I've been intrigued for a while about various modified wood technologies (eg hardened wood, transparent wood), but I'm always disappointed because it usually ends up just being a minor support structure for a very non-wood material (generally epoxy). This one shows a compression step, so maybe it's different, but I'd really like more info on whether this is actually renewable or sustainable in any interesting sense.
Very reminiscent of the supposedly renewable & sustainable bamboo products that are anything but. I love bamboo, but flooring should make you think "plywood" not "waving groves of fast-growing giant grasses". It's another glue and epoxy thing.
Curious about your opinion on bamboo products. I assume you're referring to modern bamboo desks, shelves, and other items that are made from Chinese bamboo and made in China. They typically slice the bamboo grass pieces into ~8 sections, then use planing machines to create planks※. These are then pressed and glued together to make products. These products are then shipped overseas using the same methods as other products.
If the glue used is either sustainable or they don't use very much of it, and the bamboo is grown locally, what makes it less sustainable than using wood? And certainly more less energy-intensive than steel.
Some good photos of the process here[1]. The figure that's generally quoted for the time it takes for a mature timber bamboo culm to grow from a shoot to ~20m to be harvested is 3-5yr. Obviously each one is small compared to a large tree, but a stand of bamboo can produce a lot.
The usual complaint I see against bamboo products is that they use hard bamboo that grows like trees, but promote a sustainable image based on the idea of soft bamboo that grows like grass. I haven't heard it's less sustainable than wood, just not any more sustainable.
It takes 4-5 years to grow according to the article, and you can make Strand Woven Bamboo out of it. You can get a feel for the hardness of Strand Woven Bamboo here:
"Even though a Janka rating of 8 is considered ‘hard’,
many Australian timber species achieve ratings of 12
and above."
Strand Woven Bamboo has a Janka rating of 14.
As it happens I live in Australia, and so have tried to bang the odd nail into an old house, which are often made from Australian hardwood. Almost all of us live in new houses made from pine, and so all make the same mistake. If you are lucky, and after more than a few bent nails, some old codger will take pity on you and tell you it isn't possible. You have to pre-drill.
Different species. Bamboo is actually a family of 1,400 individual species, not one individual plant. The grassy and woody varieties are just different plants with different material properties.
As a general rule, the structural properties of wood can’t really be changed without just injecting a shit load of petroleum products[0], which isn’t really what we’re after here. If a type of wood, bamboo or otherwise is too soft for an application, then there really isn’t a way to “harden” it. This is the reason we tend to use hard species for flooring, such as oak, as you need to rely on the natural characteristics of the wood for strength and hardness.
0 - For example OSB, which is basically 5% oil by weight. Even still, our ability to adjust some properties is limited. OSB is strong and cheap, but it’s not that much harder than the wood species it was made from, and hardness is a desirable property for flooring to resist dents. Also, OSB is ugly.
I'd be very surprised if animal glue was used in any engineered wood. Even in fine woodworking it's a niche product; it's expensive and generally doesn't work as well as other glues.
"The significant disadvantages of hide glue – its thermal limitations, short open time, poor gap filling capability and vulnerability to micro-organisms – are offset by several advantages. Hide glue joints are reversible and repairable. Recently glued joints will release easily with the application of heat and steam. Hide glue sticks to itself, so the repairer can apply new hide glue to the joint and reclamp it. In contrast, PVA glues do not adhere to themselves once they are cured, so a successful repair requires removal of the old glue first – which usually requires removing some of the material being glued."
> After the material is processed and carved into the desired shape, it is coated in *mineral oil* to extend its lifetime.
I was thinking how, surely, mineral oil isn't food-safe and well-fit for use on a utensil. However, it turns out that while low-grade mineral oil is proved carcinogenic, the high-grade version is not believed to be so, unless dispersed in a mist. And apparently, we consume quite a bit of mineral oil due to it's use in the baking industry (though that figure comes from 1961)
Mineral oil can be found in most pharmacies marketed as a laxative. It's a common oil to use for cutting boards and other applications in proximity to food.
Right, another instance of where the mineral product is to be much preferred over the so-called natural one is with turpentine.
Mineral turpentine is to be much preferred over the natural one because the latter contains organic wood terpenes many if which are toxic and proven carcinogens - after all it stands to reason that they're dangerous, as trees have evolved to produce them to fend off or poison insects that attack them.
I find it somewhat distressing to see so many carpenters and woodworkers using terpenes-laced turpentine because they believe 'natural' is better.
It depends on what you mean by mineral oil. Without definition it's about as useless as saying I've painted something in 'color' rather than specifying what color one used.
Whilst flammable, and for the simplest ones, even explosive - most small straight-chained alkanes as often found in mineral oils are reasonably innocuous in that they're not considered organically poisonous (at least in small amounts), however that can change greatly the moment you add certain additives to change their properties (as is often done in commercial products).
The most notorious and outrageous example being when Thomas Midgley Jr added tetraethyllead to gasoline/petroleum in the 1920s thus managing to poison most of the population to at least some extent.
Since the article talks a lot about replacing small plastic utensils, it seems plausible that they're not targeting structural applications at the moment, so the point about glue could be moot.
Reminds me of the one video I saw of this man spraying different things with some sort of polymer that was virtually unbreakable. He'd spray a cinderblock wall and then hit it with a sledgehammer. The wall would break, but the polymer would hold... so yay?
That said, It seems like the sort of thing you'd want to spray asphalt shingles with.
Well it didn’t involve any epoxy, just a chemical bath in readily available chemicals and a pressure step. The energy requirements seem significantly lower than steel processing.
Mechanical engineer here. This article is very light on a lot of detail which would allow you to reasonably compare this material to steel, plastic or any other material. Just a few that come to mind:
Hard materials are usually brittle materials that fail suddenly. How tough is it? ie. Can it accept some deformation without significant weakening and will it stretch or crack prior to failure?
What is its compressive strength? What is it's tensile strength? Could it be used to reinforce concrete? Pipe liquids or gases? Does it's strength drop when it gets wet?
How dense is it? How flammable is it? How easy is it to machine without damaging it?
And of course the big one - how much does it cost?
Wood is renewable when you can grow it, cut it up into useful shapes, then at the end of its useful life, compost it. As soon as you add a shit load of processing and plastic and other stuff it's not "wood" anymore than gasoline is a dead dinosaur. As for things like plywood that use glue for the laminations...glue is the most expensive and important part of the product. Not the wood so much. Replacing steel? I don't think so. Yes, steel is a dirty thing ecologically... but steel things last a long time... and require, in general minimal processing...unlike this hardened wood proposal. If steel showed up today as a new material, it would be lauded for all its technical properties. But it is now old and not so sexy.
In addition progress making steel with a lot less CO2, by using hydrogen (and other techniques) instead of coal has come a long way. This isn't just pie in the sky, the world's second largest steel maker plans to reduce CO2 by 30% before 2030. [1] And of course steel is eminently recyclable. I'm not against wood but steel has some good long term attributes as well.
How do they make hydrogen clean? 95% of hydrogen comes from burning fossil fuels. I doubt they're going through electrolysis to make the hydrogen or sourcing it from a supplier that does.
It's part of the ongoing process, we can't skip to the final step. I think it is fair to rely on electricity and assume it will at least one day be green when thinking about green processes in totality, since some places are already generating green electricity. In my city we have a hydrogen plant powered mostly y solar that is feeding the steel mill, and this is just the beginning of exploring this process so it is bound to get more efficient.
Reusing plastics is honestly one of those "do we need to" things these days. The theory is that if we reuse them, then the waste doesn't pollute the environment - but landfilled plastic waste is basically sequestered carbon, and plastic pollution is ocean-borne and mostly being directly produced by poor environmental practice - not unrecycled plastic waste or landfill escape.
Yeah I agree, I'm pretty pro, bury plastic in the ground, but I figure if we need to coke steel rather than digging up coal we can just divert a few trucks.
Yeah seriously, bury the plastic really deep away from water tables and forget about it. We clearly can’t recycle most of the stuff. Couple that with moving away from a frivolous use of plastic and I think we are golden. There are a bunch of abandoned mines miles away from substantial water tables. Fill those up.
We can’t figure out how to store a minimal quantity of radioactive waste in a purpose-built salt mine dozens of miles away from any small town. I have no faith that we can find places to store megatons of plastic waste.
Steel production is one of the largest contributors to global C02 emissions. Reducing it by 30% isn't a solution. Unfortunately, zero-carbon-emissions steel is still not feasibile, which is a major, major issue for the health of our planet.
Yes -- but it's not a start unless we're making zero-emissions steel possible. Otherwise, it's just more of the same. (Akin to stabbing someone with a 30% smaller knife.)
A benefit of using wood is not composting it in the end. We want to pull carbon out of the air, which trees are good at, but we don't want to let it back into the air when it is done. Adding all the stuff to it increases the longevity, which is helpful.
Steel doesn't pull carbon out of the air, unfortunately.
If half of the material ending up as "wood" in a building is epoxy or some other treatment, though, the efficacy of using buildings for carbon capture seems quite decreased.
Not if there is more than a doubling in use of wood. The epoxy, or whatever, makes wood a more compelling construction material, and if it results in far more wood construction, it is a net win.
Why are people not considering just growing large trees to capture carbon cut down those trees and just coat them in plastic and throw them at the bottom of ocean/desert or some kind of storage where this carbon can stay trapped for thousands of years ? What am I missing ?
I think growing trees is better than just capturing CO2 directly as growing a large forest might have other advantages and a lot of wood can be used for normal human industry as well.
The amount of effort required for 10 million trees a day would require everyone in the US to plant a tree each month. This would likely also require people to care for enough saplings to plant a new tree each month.
It's not an insurmountable level of effort per person, but if you try to do it on a large scale you inevitably end up with logistical problems, and it would require quite a lot of space.
I am not sure I understand your math here. Let’s say every adult in the US, 300M, plants a tree each month for 12 months, 3.6B trees planted in a year. Or are you factoring in saplings that fail to grow or something? Is it that bad that for every 160 trees planted only one survives?
Edit: strike that I see what you meant there with the a day. I just should have actually read what you wrote before I commented.
I did some quick googling and the first figure I found was that Americans plant around 1.6 billion trees every year. That is around 4.4 million every day, almost half of what is required for the carbon offset claims by GP.
Actually 20 million trees every 2 days doesn’t sound that ridiculous. Especially as we build more green infrastructure and reduce the daily emissions.
Seaweed is great - it also pulls excess nitrogen out of the water, can be co-cropped with bivalves, can be fed to cows for decreased methane production, can be eaten directly in many forms…
If we had an actual price on carbon seaweed production would be a boom industry.
Couldn't you use it in large tanks to suck out CO² directly from the air? What makes this more expensive than currently proposed alternatives? Even if you don't use the seaweed in the end, you could just dry and bury it I guess?
I'll never understand why it's always "stop climate change" or "deny climate change" but there's essentially no room for "fix climate change" or "reverse climate change". The resources are allocated for polarization and not pragmatism.
I don't think that the economy of wood is worse in the long run. It is quite much faster and cheaper to build with, and as long as it isn't allowed to be wet for long periods of time it also lasts indefinitely (there are wooden temples that are 1300 years old), and repairs are usually faster and easier than similar in concrete.
I'm not sure that's a good data point considering there is stone/masonry structures that old or older. Is there evidence that wood infrastructure is cheaper/more durable from a lifecycle perspective? The industry estimate for timber bridges is typically 20 years (although they may be treated to extend the life further) while 75 years or more for steel or concrete bridges. Timber/glulam also tends to deteriorate faster.
"At comparable ages and spans, smaller percentages of prestressed concrete bridges are classified "structurally deficient" than steel or timber bridges."[1]
There’s something to be said for the fact that harvesting wood is much more environmentally friendly than petroleum. At the very least a “wood spill” doesn’t exist as far as I know.
Petroleum is definitely more environmentally friendly than the timber industry. You probably haven't driven around tree farms - monoculture that destroys the environment for hundreds of square miles. Even worse is when they pulp existing forest for things like toilet paper:
That's an article about toilet paper usage, not building material. There's no petroleum toilet paper, by the way.
Wood is biodegradable, renewable, and recyclable. It can be grown and harvested sustainably; I know because I used to work with a guy who made a living off surveying forestry for sustainable timber harvesting.
It causes no environmental issues if left to rot, doesn't have to be disposed of in a particular way.
The vast majority (well over 90%) of plastic is not recycled.
Plastic never goes away. Plastic just breaks down into microparticles that are now so pervasive there's basically no part of the planet that doesn't have microplastics, no animal that doesn't have them in its digestive system. And all the while, it's leeching out toxic chemicals.
Wood itself is sustainable, but in making a choice of building materials, we're also looking for total embedded energy cost and impact of the final product. Traditional buildings from a century ago relied on the harvest of old-growth wood with denser rings than the new sustainable forestry, and they were built with fewer features - when built well they didn't fail, but they weren't targeting high energy performance, climate control, dust and mold resistance, etc. We can't go back - we could lower our standards but the stock of old-growth remains depleted. New wood constructions often use processed and glued timbers because the processed timbers can be lighter(good glue is really strong) and they don't experience nearly as many quality control issues(solid wood tends to warp).
The thing is, once we start looking at wood in detail, it's never just wood. It's wood, plus adhesives, paints, and finish. You can't use just wood because it rots - you at least need to add some pigment to block UV rays and drainage to limit water pooling. Each of those additives are a potential source of VOCs(volatile organic compounds, the term that more accurately describes "chemicals"). And each step taken during processing adds energy cost. Paper and corrugated cardboard are not innocuous - they use one of the higher-energy processes relative to the amount of input material.
When you look at what you can do besides wood, you get similar tradeoffs. Stone is great, but it's still hard to work with directly, hard enough to not scale to our industrial population - as it stands, you need an artisianal economy of stonemasons to make those huge ancient constructions. Concrete has a huge climate footprint and the dust is a major VOC source. Steel is high-energy and not abundant enough to be used everywhere.
Thus, plastics enter as a way of getting some of the qualities we want. Plastics are not all one of a kind and have varying VOC content. We can't afford not to use them to have this population and quality of life, which means we have to study how to use them safely. The microplastic issue is a part of that, but it's oversold as "plastic is scary". Wood smoke is also scary, as anyone who has been around a wildfire will attest.
Curious to see some data on these claims. Yes, glue is often made out of "chemicals" — but plastic also is. Is the total environmental cost of plastic lower than wood? Besides, you're not going to frame a house with plastic: it's steel and concrete, vs wood. AFAIK plastic doesn't enter the equation here.
We ready use plastic in decks. I bet it can be further scaled up. At what cost I have no idea though. But I wouldn't count it out as a primary building material
Few things, maybe the way to farm trees is naive and can be done in better ways. Just entice companies to have different ways of working (even if they raise the price a little afterwards)
Also petroleum being a big factor in CO2 levels it's hard to not put it first isn't it ?
Looking back at Aluminium, it was once very costly - there was no economical way to extract it from clay by traditional metallurgy. When the Hall process of electrolytic extraction from molten salts was invented = huge price decline, and useage. Titanium is in a similar position, fairly common, but hard to extract economically. I hope there is a low cost electrolytic to recover Titanium found some day, as it is a very good material for all manner of uses at a lower price.
https://en.wikipedia.org/wiki/Hall%E2%80%93H%C3%A9roult_proc...
In that it's one electron from it (like Silicon)? Magnesium is 2.2x stronger, 1.08x harder, and 2.05x more costly, 0.65x as thermally conductive and, 0.64x as dense. Think I'm missing your similarity metric
"nl" already brought few points. As a practical test: take a piece made of cast magnesium (alloy) or cast aluminum (alloy). It'd be hard to easily tell each other apart, save for using a weak acid. Their strength is similar (esp. when alloyed, still worse off for the aluminum) but magnesium is non-trivially lighter. Here, a random quote [0]
Magnesium is also better at casting components with thinner walls and tighter tolerances than aluminum. However, even with the many advantages of magnesium, aluminum remains a less expensive alternative for die casting.
Yep I was really pleased to see that ikea has started offering cheap galvanized steel shelves (named “Hyllis”). Glad to have something fully recyclable.
> As for things like plywood that use glue for the laminations...glue is the most expensive and important part of the product
I've been using a lot of MDF lately, and it's interesting to think that it's just sawdust and glue. It makes me wonder: are there other fibers which could be used in a similar process which would yield better materials than MDF?
I have not seen the paper, but the process almost certainly does not use any glue.
It must use wood compression at very high pressures, which collapses the cell walls in the wood and results in a densified high-strength wood.
There have been various methods to make densified wood for structural applications, but I assume that this is an improved process, which makes an even denser and more homogeneous material, which ensures that even blades can be made from it.
Edit: According to Phys.org, the improvement over the previous processes is a treatment in a chemical bath that removes the lignin and other components of the wood, leaving only the cellulose, before the compression.
This removal of the non-cellulose components ensures that the densified wood is harder and with less defects than those made with the older processes.
Yeah, maybe. But you're right, when it comes to metals, steel's vastly most substantial component, iron is about the most abundant metallic element in the universe, so it ain't gonna disappear from our manufacturing materials list anytime soon.
Iron and steels have their obvious problems - rust for instance, bad performance high high temperatures is another and it'd be nice if iron had properties more like say titanium but that's wishful thinking.
Taming iron to behave the way we want it to has always been and still is a major problem. For example, stainless steel is expensive and it's always been a bit of a kludge (the need for hundreds of different varieties of alloys attest to that; same goes for hardness, for instance, the many tool-steel-like alloys that are needed by industry).
If anything, we need considerably more material science research to make iron alloys much better than they are now and thus make them appear very sexy to everyone's eyes.
No expert here but I believe it depends on how it decomposes. If wood rots at the surface, my understanding is more carbon is released into the atmosphere but if it is buried or decomposed using fungi or soil microbes, more carbon is captured into the soil.
Forests have a lot of decaying and decomposing deadfall wood but still seem to be a carbon sink so it may be a layering thing...
Yes, that's why planting trees to offset carbon emissions is not really as good an idea as it seems, trees can live a long time but they're not immortal, and when they die they release their carbon back into the environment.
If you turn what now is barren land or grasslands into a forest, it absorbs CO2 as it grows, and that CO2 stays captured for as long as that land is a forest, it doesn't matter if individual trees die and decompose.
What I like about this idea is it's a way to take carbon out of the air while manufacturing something. We are going to have to deal with carbon no matter what, why not manufacture things with it?
Making steel is how we got here. Europe was decimating her forests for charcoal. England ran out first, then turned to coal, then needed to pump water out of coal mines...
Good reads, if this area interests you, are Fernand Braudel Civilization and Capitalism Vol 1: The Structures of Everyday Life and Vaclav Smil Energy and Civilization: A History.
It has a carbon neutral implementation (grow trees, the burn them) but it also has a carbon positive alternative which I much cheaper (cut down existing forests an go out of business once there's no forests)
How is Plywood and OSB recycled (for the municipalities that do so)? Wouldn't the different types of glue (from different manufacturers or grades) cause problems there? Or is it just used as an industrial fuel where the glue is burned off?
> In reality, their life span is more like 50-100 years, and sometimes less. Building codes and policies generally require buildings to survive for several decades, but deterioration can begin in as little as 10 years.
I think that's only used for structures immersed in seawater.
It's not that we can't design buildings to last longer, it's that you don't want to design a building to last two centuries when you know it's probably going to be torn down in 50 years no matter what shape it's in.
Stainless steel rebar is also used for (not only seaside) bridges etc, but at 10x the cost it's not going to be in ordinary buildings.
If a building is made harder to demolish than its neighbours it's got a better chance to survive. I plan plutonium-core concrete walls for my mausoleum to prevent future generations from interfering with it.
At least this material has a main ingredient that is renewable. No part of steel is renewable right? You can't grow more iron ore (though there is a lot of it lying around).
Also I'm doubting "minimal processing" for steel. You have to dig up the ore with giant machines, transport huge amounts of it by train, smash it with a lot of energy and heavy equipment, melt it with a lot of energy and heavy equipment, etc., etc. This seems like the opposite of minimal?
Wood also requires heavy equipment to cut, mill, process. Not to mention, it needs a heck of a lot of land area. In addition to whatever process is involved in "hardening" this wood.
Plus, steel is entirely recyclable. And it has some natural properties that make is relatively easy to recycle. It can be sorted with magnets, and it has a higher melting point than most impurities.
The ball of iron would be Earth's core, and between the thin crust on which we live and the iron core there is the very thick mantle.
Nevertheless, the mantle is made of a mixture of iron oxides, silicon dioxide and magnesium oxide, with small quantities of the other elements, so under the thin crust, even if there remain thousands of kilometers until the iron ball, there is nonetheless what is essentially a huge amount of iron ore.
On earth it replenishes too via meteorite strikes and by nuclear decay. I'm not sure was decays into iron, but I'm sure it's most things, given its name as the most stable element
> HempWood is priced competitively to similar cuts of black walnut. You can purchase 72" HempWood boards for between $13 and $40 as of the date of publishing. HempWood also sells carving blocks, cabinets, and kits to make your own table. Prices for table kits range from $175 to $300. Jul 5, 2021 […]
> Is Hemp Wood Healthy? Due to its organic roots and soy-based adhesive, hemp wood is naturally non-toxic and doesn't contain VOCs, making it a healthier choice for interior building.
> Hemp wood has also been tested to have a decreased likelihood of warping and twisting. Its design is free of any of the knots common in other hardwoods to reduce wood waste.
FWIU, hempcrete - hemp hurds and sustainable limestone - must be framed; possibly with Hemp Wood, which is stronger than spec lumber of the same dimensions.
FWIU, Hemp batting insulation is soaked in sodium to meet code.
Hopefully the production and distribution processes for these carbon sinks keeps net negative carbon in the black.
The graph in that composite diagram is really bothering me.
Their "hardened wood" product is 23 times harder than "natural" basswood. When dried, basswood (aka lime) is an extremely soft hardwood. It's very popular with novice turners and hand carvers. When green (natural?) you can carve it with a stone.
Species matters. Lignum vitae is 20 times harder than basswood.
Species matters, but so does availability. Lignum vitae is an endangered species, so it's not really a renewable alternative at the scale humanity requires.
fun fact, you can grow Lignum Vitae in SoCal in certain areas, not just in Florida. San Diego would probably grow lignum vitae well because it seems to like the random humid weeks in Los Angeles and just exists for the rest of the year
About a decade ago I ordered some from a nursery in florida, in retrospect I'm not sure that's an ideal thing to do. But I think I did order directly form the nursery so hopefully they were following the regulations, whereas amazon will freely help third parties sell completely illicit plant materials that could bring pests.
I think the point of using basswood as a reference is to demonstrate the effectiveness of the hardening process by using a very soft wood. Separately, basswood is fairly quick growing, making it a decent candidate for commercialization of the whole technology.
It's not cheap though, all the bloody carvers get it. Not that any wood is cheap at the moment.
I think they might have just been highlighting basswood because it's so soft —softer than many softwoods— and so the outcome shows a much bigger improvement.
That was my first thought too - maybe basswood is cheating. It does look though after some research that it seems that the process can be applied to other woods as well, since the process consists essentially of removing the non-cellulose component of the wood (hemicellulose and lignin) with heated chemical solution, then heat-pressing the resulting cellulose-only matter into hard block material.
Naturally, the harder of the hardwoods (IPE, Brazilian Teak, Ebony) are also relatively low-lignin wood types (that also grow relatively slowly, sensitively or in unfavorable geographical regions for logging and transport) and the result of removing the non-lignin would logically yield a lower improvement factor (and possibly take longer).
In general, the difference between softest readily-available lumber (such as basswood/spruce) and hardest (IPE) is about one order of magnitude. The result of this study at 23x means basswood can be made more than twice as hard as the hardest hardwood that is reasonably available. It would likely take a lot of lumber weight input though (explained below).
To your comment: Most common timber/lumber woods (softer: spruce, red pine, fir, chestnut, tamarack/larch and medium: cedar, maple, oak, birch) are rapid-growing and have established forestry industry around them. If you were to take white pine or spruce it should yield similar results to the study since you're basically condensing it to cellulose and they have similar weight densities. You would need to also factor the density of the wood since yield would be ratio of cellulose * weight of the source wood.
Since this is a high-waste process (only 40% of the weight is kept in the final product which is then compressed to the target density of 10000lbf or so) it would probably make most sense when using waste-wood as input (wood chips, sawdust, offcuts, recycled wood) and not on viable timber. This is similar to LVL and OSB (although it uses glue for binder)
Some composition comparisons:
Nordic Spruce: 39.5% Cellulose [1], 0.43 kg/m3 [5] (the poster child for engineered lumber construction in europe)
To add more huge timber structures to the list, here’s a starting point to see/learn more about the historical Kennecott mine in Wrangell-St. Elias Nat’l park in Alaska [0]. I’ve had the good fortune to walk through it–it is simply incredible.
Can't read the article.
How energy efficient and environmentally friendly is the hardening process compared to making steel? And is it a "in 20 years" thing again, like all new battery tech?
Steel is incredibly energy intensive. It's not unusual for casting plants to have their own dedicated power stations. Traditionally you'd use coke to melt things (well, smelt iron ore), nowadays with induction/arc furnaces you can in theory use green energy, but it's still a huge amount of power.
A general note: in a world of super cheap solar or wind, energy efficiency doesn't matter as much. It's cheap because In many instances, the end product is the "battery".
A desalination plant can be run when the sun is out and the end product (clean water) can be stored and used. In this instance, the hardening step stores energy in the final product. Just run that step at the right time.
This kind of thinking is why cryptocurrency miners are setting up shop at substations. They get severely discounted electricity from the utilities, in exchange for ramping up and down their servers to keep the grid load balanced.
Except, of course, cryptocurrency isn't nearly as useful as, say, desalinated water.
> Except, of course, cryptocurrency isn't nearly as useful as, say, desalinated water.
I'd like to expand on this a bit.
The major problem with cryptocurrency is that the value of a typical coin seems to be ~ the cost of electricity needed to mine one.
This means that a crypto miner turns $1 of energy into ~$1 of wealth.
As far as business plans go, this is an absolutely horrific use of energy. Nearly no other business produces so little wealth, for such a high energy input.
The economy in general, by the way, turns $1 of energy into ~$17 of wealth. [1]
That's why they are pursuing deals with electric companies. In exchange for helping with loaf balancing, they get electricity well below market rates. They are making a killing.
Everyone who buys the coins are just helping to remove the pandemic stimulus from the economy, which I suppose is its own sort of good.
That's a common misconception; energy will matter anyhow.
It's useful to think of industry as a three factor limitation of energy, materials and intelligence[1] -- you are sort of always limited by one of them. If energy was of literal no concern, we could promptly utilize very inefficient carbon capture or even synthesize elements. Solar energy still has significant costs in labor (what I call intelligence) and materials, both of which are finite. We will always as a civilization be managing those factors, even with a seemingly unlimited source like a feasible fusion reactor (which would require an advanced highly costly and finite reactor to produce energy) to solar panels (which outsource the fusion to some 150 million km away producer :) )
A quick googling gives me about 24 MJ/kg for steel production. A compression cycle with, for example, 1cm of displacement would need to exert 2.4 GN or about 24 million tons of kg-force over a 1kg sample to use equivalent energy, which I believe is far above any press in existence.
[1] Indeed we know the first two are equivalent via E=mc^2 , however this conversion constant is essentially prohibitive outside of stellar nucleus. We also know the third one, intelligence, can be built from raw materials and energy, so there's also a conversion factor there.
The summary states the process of making hardened wood is more energy efficient, but I also wonder how long this would take to scale. Seems great for small operations (like the bench at a local park), but might require regulatory changes to use in any large projects.
Not sure if this is exactly the same but cross laminated timber (CLT) is already being used for constructing all kinds of buildings.
Executive summary of its qualities:
- Stronger and lighter than concrete. Think thinner floors and walls but with similar strength and load-bearing capability; less tonnes of material to move around. That alone is a big advantage.
- Several buildings across the world already exist; more are being planned. So, its beyond the proof of concept stage but still early days in terms of adoption.
- A few ambitious skyscrapers are being planned that will be built using it. So, instead of steel and concrete, these would be mostly made out of wood. Needless to say these will be very prestigious buildings; which should count as an advantage as well.
- While it uses glue, it's not nearly as much as e.g. MDF; in the order of a few percent. It's mostly wood basically. The cross lamination is what gives it its strength. E.g. toxicity associated with MDF and similar materials is not much of a concern.
- It's quite safe from e.g. a fire safety point of view and should also be usable in e.g. earthquake zones like Tokyo (which has a 350 CLT building planned). It's also quite durable (e.g. rot & humidity).
- It's a nice way to capture carbon, obviously. As opposed to dumping massive amounts of carbon needed for e.g. concrete production and transport. So, very environmentally friendly. Also after demolition (it's wood basically).
- You can work it using traditional wood working tools. Hammers, nails, saws, etc.
- You can do a lot of this offsite as well and ship prefab components to the construction site. So, there is less waste on site of material that needs to be removed after. Existing construction work involves extensive use of power tools and produces enormous amounts of waste.
- As a side effect of that: faster & more efficient construction. This is a big plus point as construction sites in busy cities are very disruptive.
- Short term its somewhat more expensive than traditional construction methods (concrete). But long term there is plenty of potential for cost reductions due to scaling, learning effects, etc. Large scale CLT production simply does not yet exist.
- The wood needed to produce it could feasibly be produced using sustainable foresting. But obviously that would be a sector that would need to be scaled up. However, if done right, that in itself is a good thing. It would basically mean countries investing in sustainable forestry, which has all sorts of nice side effects in terms of carbon capture, nature, and jobs.
The biggest hurdles are not so much technical feasibility but just changing an industry used to a particular way of working along with its supply chains to work in different ways using different supply chains. That kind of thing does not happen overnight. But with the advantages listed above, there is plenty of interest in this.
> - You can do a lot of this offsite as well and ship prefab components to the construction site. So, there is less waste on site of material that needs to be removed after. Existing construction work involves extensive use of power tools and produces enormous amounts of waste.
Prefab/offsite fabrication can be done with most building types, it's always a tradeoff of many factors: transportation costs generally go up, onsite labor and onsite construction time goes down, offsite labor and construction time becomes a thing, precision usually goes up since the offsite construction is often in a more controlled environment, site specific adjustments can be more difficult depending on the specific methods. If there are standardized pieces, that can reduce overall time to complete a project if there's some amount of warehousing rather than building just in time; offsite construction may also speed up projects when there's more capacity to build components in a factory setting(s) than with onsite labor.
For concrete offsite fabrication, you're looking for words like 'precast' and 'tilt-up'.
HW is something you can do to one piece of wood, while CLT is something you can do to combine multiple pieces of wood. So you could have a HW CLT, for example.
The biggest problem with CLT and other engineered wood beams is that it fails extremely quickly in a fire.
I've heard firefighters talk about how their departments are considering scaling back entries on newer homes because those beams can fail so early in a fire when the binder fails.
A study conducted by two fucking industry trade groups and the USDA Forest Products lab?
> FPInnovations is a private not-for-profit R&D organization that specializes in the creation of solutions that accelerate the growth of the Canadian forest sector and its affiliated industries to enhance their global competitiveness
Did you read the fucking introduction? It's an industry-paid-for shill study:
> Financial support for the development of this US edition of the CLT Handbook was provided by
the Bi-National Softwood Council, US Forest Products Laboratory and Forest Innovation
Investment. Financial support for conducting the fire resistance test series on cross-laminated
timber (CLT) was provided by Natural Resources Canada (NRCan) under the Transformative
Technologies Program, which was created to identify and accelerate the development and
introduction of products such as CLT in North America. FPInnovations expresses its thanks to its industry members Julie Frappier, Eng. from Nordic
Engineered Wood and Andre Morf from Structurlam, Dr. Nourredine Bénichou of the National
Research Council of Canada, NRCan (Canadian Forest Service), the Provinces of British
Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Nova Scotia, New Brunswick,
Newfoundland and Labrador, and the Yukon Territory for their continuing guidance and financial
support.
I guess it must be the steel industry planting astroturfers in reddit comments pretending to be firefighters talking about how they're seeing new construction buildings with engineered structural wood fold stunningly fast, huh?
Don't be a dick. Since you're clearly not going to do your own research and will simply accuse people of disagreeing with you of being industry shills, here are some more articles discussing non-industry studies that show you're full of hot air:
https://blogs.oregonstate.edu/collegeofforestry/2018/03/27/p... (demonstrating that charred CLT can maintain structural integrity at temperatures that could cause steel structures to soften and collapse. Or in other words, that steel structures can be less safe in the event of a fire than a wood structure.
It's not that black and white. CLT is more of a group of materials with different characteristics than a single thing. Fire rated versions of it exist and are commonly used depending on the requirements and building codes. This article has a nice overview: https://constructionexec.com/article/fire-safety-of-clt-and-...
Using cheaper materials for low rise might indeed be an issue. Also, living in houses that are mostly low quality plywood and other flammable materials is of course not great for fire safety. It's a tradeoff between cost, requirements, and regulations.
Even concrete buildings sometimes collapse when fire gets hot enough. Metal loses its strength when it gets warm enough. The collapse of the Twin Towers in New York are a pretty grim example of that.
A blocker to deployment would be getting building codes updated to permit use. From memory, wood was only approved for 3 story or less structures in most of the US. And building codes tend to be updated extremely slowly and conservatively.
When Greta talks to the public sphere about government failing its climate responsibility, this is the kind of stuff she’s talking about.
It’s easy to assume we “just” need subsidies and incentives (or the ending of same) for “green” solutions, but the problem is much larger than that. We need to be operating “sustainably” at every level, in between departments, across legislation.
If regulation is blocking us, get it changed. If changing legislation is too slow, refactor. We must go faster.
It's easy to be gung ho about having other people use inspiring, untested technology. But it's not so fun when you're the teaching example for why regulations are slow moving.
"Sorry your house fell down, but we never thought to test this stuff at temperatures that low. I mean, we thought Texas was a hot place!"
Bureaucracy like that is always a short term obstacle. US building codes are not much of a quality or technical challenge though if you consider that Tokyo has typhoons and earthquakes and is planning a 350m skyscraper with CLT. I'd say anything suitable for that, ought to be acceptable for construction in most of the US.
Compared to the damage that hurricanes do in the US to flimsy plywood buildings, it will probably more than be able to compete with that. Building standards are perhaps slow to change but not necessarily very advanced in the US. But you are right that this type of change is slow to implement.
from what i remember, it’s up to 6 stories in some parts of the country. i think it’s other aspects of the zoning and/or building code that tends to limit it to 3 stories—often podium style, with a concrete bunker foundation for cars with 3 stick-built stories on top.
for the record, i dislike this style because it reserves the most valuable square footage—the ground floor—to cars. the cars should go underground, allowing the ground floor to be used for human purposes—ideally mixed use, even just publicly accessible studio space for creatives.
yah, that’s an awesome building, especially the exposed beam interior. it’s interesting that they used nail-laminated timber, which is just regular lumber close-packed and nailed together with plywood, in place of concrete floors/ceilings. according to the site, they’ve moved on to using dowels instead of nails for this.
Lake of the Ozarks was in the news last year for our aggressive disdain for covid precautions. The shoreline is occupied by many 4-, 5-, and 6-story stick-built condominium buildings. I've never heard of one falling over, but sometimes they do burn...
Looks like giant plywood. I'm actually really curious how it handles moisture content changes. Does it crack and is it dimensionally as stable as plywood?
Well, the short answer is that it is being used in Tokyo to build a sky scraper that is 350m high. You would not do that with plywood. Also, Tokyo has earth quakes, high humidity and typhoons. So, apparently it's up to that job and if it can work there, it can work pretty much anywhere.
also, CLT can be combined with steel to create stronger load-bearing members, while also being more aesthetically pleasing, effectively replacing concrete for class A construction of tall buildings.
>Lignin is what makes wood rigid and brown. Somewhat counterintuitively, Hu and his team removed the wood's lignin polymers in order to make their wood even stronger.
>The lingin removal allowed the team to compress the wood under a mild heat of around 150 degrees Fahrenheit. Without the lignin binding together the wood's cells, the scientists were able to make its cellulose fibers very tightly packed.
>When the fibers are jammed together...the wood's fibers begin to form hydrogen bonds.
So essentially they found a different (more natural-sounding for sure) way to polymerize cellulose. Right now bamboo or sugar cane are broken down and polymerized all the time via a different process to make plant-based plastics, rayon, etc.
We have, for all intents and purposes, an unlimited supply of carbon and iron. Assuming we one day get over our FUD of nuclear energy (which with the use of breeder reactors is considered a renewable form of energy), it follows that steel itself can be considered renewable.
Can we all stop for a second and appreciate the "Graphical Abstract"? IMO it's great, and every paper that where such a thing is reasonable should have one!
I think this is an article describing the same process, with more detail than the abstract above. A quick ctrl+f lists Teng Li's name in both so probably the same research group.
(Originally found on /. several years back)
Permali is a commercially available hardened wood with impressive properties, but it's based on impregnation with a resin which is not the most environmentally friendly process. A particularly interesting application of Permali is the nuts and bolts fastening the ATLAS-I Trestle (said to be the largest wooden structure in the world) together, since the nature of the facility required use of a dialectric material for the large fasteners.
The resin process has definite downsides though... I'm curious about the chemical process involved in this proposal. Historically, chemical treatment of wood has been a significant source of environmental contamination. Although modern precautions reduce this problem, it'd be a big step forward if the chemicals involved here are pretty safe.
I have a tiny bit of advice I might be able to lend here, for experimentation purposes mainly.
Regular hardwood can be heat-treated to increase its density and compression strength considerably, in the most basic form this can be done at home by heating it... slowly... up to ~400F (typically just holding it over a hot-plate until it's light-medium brown. You'll want a temperature-stable oven for wood more than a cm or so thick)
This won't provide the same density this study has achieved, but it'll give you a quick proof-of concept for next to no cost.
In the article I believe they also chemically alter the wood by removing lignin with a boiling sodium hydroxide solution. Basically dissolving out the 'dead weight' and leaving more cellulose, which is what's giving wood most of its strength.
They do also use physical compression under heat, which wouldn't be too hard to achieve with mere run to home-depot, but I'm not sure how much effort you want to put into this as of now.
Yeah... I don't want to make this stuff, I want to use this stuff.
It would be great to get an understanding of its performance specs. I may be able to specify hardened wood in place of steel, aluminum, magnesium machined parts in high-end ecologically conscious consumer products... but not without some understanding of the engineering specifications and a source of material.
My best guess would be to contact someone from the study group directly via email and ask about obtaining an engineering sample for a potential commercial product (no really, they'll probably appreciate it).
At this point the wood is likely still being produced in situ (i.e. a few guys making it in a phys/chem lab).
The more interest is shown to them, the more likely they are to start looking at contracting the process out, thus making material easier to obtain and lower cost.
From what I've read, I'd expect it to behave similarly (in yield/toughness/hardness) to cast aluminum but with a tendency to split along the grain still, for machining purposes. So fairly hard, but not super ductile. The density will be in the same ballpark as magnesium if my math is right.
But... 'ecologically conscious' won't mean anything until production can be scaled up. When you're measuring things in raw carbon-footprint, it won't be able to break even with recycled pop cans merely due to the low-quantity batches they're processing now.
It could be viable in mass production based on a previous article I read in Nature. The process seems simple enough that I could replicate it in my garage with some effort, so I think there's some potential there. It's just a question of whether it can beat traditional metals economically, with a slight edge in aesthetic appeal for your high-end customers.
I'll give you a more specific reply along with the parent poster while I'm at it...
You definitely can cut meat etc, with densified wood, just don't expect it to hold an edge like your steel cutlery, especially if you're using with something besides a soft cutting board. The article mentions oil-treatment so it probably won't absorb water in normal kitchen use.
In terms of edge-retention there just isn't a good alternative to steel atm. This wood will likely preform around the same as unhardened steel or aluminum, So it'll cut but you'll need to sharpen it frequently.
If you're looking more for fancy-pants artistic appeal and don't mind high price, there's always obsidian blades out there from small-time makers. They'll be about as good as ceramic sharpness-wise, but look a lot nicer IMO.
Whenever I hear about renewable trees I cant help but think how policy failures often lead to more and more forests being destroyed.
Perhaps it would be better if we stop over commodifying trees in general and try to reduce our reliance on them and hopefully partitioning them off from the economy could encourage regrowth
Places like Washington State have had replanting programs in place since well before I was born. In the US we have more trees now than we did 100 years ago, forestry and forest management as a problem was solved 50+ years ago.
There's the issue of disappearing rainforest in the amazon, but that's largely due to the fact that growing food is a more valuable use of that land than forest, and has nothing to do with the economic value of the wood on the land.
Of course I cannot access the full text article, but the claim that this HW can be sharpened and become "3 times sharper" than "most commercial table knives" sounds not very scientific.
Since "table knife" means the typical dull cutlery knives (as opposed to e.g. steak or kitchen knives), I have no doubt that wood (hardened or not) can be sharpened like that.
Not only, a "good" knife can be measured by its sharpness (and still the 3x sounds very little scientific) but also by the durability of its sharpness, there is a a youtube channel[0] by a guy that makes blades out of "everything" and they are actually sharp, but how much do they last (and last sharp enough) is unsaid, and in the end of the citation it seems like they propose these HW knife as a replacement for plastic cutlery.
(Can't read the damn paper, even with University journal access. Why is academia so fundamentally stupid? Is it not obvious to a scientist that when your paper comes out it would be a good idea for a lot of people to be able to read it?
Thanks to Cell Press for extracting profit to hold back scientific progress.)
Anyway I presume this relates to the group's previous work, where they boil the wood in sodium hydroxide to leach the lignin and then compress it. The final product doesn't have any resin additives, so is not a composite.
I wonder how fire resistant hardened wood is. I can imagine cities like Chicago having a hard time to use wood in commercial buildings with history launch as "The Great Chicago Fire"[0]
From what I've read, they are pretty fire resistant because they are dense and so will char and burn slowly. There have been a couple articles on here in the last couple years about "wooden skyscrapers" and they have made that argument.
I think wood can be quite fire resistant even with traditional modifications like charring. And it may retain structural integrity better/longer than steel. I think steel can become an enemy in a fire quite abruptly.
Chicago allows mass timber buildings up to 6 stories, although a developer has proposed an 80-story mass timber building. So that guy may do all the work to open the door.
As far as I know, the Earth's surface cannot meet humanity's current need for hydrocarbons, polymers or building materials. Biomass production is limited by sun energy and most importantly phosphorus and nitrogen cycles. Even hundred of years ago, people were already exhausting regenerative capacities and back then there were only around half a billion humans living on all this planet. Petrol chemistry and mineral exploitation saved Earth's ecosphere short term. But obviously that can't last forever.
It's nice to have functional carbon sinks and all, but we will never replace even the majority of petrol, metallic and mineral based production of today with biomass derived alternatives. The surface and geological cycles cannot support that. And food is priority. If phosphorus rock is gone, we're fucked for good.
A potential alternative survival strategy is to develop your country as fast as possible. Develop whatever technology will be necessary to win a potential future war fought over the scarcest resources. This development oriented strategy will probably consume a lot of resources, but survival is worth taking risks for.
This is pretty clear to me too. We survive on stored energy borrowed from the past. Energy and growth are basically finite. We do need to cut down.
We also need to develop tech (weather technique or technology) to reconstitute waste and refuse into the inputs for our food, buildings, transportation, etc.
> We survive on stored energy borrowed from the past.
It's worse than that: We fully rely on borrowed time!
Natural geological cycles to restore surface phosphorus span many thousands of years. Our current agriculture (food production) critically depends on mineral phosphorus, which may be exhausted in just four or five decades. And we retain none of that, but flush our soils into the oceans (partially through the toilet, literally). No phosphorus, no food. I wish everybody knew about peak phosphorus. (It's also a geopolitical near future issue as almost all phosphate rock is located in Morocco...)
> We also need to develop tech (weather technique or technology) to reconstitute waste and refuse into the inputs for our food, buildings, transportation, etc.
Yes! We also need to collect and recycle human and livestock feces and urine to prevent mineral loss. Those cannot leak from the ecosystems anymore - madness!
Honestly, I think it's possible humanity will barely not make it, comically, because no one wants to lobby for collecting people's shit, while everything else goes full Star Trek.
> no one wants to lobby for collecting people's shit, while everything else goes full Star Trek.
Ironically in Star Trek, the food from the replicator is made from human waste or that's what they say in recent seasons anyways.
I am optimistic about the ability for us to recycle human waste despite the lack of popularity though. Most people have no idea what goes on at water/sewage treatment facilities and they don't really care. Even with no regulation or subsidy, it will eventually become profitable to recycle this waste b/c of geopolitical issues like you mentioned.
I'm pretty worried that we wont be able to cut back on consumption though and will end up buried in piles of our own junk.
To add: I want to stress the phosphorus is used by all livings things part.
Plants get phosphorus from soil, animals get it from plants, predators from other animals, and finally microorganisms from our all remains. But it all starts with plants. We cannot grow "low phosphorus" food plants or anything. It's used in ADP and DNA synthesis! Phosphorus sits at the core of life itself. Every living cell on earth depends on what plants can extract from soil.
I think wood itself contains little phosphorus, compared to other parts of the plant. The inner rings of a tree are dead cells, a formerly living tissue, which condensed to cellulose and lignin. I assume the plant will not have phosphorus left there substantially. Phosphorus is needed to make ADP and DNA, by all living things, and is used in photosynthesis by plants, too. Quite useless in the middle of the dead wood zone. In woody plants, only the outer layers and leaves are living cells. If you leave those in the forest to rot, you retain some phosphorus.
You could also burn furniture after a century of use for energy and then bring the ash back into the forest to close the cycle, I guess. But that's requires non-toxic ashes - compatible paints and glues, no heavy metal agents and so on.
Either way, you are in competition with agriculture land use for food production. And bio fuels. And bio polymers. And bio... You get the idea.
Tho, if I had to guess, I would say wood probably is not the worst in terms of phosphorus leakage.
I believe one of the problems it solves is that steel has a tendency to erode over time. Hence major infrastructure failures. If structural elements can be made to the same strength as steel, using HW, which will not erode at the same pace of steel, than the expected lifetime of a structure increases and that is solving a real problem.
AFAIK it does solve a problem with steel, tho: Energy expenditure of production. You cannot make steel with heat generated electrically. At least not directly. Energy dense fossil hydrocarbons are powering furnaces today. You may replace that with generated hydrogen, but I am not sure the math checks out on a global scale.
No, that's still ignorant of ecological processes, I think. We need to adapt culturally/economically.
What do you think happens, if we continue as we do, but assume "infinte" ressourses? You would still exhaust regenerative/reparative capacities, accumulate chemical byproducts and waste - shift balances. See nitrification of water bodies.
The core problem is our lazyness to recapture uncompressed former dense resources; to operate closed cycle.
And well, I have my doubts we can establish the extend of space exploitation to meet our current e.g. global phosphorus needs within the next 30 years. Is phosphate rock even plenty around in asteroids?
The most interesting thing is the Force/Displacement curve. It shows some plastic deformation even after the breaking point, which is unusual for „hard“ Materials. May this just be some gloryfied Epoxy with wood as filler?
That stress/strain curve in the Cell Matter "Graphical Abstract" is garbage past the point of peak stress. If it's tested in their double shear jig as shown, once it displaces significantly (> radius of the nail) the force is more the pull-out force, basically just the friction between the hole and the nail surface. Or, the nail might just be digging an oblong hole in the shear jig. It's maybe interesting, but a regular stress/strain setup is better to lead with.
It appears they are relying on the hydrogen bonding in the cellulose after lignin removal, so it should be >50% wood, i.e. not an epoxy with wood filler.
They're taking the lignite out of the cellulose, and then compressing the resulting soft mesh into a harder material. A few years ago, "transparent wood" was a thing. That was taking out the lignite, and putting some transparent plastic in.
Not clear what's special about their compression step.
The heated compression step allows the cellulose to form hydrogen bonds with other cellulose fibers, which strengthens the wood and makes the epoxy redundant.
I'm surprised that this wasn't invented back when Henry Ford was trying to use agricultural products in autos. (The "hemp car" urban legend comes from that project.) Plastics were expensive, so there were attempts to use agricultural products as filler. The trouble was that cellular materials swell when wet. Plastic+ag waste didn't hold shape if used for exterior auto body parts. Same problem as Masonite, particle board, etc.
With enough heat and pressure, does this new material avoid that problem? Or is it a "do not get wet" product.
I live in a wood framed 5+1. Its great being in renewable wood building - but the downside is its a huge fire risk. Plus because of this the sprinkler system is vast - and keeps flooding apartments.
One of the steps to produce it seems to be soaking it in mineral oil. Maybe I missed something, but it seems pretty strong to call it renewable if it's made from fossil petroleum.
I am totally encouraged by this report. The sentence that really gets me from a companion paper linked below:
"Cellulose, the main component of wood, has a higher ratio of strength to density than most engineered materials, like ceramics, metals, and polymers, but our existing usage of wood barely touches its full potential."
It's just a beginning, but a good one. Hard to see HW replacing the myriad things we use steel or ceramics for, but intriguing.
When ceramic knives are produced, they insert a metal rod into them to ensure that they do set of metal detectors. I imagine they could do something similar here.
Article is paywalled (and sci-hub doesn't work), but the Brinell hardness of 31 while certainly higher than normal hardwoods, is extremely soft compared to metal - softer than even wrought iron without a heat treat. I'm sure it could be made "sharper" than cheap cutlery, but that doesn't mean it will hold an edge well. I'd also be curious how recyclable the material remains after the chemical treatment required to densify it - I would suspect it's like e.g. MDF / plywood which is very bad environmentally due to the glues.
Usually 'hardened wood' is just wood where the air has been replaced with epoxy. The problem is epoxy is expensive and not different enough from a pure plastic.
I think what you're describing is more often referred to as "stabilized wood", and doesn't involve the "densification" process as described by the infographic.
I'm not willing to pay for the article to read it, but it seems like this is pretty different from epoxy stabilized wood (which isn't particularly hard).
Stabilized wood is essentially as hard as whatever it's stabilized with. But yeah, the interesting concept is the densification. I dunno about replacing steel, but if soft fast growing woods can be converted into something closer to a hardwood, and the volume lost and extra time still puts it out ahead, that is pretty exciting.
Very reminiscent of the supposedly renewable & sustainable bamboo products that are anything but. I love bamboo, but flooring should make you think "plywood" not "waving groves of fast-growing giant grasses". It's another glue and epoxy thing.
Update: https://phys.org/news/2021-10-hardened-wooden-knives-slice-s... is a much better source.