Burning Plastic in the Himalayas – A consideration of the options
Initially when I think about burning plastic… I think of stinky black toxic smoke belching out polluting the otherwise pristine air of the Himalayas. It’s is not the image I want to have when thinking about the majestic beauty of the world’s highest mountains. However, having now spent 25 years travelling and leading tours in the Himalayas, I’m sad to say that plastic is as much a problem here as it is in most other parts of the developing world. And contrary to some parts of the developed world, there is NO way to cleanly dispose of it.
Every single water bottle, chip packet, Maggi 2-minute noodle wrapper and shopping bag that gets used in the Himalayas stays there, lining the once pristine rivers, lakes, streams, pathways, campsites, towns, villages and hillsides.
If the plastic is dealt with at all, it is occasionally swept into a pile and burnt in the aforementioned black smokey way… Or thrown into one of the great Himalayan rivers with the salutation “Chello Pakistan” as it winds its way through valleys across the Indian subcontinent on its way to the ocean… Or buried in a small hole, only to be unearthed some time in the near or distant future.
But generally, its not dealt with at all… it’s thrown casually out of the windows of countless cars, buses and taxi’s by the very same tourists who paid good money to come and gawk at the wonderfully idyllic nature the Himalayas is famed for.
The endless number of food, drink and accommodation operators who service the rapidly escalating numbers of tourists have nowhere to dispose of the plastic they offer their clients, other than to chuck it into a hole or a barrel and throw a match at the stuff. Often the wind catches a hold of it before a casual flame does, and that same plastic is now spread far and wide throughout the mountains, adding to the splendour with its multi-hued colours that resist fading even in the relentless sunshine.
Walking along the spectacular shores of Pangong Lake straddling the Indo-Tibetan border at 4500m is now an exercise in deciding whether to spend the time picking up Bisleri bottles, Maggi packets and Coke cans, or to doggedly keep one’s gaze on the horizon, trying to avoid the inevitable horror of what lies at one’s feet.
So… is there an alternative?
Well, the obvious solution to the global issue of non-degradable plastics is that they shouldn’t be made at all. There are various biodegradable alternatives that could be used if plastic packaging is required. Unfortunately, these are not used in an extensive way as yet.
Enter the “Rocket Stove”. Used extensively in European and North American cold climate regions due to their efficient use of fuel, rocket stoves are a simple concept in combustion that combines clever airflow with an insulated combustion chamber to achieve high operating temperatures.
It’s these high temperatures that are interesting. In a normal rocket stove situation, high temperatures are used to combust smoke particles in a way that makes the stoves both efficient as well as pollution free. In most of my other ramblings about rocket stoves, it’s the efficiency that is the featured ‘feature’. In this case, however, it’s the lack of smoke that’s interesting. Pollution free combustion is an elegant idea that could be applied to plastic in a low tech scenario.
High temperature incinerators have been used around the world by nations trying to deal with the mounting issue of waste for many years. It seems that if one burns the waste hot enough, it no longer “pollutes”. What that means in practical terms is that the complex molecules that make up many plastics are reduced to simpler (and mostly) non-toxic molecules by the combustion process. All it takes is high enough temperatures. The temperatures used in a government waste treatment facility in the USA range from 1800 to 2200F (940 to 1200C).
A well designed rocket stove can achieve 1100C+ quite easily (I’ve had a small unit on my test bench running at 1150C) so with a bit of tweaking 1200C should be quite achievable. And it can be done with materials that are cheap and easy to find, it’s just a matter of design.
Even if these low tech stoves are operating just below the ideal temperature of 1200C, the alternative should be considered. Plastics anyway are being burnt in low temperature barrel fires all over the place creating no end of toxic black smoke that wafts through villages, towns and valleys. Even an imperfect high temperature combustion has to better than that.
As a result of this, the Himalayan Rocket Stove Project now has 2 distinct programs:
- The social enterprise metal box rocket that is designed to keep people warm in their homes with a minimum amount of fuel combusted cleanly (wood and/or dung)
- The non-profit project aimed at educating Himalayan locals in how to use clay to make cheap, reliable large space heaters and rocket stove furnaces designed specifically for burning plastic in a clean safe way whilst also providing heat energy for practical use (eg: warming communal spaces such as nunneries, monasteries, schools, village halls, etc as well as heating water for guesthouses, etc).
With regards to burning plastics cleanly, testing at the Ladakh workshop in Leh has recently demonstrated that a specialised insulated clay rocket stove can burn plastics with no noticeable smell or smoke. Further testing will show whether the optimal 1200 Celsius has been achieved. (Having burnt out my original high temperature probe, I’m currently waiting for a new batch to arrive.)
Meanwhile, as testing continues, we are excited at the prospect of converting a useless waste product into a highly sought after energy source.
Having posted some photos of the initial test burn on Facebook, I was since notified about the possibility of releasing toxic chemicals that fall into the Dioxin and Furan categories. There are over 200 such chemicals and are widely regarded as extremely noxious and highly persistent. These are generally released in low temperature fires such as those which commonly grace the back of households across the globe. There is some question as to what temperature range is considered safe for combustion of these chemicals. As a result I am looking for a suitable research and testing partner, possibly a university or research lab that is interested to be a part of this project to find a safe and affordable means to deal with the issue of plastic waste in the Himalayas. Any contacts in this regard will be gratefully accepted.
Hi, I love the rocket stove, great project. I too am deeply concerned with the growing menace of plastic waste across the region (and world), and agree that it is a wicked problem, and agree that the way it is openly burnt now is about the worst thing that could be done, from an environmental-health perspective. That said, I think promoting burning it in rocket stoves as a solution is questionable. As you write, the claim of ‘pollution-free’ is also made for high-tech modern waste incinerators that burn at extremely high temperatures, but this claim has been ‘hotly’ contested, e.g. by the global anti-incineration network GAIA (see: http://www.no-burn.org/downloads/Gasification,%20Pyrolysis,%20and%20Plasma%20Incineration.pdf
Apart from the smoke and air emissions question, there is the residual ash that must be dealt with. Even if it is negligible in terms of volume, if it contains toxins or heavy metals from the plastics (and one needs to be aware of the many chemicals and metals in plastic packaging besides the polymer itself) it will pose an environmental-health problem when disposed.
Further, while I understand the impulse to talk of “converting a useless waste product into a highly sought after energy source”, I fear that such a framing could detract from the need to stem the tide of disposable plastics flooding over the region, and on the contrary could help normalise plastic waste and even, potentially, encourage more of it if it is seen as a ‘cheap’ fuel. Certainly this is not your intention, but I would hate to give any fodder whatsoever to Coke, Pepsi, Nestle et al., plus the plastic industry, to claim to be providers of ‘sustainable’ fuel for Himalayan villages.
What we need to do I believe is work towards political interventions to stem the tide of the packaged stuff in the first place (such as bans like Sikkim’s against polystyrene: http://www.northeasttoday.in/sikkim-bans-items-made-of-styrofoam/). Much of the packaging is of snack/junk food and beverages, consumption of which is also deleterious to the health of the communities. Why not work towards restricting and banning such products in the first place? A much more daunting challenge, no doubt, but I really don’t see any other way to sustainably tackle this problem. Technical, end-of-pipe approaches, whether dumping, burying, or burning, simply accommodate and at best ‘manage’ the problem.
Thanks for considering…
Hi Alex… it’s been a while since you made your comment, but I just now reread it and thought its worth a follow up. The issues you raise are well considered, and I am very much aware of the problems with plastic combustion you mention. I agree that stopping the problem at the source is of course the more desirable path, and hopefully that happens in our lifetime. In the meantime, I am curious about the conversation around which is the “lesser evil”… typical low temperature combustion versus imperfect but significantly less toxic high temperature combustion. Personally I’m not convinced either way, so I’m still reviewing the data and looking for input from those who have also considered this in detail.
just spitballing but what about adding a catalytic converter to a Rocket stove and burn plastic of course now a cheap construct becomes expensive but even if we stopped producing plastic yesterday there are mountains of it already
I don’t know enough about catalytic converters to understand if that would work so I’d be happy to hear more about that option if you do.The main toxic group of gases to deal with are the dioxins and furans. Then there is the ash as mentioned by Alex… so there is still more research to be done on this.
Since you make the vortex work for you, why not build these and kill off some of the old tires and plastics that infest India?
PS when will you export to OZ and do you need an agent cos I want a stove — cheers
That’s great… I love the idea of converting waste into energy products. And yes, we are in the process of exploring the Australian market, have a look at our link here: https://himalayanrocketstove.com/crowdfund-eco2/
You can contact me directly on email@example.com
In about 1980 I “hired” Dr. Larry Winnarski from Corvallis Oregon after a Hornby Island man had been hiking in the above treeline South American mountains. There where fire wood had to be carried kilometers up hill ,my freind took note of the unusualy efficient wood stoves. These stoves had come about through the intervention of Aprevieco . A group of volunter engineers and siciencetists. that exchange knowledge with our Southern Hemispher sisters and brothers.
Long story short I dedicated my shop ,myself and two paid employies for more than eight weeks to build a two meter diamater round ,five meter above ground with three cyclone exhausts and one meter below ground of fire bricks. This giant rocket stove was our attempt to head off the transfer of all our islands (year round population of about 1000)post consumer paper waste.
Accurately measured by three pyrometers I borrowed from local potters, after a one hour warm up we acheived combustion temperatures over 2200 degrees.
Once warmed up this Winnarski’s giant rocket stove burned 100% visual clean. No smoke. Doctor Winnarski tells me that Apriveicho has helped to fabricate over 3500 similar units in Central and South America. Our oldest son while studying Engineering at The University of Victora wrote a few hundred page study preserving the details of our research.
Hi Tim, great to hear about your massive rocket! That’s quite the beast. Does it still work? Do you have any pics? Did you ever use it for plastic waste? Love to hear more… you can reach me directly on firstname.lastname@example.org
Hi Tim do you have a link to the research paper. Are there measurements and design drawings. I am definitely interested in this unit for my greenhouse operations
Political reform of course would be nice, but in this region, it’s a long shot at this point. I live in Kyrygzstan and we recently built a rocket mass heater and our emmissions are much les than the thick black smoke that comes wallowing out of our neighbors houses. Air quality here is horrible in the fall and winter because people set fire to piles of leaves and trash which doesn’t even really burn, just smolders and smokes. Technically this is illegal, but environmental laws aren’t enforced. Plus trash pick up is spotty or non-existent in many areas (even in cities), so for many people there aren’t good alternatives to burning. Also, most people here have never in their life thought about how their choices might affect the environment. Peoples understanding of what is “clean” is very different here than in the west. So it’s not just political reform that is needed, you have to change the culture – not to mention build up the infrastructure to make other options possible. All of this takes a lot of money – which will unfortunately never reach it’s goal because the whole political system is corrupt and incompetent.
Bottom line as I see it, as long as plastics remain a profitable options for the trash producers, we will keep seeing the market flooded with plastic products and we will be left to deal with the trash.
Hi, nice article, i feel the same way totally about plastic and its “ugly”effects on the environment. Got the same idea as you (and many others) just to burn it efficiently in a closed stove. I hope to be able to build one here in Indonesia where I am currently travelling. As far as the dioxins go, it’s really just an issue with PVC or other chlorine containing polymers, which are in the minority. Let me know how it goes!
Hi Radek, interestingly it is not just PVC’s that are able to produce dioxins. I also thought that was the case due to the presence of Chlorine in PVC. After reading more on the topic, I found that there is enough chlorine present in air to combine with the other chemical products in the volatile temperature zone between 200C and 500C to make up the dreaded Dioxins and Furans. I’m still researching ways to combust plastic safely in low tech situations, but it is certainly problematic.
Hi there, I think that people forget that wood, just like plastics is also a polymer and its combustions produces a whole spectrum of “evil chemicals” including carbon monoxide, tar, furans, acrolein and if there is volatile chlorine present in the neighbourhood it will produce dioxins too. I am going to do a bit of research on the combustion products of polymers and wood and write a blogpost on it. I have written a blog on burning of plastics and get also a number of furious comments. Keep up the good work!
Bio-degradability of plastics is not a solution. The myth of bio-degradability is that plastic somehow rots down into compost. In reality, oxidized plastic just brakes down into smaller and smaller pieces of plastic then enters the food chain. This is what is killing all the ocean birds.
Increased bio-degradability also does nothing for legacy plastic waste build up. Regulation in general does not work in the developing world because there is no money to enforce compliance.
We need to BAN all forms of bio-degradable plastic, so it does not crumble and become impossible to identify and collect. Out of site out of mind. Keep it looking more and more horrible as it piles up! Eventually people will be forced to do something about their own mess, if they want to keep their tourist industries alive.
Hi Philip, I haven’t looked deeply into biodegradable plastics, but my understanding is that there are various different base ingredients, many of which do actually break down fully, such as corn starch. I think what you’re referring to are non-biodegradable plastics, which do just break into smaller and smaller pieces without degrading back into a form the environment can safely deal with. I certainly agree that NON-biodegradable plastics should be banned urgently and replaced with nature compatible degradable alternatives.
Those base ingredients must have originally come from an earlier environment. Possibly bacteria could convert them into an inert substance.
I’ve made a special kind of rocket stove that can reach above 1000C easily, with any kind of trash & wastes as input; biomass, plastic, rubber, oil (both lubricant and cooking oil) . I name it “jet stove”.
The main differences are the addition of oxygen preheating, material drying, and after-combustion treatment on the system.
Its not intentionally design for toxic minimizing but for energy output optimation. That’s why it is integrated with steam tube to pump water from well and/or to move Tesla turbine and permanent magnet generator to produce electric power.
Though it still in prototype phase, I hope it will solve our toxic problem considerations in plastic burning, too
Hi, the question that keeps coming to my mind through this blog is… is there a low tech methodology for incinerating plastics, tires, etc in a way that can be accurately tested and verified to produce no dioxins or other hazardous compounds? What tests are available to assess the various prototypes and is it the case that incinerating these materials at a high enough temperature will produce a burn with no toxins being released in the smoke. Dealing with the ash is another matter.
Yes, your questions are the right ones. I have been going slow on this project for exactly the reasons you have mentioned. However, I have been getting increasing demand for a low tech high temp incineration product, so I will be likely working on developing the prototypes over the coming 6 months. Assessing the emissions and the ash will require professional third party input. Dioxin and Furans are tricky to test for, so a professional lab will be required for this.
Dear Russel, thank you for starting this very interesting discussion.
Following a recent visit to Africa, where I witnessed the devastating effect of plastic and other waste littering on small towns and rural communities, I share entirely your concerns. Safe combustion of plastics in a domestic environment is very difficult but you are quite right that today unsafe and inefficient burning of plastics is commonplace and usually without any energy capture or benefit; only environmental and health dis-benefits.
Reducing plastic use (especially packaging and single use plastic), reusing plastic and recycling initiatives to give waste plastics a second or third life should be the priority it is clear to me that the investments and infrastructure required to achieve even limited results in these communities is a barrier that will not be overcome in the forseeable future. Affordable options, even if imperfect, are required. These communities do not have even basic household waste removal let alone recycling options.
It was particularly sad to see that the litter and household waste disposed during the dry season was largely accumulated in the dry watercourses, waiting patiently for the rains to wash into the rivers and the ocean. There are so many NGO’s and other organisations focused on cleaning up the oceans but I find it very hard to find any information on organisations that are looking at ways and technologies and projects that could stem the tide of waste flowing into the oceans. I note that there are several organisations organising litter picking and clean up but in these communities they still have nowhere to put the collected waste and the cycle is not broken.
Anyway, enough Blah blah, I would be very interested to hear how your research has developed and whether you have had any success in dealing with this crisis in the Himalayas and if you were successful in reaching any universities or labs that were able to help you?
I also wonder weather a more small scale industrial approach could be successful in medium sized communities. For example a project to build community services (clinics, community centers etc) could bolt on a “stove” that could provide heat, hot water and maybe also some electricity; at least in part fueled by waste. On such a scale dealing with the potential toxicity and efficient combustion may be easier to achieve.
I see this as only a step towards longer term solutions but if developing waste to energy on a small, low tech, low cost scale can lead to more collection of waste and infrastructure this can further lead to identification of more valuable waste and recycling initiatives will hopefully follow. People will innovate if there is value available.
Hi Bruster, thanks for your thoughts on this. Yes I am still pondering the issue and have tested another prototype that uses high tech materials for maintaining a higher combustion temperature, however I am not yet ready to release a design to market as yet. I am still looking for a collaborative partnership with an institution able to do emissions monitoring in the testing phases. In general, your thoughts about a larger than domestic unit are being considered, perhaps guesthouse / hotel / village sized units could be more effective and safer to run, and provide heat for hot water storage units. I will post more about this when I get a chance, hopefully later this year.
I was so impressed by two of your initial tests of rocket garbage incinerators here in Ladakh, and am eagerly waiting for further developments. As you know, SECMOL school and I will be some of your eager early adopters and testers.
Best of luck!
Just returned from 3 weeks in Zanzibar. Beautiful, but disfigured by the ever present plastic waste, the most common being (PET?) water bottles. When i arrived here, I was actually trying to find a good DIY rocket stove model to suggest for the restaurant I ate at most there, that could replace the classic 3 stone stove they use.
Using a rocket stove should be able to even be used to get energy from the plastic waste while creating less pollution than with the common “burn it in a field” approach.
Did some looking for what elements and how much could be contained in different plastics. https://www.vtt.fi/inf/pdf/technology/2014/T186.pdf
has a lot of info about that. Sometimes the variation is so big it can be hard to use:
Table 39. Total possible halogen concentrations in plastics and rubbers. *Only
stabilizers and flame retardants are considered.
Cl (mg/kg) in PET 10–122000.
Would be interesting to have some university laboratory analyse ash from high temp burned PET bottles for example.
Yes I am also interested to get a university lab involved with testing. The various waste products from burning plastics is very complex.
I am grateful that I have stumbled across your website and this thread. This is an idea that I am toying with as well and am eager to collaborate on. What do you think about just doing the test ourselves. As far as I can tell what we would need is an air particle counter. Specifically one made by an engineering company, so we would be able ensure that the machine will read for whatever elements that are of concern. Hopefully it will read all that are present as well as amount. Then we will know the answers with data to support
Scratch the air particle meter. I spoke with some environmental engineering labs and it seems like we will be looking at needing a gas chromatograph mass spectrometer or perhaps a different instrument. They will be reaching back out to me with suggested approach as well as cost for instrument or for how they can test it. Seems like they may have some mobile testing options that may work. So if we can get that worked out then the question will be what is the best design for a rocket stove to use for this purpose. I assume that the design will need to be whichever can burn at the hottest temperature and thus having a higher chance of combusting all possible particles. This my assumption, but am not for sure.
Hi James, you are correct in that a particle meter will not be sufficient, but I like the idea that basic testing could be conducted with suitable equipment in-house. I am interested to hear what you find out about the gear you’re researching, as I am now in a position to start testing prototype waste burners in my new workshop in Byron Bay. If you feel to get in touch, you can reach me directly on email@example.com
See H S Tarm OR Boxi; you will find a Danish WOOD FIRED BOILER that has been in use for more than 50 years .(i FIRST SAW ONE IN MY WIFE’S PARENTS HOME IN DANMARK IN 1973!)IT BURNS AT 1800 TO 2000 DEG F!
AND , YOU CAN BUY 1 FOR YOUR FARM OR COUNTRY HOME IN U S A
AND, YES I OFTEN BURN PLASTIC ARTICLES -COFFEE CANS JUICE BOTTLES ETC ; AS THERE IS NO SMOKE OR SMELLS AT THOSE TEMPERATURES!
The solution is theoretically simple. Supply stoves for burning plastic to the people or tell them how they are built. They will go out there to collect plastic and burn it efficiently to cook and satisfy their heating requirements.
Hi Russell, Great article. Thank you. I have been an advocate for small scale combustion of plastic at high temperatures in my tiny forced air ‘blower stoves’ for ultralight backpacking. https://timtinker.com/miniature-dome-stove-a-three-in-one-stove/
The combustion temperatures are very high, although I can’t measure it. In blower stove mode it is not a gasifier stove, but rather a quasi-gasifier. I routinely burn our waste plastic packing materials that are almost unavoidable on long trips. I take the absence of any noticeable smell in the exhaust gas as good evidence of clean combustion. The aluminium in plastic gas barriers burns up very nicely too
I certainly do not encourage the use of more plastic, but clean, remote and small scale burning of necessary waste and the irresponsibly discarded waste of others is a noble thing to do.
I even make a range of tiny fire starters from waste. The ‘flame drizzle sticks’ that are made out of plastic milk bottles make the quiver of starters complete. They will drizzle droplet of flame downwards into an infant flame within damp fuel sticks that are at first reluctant to burn.
Can you recommend a cheap sensor that I can measure my combustion temperatures with?
Thanks again and keep up the good work
Hi Tim, thanks for your comment and nice to see your project on the dome camping heater, that’s a great concept! With regards to a temp gauge, I suggest you get a K-type thermometer and probe with rating up to 800-1000C for the temps you are likely to experience when you are using the blower. These are not too expensive and readily available online. Some multimeters also already have the K-type temperature capability and then all you need is to buy the probe. Good luck with your experiments!
For gas analysis, I would recommend ALS Environmental. They can send you a prepared, vacuumed metallic container to collect the gas sample. You send it to them and they analyze for the components that you request. I am not affiliated with this company, but have used them at my laboratory.
2655 Park Center Drive, Suite A
Simi Valley, CA 93065
Thanks very much for the contact. I am based in Australia and the testing mostly happens in India, so if they are able to send to either of these countries that would be ideal. I’ll look into it.
This may be helpful:
In the Humanure Book, Jenkins tells how his sawdust got contaminated with diesel. He used the sawdust anyway and composted it in the hot pile, like he recommends for humanure composting, and had the results tested. No evidence of diesel fuels were in results. Perhaps the ashes could be used for composting humanure to help digest any harmful leftovers.
I have read the blog with great interest. I love how you are just going to it and experimenting with a solution. It is clearly important to your heart country around the Himalayas. The rest of the world has many people who have commented , yes it is a world problem.
I have read of such problems before, and no doubt they have similar problems with reducing toxic gases. I am sure CSIRO has addressed this same basic problem for the last 20 or more years. Despite their access to ample laboratory equipment, they have failed to gain sufficient political buy in to actually using combustion of plastics. I see that some people who constitute part of that resistance have sprouted on this blog also. If I may conflate a few respondents in opposition, who I paraphrase ” even if polymers were forever forward made 100% compostable now, there would still be a massive waste problem to solve”
With regard your solutions toxic combustion products, I make the following observations.
CSIRO employed ionised gas to raise the effective reaction temperatures to even higher values. What they call plasma assisted combustion. In the end, I believe that they were successful in avoiding significant toxins in the gas stream. However, this also required an excess energy input (gas flame + high voltage ionisation) and was costly. Here is a link to the tech sales pitch of a more expensive solution: http://www.phoenixenergy.com.au/plasma_gasification.php. Singapore also burns all of its municipal waste successfully. In many respects the large insulated rocket stove may be more energy efficient and practical for developing nations. It may need that someone does the numbers, if the amount of toxins emitted can be reduced to an acceptable level, can the net “cost” be negligible compared to continued solid pollution?
A final note on toxic emission. The inorganic oxides from burning consumer plastics are likely to be less in volume than from burning plant waste, and may be used as a feedstock for bricks or rockwool insulation. The flue gases will never be free of some toxic gases due to the thermodynamics of high temperature combustion. But could they be cooled until the gas dissolves in water. At that stage in the process, have you considered partnering with a biologist to find an algae/bacterial system (for example) which could be fed the mixture of CO2, SOx and NOx as a feedstock? In other words divert the toxic air stream to a managed bio remediation pool? Crazy I know. But is it feasible , that the toxic stream could produce an organic fertiliser?! I believe that is also being researched. As an example … https://www.researchgate.net/publication/287974232_Current_Techniques_of_Growing_Algae_Using_Flue_Gas_from_Exhaust_Gas_Industry_a_Review
I also would like to contact you about using a rocket stove for use in tiny houses in Australia!