
A man who paves India's roads with old plastic - wallflower
https://www.theguardian.com/world/2018/jul/09/the-man-who-paves-indias-roads-with-old-plastic
======
zackmorris
Lignin from hemp could be a possible bitumen replacement:

[https://gizmodo.com/a-compound-from-plants-could-replace-
bit...](https://gizmodo.com/a-compound-from-plants-could-replace-bitumen-to-
make-ro-1693050702)

Looks like hemp is 5-30% lignin depending on the type, with female hemp having
roughly double the lignin content by dry weight:

[https://www.sciencedirect.com/science/article/pii/S223878541...](https://www.sciencedirect.com/science/article/pii/S2238785414000982)

[https://www.hempbasics.com/hhusb/hh3fiber.htm](https://www.hempbasics.com/hhusb/hh3fiber.htm)

Also algae oil can be converted to a bitumen-like tar with roughly 55%
efficiency, so if we assume the best algae is 50% oil by weight then we end up
with about 25% tar by weight (I can't find confirmation of this, so they might
mean 55% tar from algae directly):

[http://news.algaeworld.org/2015/04/algae-bitumen-could-
soon-...](http://news.algaeworld.org/2015/04/algae-bitumen-could-soon-pave-
roads/)

Perhaps these could be combined with recycled plastic to make an asphalt
derived purely from biomass and recycled materials.

~~~
Sephr
The best genetically engineered algae is over 90% oil by weight.

------
ucaetano
While I applaud the change in perspective into looking at plastic as a
resource, not a curse, this article smells of BS:

> He received a patent for the process in 2006. Since then, almost 10,000km of
> Indian roads have been paved using his technique.

This sounds like random stats thrown around by government officials,
particularly because later in the terribly-written article, it mentions:

> Nonetheless, at least 16,000km of road have subsequently been paved in the
> state of Tamil Nadu. The national government has since approved the idea and
> sanctioned at least 13,000km across the country to be paved in the material
> as well. Of this, 8,600km have already been completed, says Dr IK Pateriya
> of the rural development ministry in Delhi.

The numbers simply don't add up.

> Shredded plastic below 70 microns (including the multi-layer plastic shreds)
> is then sprinkled over it.

A shredder capable to shredding materials down to 70 microns is absurdly
impressive, and would likely cost hundreds of thousands of dollars. Unless the
article means that some of the plastic films being used have a thickness of 70
microns. Honestly, it just looks like the author read 70 microns in the source
material and threw it in to impress without knowing what it means.

> A stone tile measuring one square metre has a manufacturing cost of Rs 100,
> approximately £1.. 60 plates would be sufficient to construct an eco-
> friendly bathroom, says Dr Vasudevan.

£60 to build a toilet in India, plus labor, construction, etc? This is a very
bad idea. The median household income per capita in the poorest states in
India is under $1000/year. Just the cost of the toilet is much higher than the
median monthly household income of one person.

That's before we get into the issue of using cement and concrete in the
"plastone", which are very carbon-intensive (concrete generates about 400kg of
CO2 per cubic meter). It would be much cheaper, simpler and greener to use
wood to build it, which can be carbon net-negative.

~~~
r_singh
You might be surprised to know that the govt. spends around 220$ to build a
single toilet in small towns / villages in India under the Swachh Bharat's
sanitary division.

I even have a friend who found it super lucrative to build toilets around his
factory for the govt. and hence took it up to build a few toilets every day to
add a stable revenue source.

This may not add up given the per capita, but that's how it is, welcome to
India.

Rural toiled fund allocation raised to Rs. 15000 per toilet:-
[https://www.thehindubusinessline.com/economy/policy/rural-
to...](https://www.thehindubusinessline.com/economy/policy/rural-toilet-fund-
allocation-raised-to-rs-15000-per-unit/article23125148.ece)

~~~
vwcx
"The problem [in India] isn't just a lack of toilets -- it's a lack of toilets
that people want to use."

National Geographic's deep-dive on the issue:
[https://www.nationalgeographic.com/magazine/2017/08/toilet-d...](https://www.nationalgeographic.com/magazine/2017/08/toilet-
defecate-outdoors-stunting-sanitation/)

~~~
r_singh
Yeah, I'm quite aware of that being an Indian and living here all my life.

Bill gates has written about this problem as well. Heck we've even got comedy
movies surrounding this issue.

However, the toilet building programs are isolated from these facts, they
don't even have proper maintenance programs in place to make sure their
usable. Every infrastructural spend in India has leakage of money towards
those who have power.

------
Blinks-
I found an interesting article that breaks down some of the potential problems
with this process and the risks involved with heating plastics and trying to
differentiate between plastic and PVC (they release different compounds when
heated, both potentially problematic).
[https://www.thenewsminute.com/article/heard-about-miracle-
pl...](https://www.thenewsminute.com/article/heard-about-miracle-plastic-
roads-heres-why-its-not-solution-our-plastic-problem-36927)

~~~
schiffern
> the risks involved with heating plastics ... (they release different
> compounds when heated, both potentially problematic)

The article makes this claim:

> Studies reveal that even heating plastics such as PP, PE and PS releases
> moderate to highly toxic emissions – carbon monoxide, acrolein, formic acid,
> acetone, formaldehyde, acetaldehyde, toluene and ethylbenzene.

Citing this[1] paper. But the paper only shows toxic emissions from _recycling
plants operating at 200-300 degrees Celsius_ , not at 165 degrees Celsius (ie
the peak temperature of asphalt).

[1]
[http://www.sciencedirect.com/science/article/pii/S0045653508...](http://www.sciencedirect.com/science/article/pii/S0045653508013532)

edit: btw the article's broken vimeo link was the trailer to Chris Jordan's
incredibly powerful film _Albatross_ (then titled _Midway_ ):
[https://www.albatrossthefilm.com/](https://www.albatrossthefilm.com/),
[https://www.youtube.com/watch?v=PLkTTJW4xZs](https://www.youtube.com/watch?v=PLkTTJW4xZs)

~~~
mod
From the OP's article:

> Asphalt is heated to a temperature of 170C (338F). Shredded plastic below 70
> microns (including the multi-layer plastic shreds) is then sprinkled over
> it. The bits of plastic seemingly disappear, melting into the red heat.

~~~
marzell
"seemingly" disappear. How is this any different than, say, the banned
"microbeads"? This just puts tiny fragments of plastic into the environment,
which is even more difficult to collect/recycle/sequester than plastic bags
and bottles. I think this is a well-intentioned, but overall terrible idea and
I hope they are forced to find a better solution.

------
justboxing
I may not be fully understanding this, but isn't this process just going to
make the Ocean plastic pollution a lot worse?

i.e.

Indian Monsoon Rains wear away the plastic from the road over few months,
years....

The plastic particles drain and make it to the rivers.... eventually to the
indian ocean...

... few years later, we now have large scale plastic particle pollution in the
indian ocean thanks to this ingenious technique of mixing plastic with
bitumen.

~~~
pjg
I doubt it.

Unless the paved roads are physically close to the Ocean it's unlikely the
plastic will be washed away to ocean water. (BTW: Plastic decomposes much
faster in sea water than on land - again that doesn't make it ok to dump it in
sea water though )

Furthermore the plastic is "heat treated" and then mixed/layered with Bitumen.
While the chemical reactions have not been explained it's likely that some
form of chemical binding is happening at those temperatures i.e. Plastic is
undergoing chemical conversion - at least at amalgam level.

~~~
emmanuel_1234
It doesn't have to drain to the ocean, just to the nearest body of water,
which will take care of the rest of the journey, no?

------
virtuabhi
Little bit disappointing. Instead of 10 parts of bitumen, it requires use 9
parts of bitumen and 1 part of plastic. Add to that the heating of plastic to
a tight upper bound lest it releases toxic fumes.

~~~
schiffern
> Add to that the heating of plastic to a tight upper bound lest it releases
> toxic fumes.

165 degrees Celsius is the maximum temperature for asphalt itself[1][2], so
conventional spreading equipment is designed not to exceed that. The plastic
is melted by the hot asphalt, not separately.

[1]
[https://www.fhwa.dot.gov/construction/reviews/revhma01.pdf](https://www.fhwa.dot.gov/construction/reviews/revhma01.pdf)

[2] "Hot mixed asphalt is manufactured at temperatures between 270°F and
325°F." (that's 132-163 degrees Celsius)
[https://www.forconstructionpros.com/asphalt/article/10297263...](https://www.forconstructionpros.com/asphalt/article/10297263/why-
tracking-temperatures-is-key-to-successful-asphalt-paving)

------
sandworm101
>> Plastic wouldn’t clog our oceans or our landfills if we didn’t throw it
there in the first place.

The big worry isn't so much the oceans being "clogged." It's the
microplastics. It's the tiny bits of plastic that bio-accumulate. The turtle
choking on a plastic bag is one problem, the repercussions of plankton
absorbing tiny beads of plastic into their cells another. Making roads out of
bulk plastic doesn't help the microplastics issue. Spreading it out over
thousands of miles of road may actually be worse than landfill it in a single
place.

------
phyzome
I seem to recall that asphalt may be ripped up and recycled -- I wonder if
this stuff can be recycled the same way.

------
nowarninglabel
If anyone could help, I'm working with a company led by a young woman in Kenya
who is actively creating paving bricks out of used plastic bottles. They need
about $25k-$50k for machinery to help scale out the operation, and we're
trying to find some people who can help secure this funding. Contact me if
you'd like to help with doing something good with them.

Her company website:
[https://gjengemakers.wixsite.com/mysite](https://gjengemakers.wixsite.com/mysite)

~~~
yarosv
Looks scammish

~~~
coderintherye
I suppose that is probably true that a lot of very early stage startups may
appear that way. That said, I've worked directly with them in Kenya and can
attest to the fact that it's not and they are doing good work pushing this
concept forward. If you have suggestions for other things that would help
establish the veracity of things, do let me know.

------
linuxftw
For this to work, the roads need to be better or same quality, and the usage
of plastic needs to be more economically efficient.

Road quality being the same, the addition of plastic, including the labor,
additional equipment costs of spreading it, storing it, producing it, must be
cheaper than the cost of using just the bitumen.

Additionally, processing the recycled plastic has to be cheaper than just
making new plastic for this process in the first place.

If this works out, it would be a good use of some waste materials.

------
danans
> Since plastic coats the stone and interacts with the hot bitumen, it’s
> properties change and it doesn’t break down when exposed to light and heat.

This is a tall claim that needs substantiation. I'm no chemist, but I think
most organic compounds, plastics included, break down with heat and light
exposure.

Perhaps he thinks his process makes the plastic break down more slowly, but
again, evidence needed.

------
hguhghuff
I read recently about children getting cancer from sports fields made from
recycled car tyres.

~~~
aarongough
Source?

~~~
hguhghuff
References abound but here’s the top one
[https://www.google.com.au/amp/s/amp.cnn.com/cnn/2017/01/27/h...](https://www.google.com.au/amp/s/amp.cnn.com/cnn/2017/01/27/health/artificial-
turf-cancer-study-profile/index.html)

I’d think twice before making roads from (even more) toxic chemicals.

------
Bromskloss
Do we not get to see a picture of such a road, or am I missing it?

------
snambi
plastic is disgusting. no matter however we disguise it.

~~~
dang
Maybe so, but please don't post unsubstantive comments to Hacker News.

~~~
lightedman
Literally half of your posts are unsubstantive and tell other people what to
do, like a control freak. Hypocrisy, thy name is dang.

~~~
dang
That's true of course, except that it's my job and, alas, the community
doesn't solve this problem without effort. Some medicines are toxic and one
uses them when the alternative is worse. I wish we knew a better way.

In case it helps, moderation comments are even more tedious to write than they
are to read.

~~~
lightedman
How about simply allowing conversation to just happen? Would you like it if I
told you how you were to speak out in public?

It's the GOLDEN RULE. Something you seem to have forgotten in its entirety.
You're literally trying to treat someone as if you were their parent. You
shouldn't be surprised to find people like me stepping up since you've already
coerced people into cowering down.

~~~
dang
Unfortunately all our experience with internet forums is that "allowing
conversation to just happen" leads to the death of the forum. At least once
the forum gets beyond a certain size.

