taxes. Luna: What about scale? How many distilleries could do this? There are over 140 malt whisky distilleries in Scotland alone. Lucas: The University of Aberdeen study estimates that if all Scottish distilleries adopted this process, they could produce about 10,000 tonnes of green hydrogen per year. That's enough to power 1,500 delivery trucks or provide heat for 50,000 homes. Luna: And what about the carbon impact? Are they capturing the CO2 from the biogas too? Lucas: Not yet in this pilot. The CO2 from the reforming process is currently released. But the next phase includes carbon capture. If they add that, the hydrogen could be carbon-negative on a lifecycle basis, because the carbon in the biogas was originally pulled from the atmosphere by the barley. Luna: So you'd be putting carbon back in the ground, essentially. That's compelling. Lucas: There's also a scalability challenge beyond just the number of distilleries. Each distillery produces a relatively small volume of waste — so you'd need either a modular hydrogen system at each site, or a central processing plant that collects waste from multiple distilleries. Lucas: The project is exploring both. But the modular approach is more likely for now, because it avoids the logistics of hauling wet waste long distances. Luna: What about other industries? Breweries produce similar waste — could this model apply to them too? Lucas: Absolutely. In fact, a brewery in Colorado is already piloting a similar system. Beer production yields spent grain and wastewater that can go through anaerobic digestion. The hydrogen output could power brewery trucks or even the brewing process itself. Lucas: And it's not just beverages — any agro-industrial process with organic waste streams could theoretically work. Cheese whey, olive pomace, coffee pulp. The same technology stack applies. Luna: It feels like we're seeing industrial symbiosis become more practical. The waste from one process becomes the fuel for another. Lucas: That's exactly the term. Industrial symbiosis. The Kalundborg industrial park in Denmark has been doing it for decades — sharing steam, water, and waste between a power plant, a refinery, and a pharmaceutical company. This whisky to hydrogen model is a more modern, more scalable version. Luna: And hydrogen has the advantage of being storable. You can produce it when the distillery is running and use it when needed, unlike electricity from a solar panel. Lucas: That's a key point. Hydrogen is an energy carrier, not just a fuel. You can store it in tanks for weeks, and then use it in a fuel cell or a combustion engine. The pilot project is using compressed hydrogen at 350 bar, typical for heavy-duty trucks. Lucas: Now, the distillery hasn't fully decarbonized its own operations yet — they still use natural gas for the stills. But the hydrogen from waste could eventually displace some of that natural gas, if they install a hydrogen boiler. Luna: So the next step is to use the hydrogen they produce to actually heat the distillation process. That would close the loop even further. Lucas: Exactly, and that's the long-term vision. The project has received about $8 million in funding so far, mostly from the Scottish government and a consortium of distillers. They're aiming for commercial scale by 2028. Luna: I'm curious about the life cycle assessment. Are they measuring the overall carbon footprint of the hydrogen compared to diesel or natural gas? Lucas: They are. The preliminary data shows a 60 to 80 percent reduction in greenhouse gas emissions compared to diesel, depending on how far the hydrogen is transported. If the hydrogen is used onsite, the reduction is closer to 80 percent. Luna: That's significant. And since the feedstock is waste, you're not competing with food crops for land, which is a criticism of some biofuels. Lucas: Right. No land-use change, no fertilizer inputs. The waste is a byproduct that would otherwise cost money to dispose of. So there's a cost saving on the waste management side, too. Luna: Let's talk about the broader hydrogen economy. Is this model a niche or could it really move the needle on hydrogen production globally? Lucas: I think it's a niche, but an important one. Global hydrogen production today is about 100 million tonnes per year, almost all from fossil fuels. waste to hydrogen from distilleries and breweries might add a few hundred thousand tonnes — less than one percent. Lucas: But the real value is proving that decentralized, modular hydrogen production from waste can work economically. That proof of concept could unlock larger-scale projects using agricultural waste, municipal solid waste, or even forestry residues. Luna: Which industries are watching this closely? I imagine logistics companies and food and beverage giants. Lucas: Yes, Diageo, the beverage giant, has its own sustainability targets and is investing in similar projects. Also, companies like Air Liquide and Linde, which produce industrial gases, are interested because it offers a distributed production model that could complement their large central plants. Luna: Speaking of supporting innovation like this, these kinds of deep-dive stories take time to research and produce. If you find value in these conversations, a couple of dollars a month is genuinely what keeps them going — buy me a coffee dot com slash fexingo, if you've gotten something out of them. Lucas: Yeah, it makes a real difference. Every bit helps us keep digging into stories like this one. Luna: So back to the distillery — what's the next milestone? When do we expect to see the first commercial-scale plant? Lucas: The project roadmap shows a full-scale plant producing one tonne of hydrogen per day by 2028. That would be enough to power about 100 trucks daily. If that hits its cost targets, we could see a wave of adoption across the Scotch whisky industry. Luna: And maybe beyond whisky. A toast to that — but I'll stick to the hydrogen, thanks. Lucas: Exactly. Cheers to the circular economy.