Energy

World first: Dutch brewery burns iron as a clean, recyclable fuel

World first: Dutch brewery bur...
A worker pours iron powder into a funnel to feed a furnace. The Bavaria brewery is now the first business in the world to use metal powder as a clean, sustainable fuel for combustion
A worker pours iron powder into a funnel to feed a furnace. The Bavaria brewery is now the first business in the world to use metal powder as a clean, sustainable fuel for combustion
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A worker pours iron powder into a funnel to feed a furnace. The Bavaria brewery is now the first business in the world to use metal powder as a clean, sustainable fuel for combustion
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A worker pours iron powder into a funnel to feed a furnace. The Bavaria brewery is now the first business in the world to use metal powder as a clean, sustainable fuel for combustion
Metals in powdery form can burn very well, releasing a lot of energy without any CO2 emissions and leaving only a recyclable oxidized by-product
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Metals in powdery form can burn very well, releasing a lot of energy without any CO2 emissions and leaving only a recyclable oxidized by-product
The iron fuel combustion system is delivered to the brewery on a truck
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The iron fuel combustion system is delivered to the brewery on a truck
View gallery - 3 images

Many industries use heat-intensive processes that generally require the burning of fossil fuels, but a surprising green fuel alternative is emerging in the form of metal powders. Ground very fine, cheap iron powder burns readily at high temperatures, releasing energy as it oxidizes in a process that emits no carbon and produces easily collectable rust, or iron oxide, as its only emission.

If burning metal powder as fuel sounds strange, the next part of the process will be even more surprising. That rust can be regenerated straight back into iron powder with the application of electricity, and if you do this using solar, wind or other zero-carbon power generation systems, you end up with a totally carbon-free cycle. The iron acts as a kind of clean battery for combustion processes, charging up via one of a number of means including electrolysis, and discharging in flames and heat.

Recently, Swinkels Family Brewers in the Netherlands has become the first business in the world to put this process to work at an industrial scale. The company has been working with the Metal Power Consortium and researchers at TU Eindhoven to install a cyclical iron fuel system at its Brewery Bavaria that's capable of providing all the heat necessary for some 15 million glasses of beer a year.

“We are enormously proud to be the first company to test this new fuel on an industrial scale in order to help accelerate the energy transition,” said Peer Swinkels, CEO of Royal Swinkels Family Brewers. “As a family business, we invest in a sustainable and circular economy because we think in terms of generations, not years. We combine this way of thinking with high-quality knowledge in the collaboration with the Metal Power Consortium. Through this innovative technology, we want to make our brewing process less dependent on fossil fuels. We will continue to invest in this innovation.”

The iron fuel combustion system is delivered to the brewery on a truck
The iron fuel combustion system is delivered to the brewery on a truck

As a burnable clean energy storage medium, iron powder's advantages include the fact that it's cheap and abundant, the fact that it's easy to transport and has a good energy density, its high burning temperature of up to 1,800 °C (3,272 °F), and the fact that (unlike hydrogen, for example) it doesn't need to be cryogenically cooled, or lose any energy during long periods of storage.

The round-trip energy cycle efficiency of this system is dependent on the processes used to put the energy into the iron in the regeneration process. High-efficiency electrolysis of iron oxide can store as much as 80 percent of your input energy in the iron fuel, according to this 2018 paper – a figure similar to what you get with modern hydrogen splitting.

There are bigger plans for this technology than just firing up individual industrial applications – or even just applications where the main output is heat.

“While we’re proud of this huge milestone, we also look at the future,” says Chan Botter, who leads student team SOLID at TU Eindhoven, a group dedicated to the advancement of metal fuels. “There’s already a follow-up project which aims to realize a 1-MW system in which we also work on the technical improvement of the system. We’re also making plans for a 10-MW system that should be ready in 2024. Our ambition is to convert the first coal-fired power plants into sustainable iron fuel plants by 2030.”

Metals in powdery form can burn very well, releasing a lot of energy without any CO2 emissions and leaving only a recyclable oxidized by-product
Metals in powdery form can burn very well, releasing a lot of energy without any CO2 emissions and leaving only a recyclable oxidized by-product

Using this kind of cyclical process to generate electricity could approach a theoretical efficiency around 40 percent, again according to this 2018 paper. It might seem a little odd to generate renewable energy, then toss 60 percent of it out in the form of inefficient steam turbine generation processes, but this could end up being a flexible and cost-effective way to capture, distribute and even export renewable energy that's generated at inconvenient times when there's no demand for it to be fed directly into the grid.

Running iron powder through existing power generation infrastructure, which may simply need retro-fitting to deal with a different combustion process, would enable a very clean, yet load-responsive power grid that could operate on an easily-stored stash of raw material trucked in either from clean, renewable energy regeneration operations as described above, or from any number of industrial manufacturing operations.

Economics will eventually determine how far this idea gets, of course, and that remains in question at this early stage. But the idea certainly seems to have some advantages over hydrogen, pumped hydro, batteries or kinetic energy storage, depending on what you're using it for, and it's an interesting idea we'll be keeping an eye on.

See a simple video about the process below.

Iron Powder - the green energy solution

Sources: TU Eindhoven, Swinkels Family Brewers

View gallery - 3 images
26 comments
pete-y
Presume that a wide range of metals can be used in the same way. We all know magnesium burns nicely and the navy can tell you about burning aluminium. As they can be re-used the value of the metal is not critical. So the nub point will be which metal can be recycled and burned with the highest efficiency ?
Hellem
Yes interesting idea but science without number is not science. Without the TU Eindhoven team can quantify the efficiency (energy produced/energie (renewable) input )it cannot be compared with other "high density storage" methods such as hydrogen. Hydrogen fuel cell is under 70% and modern batteries are over 85% when assuming renewable generation. Numbers please someone?
martinwinlow
"It might seem a little odd"... bl**dy stupid would be my thoughts; like using renewable energy (or any energy, for that matter) to harness hydrogen in the same way. Just put it in a battery, FCOL! No need to re-invent the wheel (and waste $$$/€€€ in the process) and 90% efficiency. Utterly bonkers! And no mention of the energy (probably electrical... and I'm guessing *a lot*) used to grind the iron to a power in the first place. It won't do it itself! Whilst I'm in rant-mode, I can't help thinking a bucketful of iron powder at a time won't get them very far, either...!
GeoffreyR.Gunning
But wait ...... the iron oxide requires more energy to reduce it back to iron metal than it's oxidation yielded in it's burning. (That's elementary thermodynamics). And using electricity to do it by electricity makes no sense. You would be better off just using the electricity to heat your process in the first place. Am I missing something?
guzmanchinky
What an interesting idea! And far more usable than batteries, which have dirty manufacturing processes and fall apart eventually.
paul314
What temperature does the iron burn at? Does that have implications for the efficiency of the steam production? Also, it does seem that a lot of what people are talking about for green energy innovation is not so much the generation but the issues of moving energy from place to place.
1stClassOPP
What’s required for the ignition? Will a lit match ignite the iron powder? Will the iron powder sustain ignition, or do you need a constant heat source to maintain combustion? Lots of questions. I don’t think we’re getting the whole story here.
Expanded Viewpoint
Exactly correct, GRG!! It seems like we have a never ending parade of idiots coming up with totally stupid ideas on how to "save the environment" by one bogus scheme or another! When I see words like "theoretical" or "might", "maybe", "perhaps" or some other vagueness being used to sell me on some point, I instantly smell the stink of it. How much energy is involved if getting the Iron in the first place? It doesn't grow on trees, and even if it did, it would still have to be processed into a usable form. Is just plain air being used to oxidize it into rust? Our air is only about 21% Oxygen, the rest is Nitrogen and a handful of other gasses, so to get the thermal efficiency up we need to use pure Oxygen, and how do we get that, outside of using a very expensive process?
There are NO perfectly closed loop systems, that I know of. If someone can point one out to me, I'd love to know what it is! And if this system was perfectly closed, then there would be no need for it, because you wouldn't be getting anything out of it! They should just use the electricity coming from their solar panels or such directly, and forget about all of the rest. Just think of all the money they would save by being smart, instead of stupid!!
Nissi
Someone who knows chemistry better than I - Would it be feasible to add aluminum to the iron oxide to make thermite for a second exothermic reaction (thus turning the iron oxide back to elemental iron for the next burn) and selling off the aluminum oxide product to the many industries that need/use it? This would be instead of burning solar/wind energy on reversing the oxidization of the iron. If that is stupid, please tell me why - I want to learn.
MemoriaTechnica
Sounds interesting, however, iron is already a pretty high demand material, just how much would it take to meet demands? Would we have to start strip mining the crap out of places and removing whole mountains? And when they say it's recyclable, what percentage comes out after burning? i.e. is there 10% left over, 40%?? And what about initial processing to get it into a burnable state? That sounds rather energy intensive. Are there any issues with impurities? i.e. Either having to remove them before hand and or if some gets burned? Somehow this feels like an idea the coal and mining industries would come up with. When factoring *everything* in, end to end, what is they total cost and environmental impact with large scale implementation?