Making rubber from dandelions 1

[cranky108]

http://news.yahoo.com/tire-makers-race-turn-dandelions-rubber-081139461--finance.html

So you thought your backyard weeds were a pain. Well maybe not.

 

[ornerynorsk]

Many plants have latex, I would think it would work equally well. Milkweed, Jackfruit, Burdock, nettles, thistle, just to name the ones I can immediately recall. The articles' figures for yield seem a bit optimistic.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[msquared48]

Is this a leftover from Woodstock?

Mike McCann, PE, SE (WA)

 

[cranky108]

More interesting is that the plants can also be eaten if one were hungry enough.

So natural rubber can be grown in more places, and possibly replace synthetic rubber (probally not). But it reduces the dependice on tropical land for supporting the modern world.

 

[urgross]

Dandelion greens arecommon in slads, and are regularly farmed in northern Europe. It also makes a really crappy wine.

 

[btrueblood]

I like arugula better.

 

[TomDOT]

IIRC, Edison and Ford used goldenrod-derived rubber tires during one of their many camping tours of the US, roughly 100 years ago. I don't recall whether Firestone went along on that one or not.

"weeds into rubber" isn't exactly new.

 

[cranky108]

The world of modern medicine is full of discoveries that at one time were folk medicine.

The only questions left here is if it is cheeper to produce rubber from dandelions? How do you harvest them and how fast can you make a crop out of them?

The existing process involves growing a tree, then harvesting it.

I would assume with dandelions the plant to harvest time would be much less, and the crops can be rotated from year to year. So it appears to be a process that has a quicker expantion capability to better deal with changes in demand.

 

[TomDOT]

While time-to-first-harvest for dandelions is undoubtedly faster, my understanding is that the trees can be tapped for rubber many, many times. Productive life is ~25 years after maturity, and each tree is tapped every few days. Something like 3,000 harvests per tree.

 

[MintJulep]

to breed a type of dandelion native to Kazakhstan whose taproot yields a milky fluid with tire-grade rubber particles in it.

And they could have some interesting modifications. For instance, German researchers have bred the plants to grow to up to a foot (30 cm) in height, dwarfing many of their backyard cousins.

Yes. Let's introduce genetically modified non-native plants on a massive scale. Nothing could possibly go wrong with that.

 

[KENAT]

The existing process involves growing a tree, then harvesting it.

Do they harvest rubber trees these days Cranky?

I thought they tapped them repeatedly.

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[moltenmetal]

There are also biological routes to making cis-isoprene which involve microorganisms instead of plants or trees. None of them are commercial yet as far as I know.

They "harvest" the rubber trees at the end of their service life and make cheap furniture from them, but as noted the rubber is produced by tapping live trees and collecting the latex.

I was surprised to read on Wikipedia that natural rubber production is still about 40% of total rubber production, so I did some digging and the numbers are more or less accurate. I would have thought that SBR would have dwarfed it completely, but there you go- it's still cheap enough and the properties are great for some applications.

Where we need a bit of help is with the disposal of the used tires. They burn cleanly when burned in a properly designed combustor and have an incredibly high energy content, and are far cleaner as a fuel source than most coals. But because everybody has seen at least TV images of smoky, sooty burning tires (which is more pyrolysis than combustion), people think they are a dirty fuel and won't permit them to be burned in many jurisdictions. So instead, they sit in piles and burn by accident, creating major environmental impact even after the firefighters manage to put them out which is not easy by any stretch of the imagination. There are some re-use options (such as the use of recycled rubber crumb in asphalt etc.), and some people have tried to pyrolyze them to make liquid fuels, but there are still mountains of used tires to be found.

 

[TomDOT]

The mountains of tires have been rapidly depleting in Texas - some for crumb rubber in asphalt, some other small uses - but most of them are going into the cement kilns as fuel.

 

[moltenmetal]

Great to hear that TomDOT- that's exactly where they should be going in my opinion. That's where most of the chlorinated waste should be going too.

 

[TomDOT]

Hm, I really don't like having increased chlorides in concrete due to corrosion issues.

 

[moltenmetal]

...but they do that here in northern climes already to improve the freeze tolerance. Guess there's plenty of Cl- to worry about already from road salt so what's a little more?

 

[TomDOT]

Yeah, the concrete guys here had a presentation on chlorides for freeze resistance - they don't think the corrosion tradeoff is generally worthwhile in our environment. Entrained air microbubbles was the preferred solution. But it's certainly not a settled subject, and we have less freeze/thaw and less road salt than most.

 

[cranky108]

I have heard where used tires were ground up and mixed with coal for power production (and given renewable tax credits, which I question).
Old tires aren't just used for door mats any more.

Taping a tree is not harvesting the latex? Since when is cutting down a plant the only way to harvest a crop? You don't cut down nut trees to harvest the nuts do you.

I have to admit I haven't taped very many trees, and I am sure there is an art that works best. However how many years does it take to grow a tree to harvest age?

 

[TomDOT]

Cranky, usually about 7 years for a rubber tree to be ready for first harvest, then about 25 years of useful life.

 

[cranky108]

I see it as rubber trees don't grow everywhere, but dandelions do seem to grow in more places so it should allow for more production of natural rubber. Also I would think dandelions would be easer to automate the production and latex extraction which would make natural rubber less expencive. Sorry for the poor people taping trees now.

The next question would be if there would be quality differences, like there is between natural rubber and man-made rubber (or natural and natural rubbers).

I would also think with dandelions that crop rotation would be possible, allowing a farmer to change to a crop that maybe more needed next year.