Hardened wood as a renewable alternative to steel and plastic • Hacker News Board

Re: Hardened wood as a renewable alternative to steel and plastic

#201

Post by account_b » Thu, Oct 21, 2021, 11:35 PM UTC

korantu wrote: post #169

account_b wrote: post #55

Earlier quoted context omitted.

> 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 t…

Does it also mean that using wood at industrial scale is bad idea? Trees need phosphorus too

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.

Re: Hardened wood as a renewable alternative to steel and plastic

#202

Post by zardo » Thu, Oct 21, 2021, 11:42 PM UTC

katbyte wrote: post #137

soperj wrote: post #94

Earlier quoted context omitted.

It doesn't last so long in construction, rebar in concrete has like a 75 year lifespan no?

Does that not depend if it’s stainless or not?

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.

Re: Hardened wood as a renewable alternative to steel and plastic

#203

Post by gilbetron » Thu, Oct 21, 2021, 11:47 PM UTC

munk-a wrote: post #177

gilbetron wrote: post #157

Earlier quoted context omitted.

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.

Re: Hardened wood as a renewable alternative to steel and plastic

#204

Post by lindseymysse » Thu, Oct 21, 2021, 11:48 PM UTC

i_am_proteus wrote: post #175

lindseymysse wrote: post #119

Earlier quoted context omitted.

You can make steel with charcoal, which is carbon neutral in the end: https://aeon.co/essays/could-we-reboot-a-modern-civilisation... 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...

Thanks for that history. Alas, no such thing as a free lunch.

Re: Hardened wood as a renewable alternative to steel and plastic

#205

Post by Animats » Thu, Oct 21, 2021, 11:55 PM UTC

dan353hehe wrote: post #49

Animats wrote: post #26

Earlier quoted context omitted.

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.

That's all? No additives during the compression? And nobody figured this out before?

Re: Hardened wood as a renewable alternative to steel and plastic

#206

Post by huntertwo » Fri, Oct 22, 2021, 12:04 AM UTC

entropicgravity wrote: post #78

canadian_tired wrote: post #64

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…

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. [1] https://corporate.arcelormittal.com/sustainabili…

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.

Re: Hardened wood as a renewable alternative to steel and plastic

#207

Post by skohan » Fri, Oct 22, 2021, 12:09 AM UTC

canadian_tired wrote: post #64

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…

> 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?

Re: Hardened wood as a renewable alternative to steel and plastic

#208

Post by sp332 » Fri, Oct 22, 2021, 12:19 AM UTC

frosted-flakes wrote: post #188

turtlebits wrote: post #138

Earlier quoted context omitted.

All of these sound good, but the caveat is that they are wood + epoxy/resin/glue.

Why is that a caveat?

The knife in the article is just wood, with some food-grade oil on the surface.

Re: Hardened wood as a renewable alternative to steel and plastic

#209

Post by reissbaker » Fri, Oct 22, 2021, 12:30 AM UTC

megameter wrote: post #193

KennyBlanken wrote: post #178

Earlier quoted context omitted.

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…

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,…

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.

Re: Hardened wood as a renewable alternative to steel and plastic

#210

Post by politician » Fri, Oct 22, 2021, 12:41 AM UTC

gremloni wrote: post #192

XorNot wrote: post #187

Earlier quoted context omitted.

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 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.