The plastic revolution

Whilst travelling, we’ve witnessed how several Asian countries such as Cambodia and Indonesia have turned into plastic junkyards. Inland and coastal areas are littered with a colourful mixture of bags, bottles, cups, trays and everything else, it is truly a sad and terrible sight. A lot of countries, not just in Asia, suffer from bad solid waste management. Moreover, littering seems to be a deep engrained cultural element. Whilst care for the environment seems to be on the last stage of people’s and the government’s interests, the nature is suffering and people too.

Owing to the favourable properties of plastic – strength, durability and light weight, we embraced them in all areas of life. Plastics have created a revolution and improved the quality of life immensely, however, nowadays they seem to be one of greatest plagues of our planet.  I can’t enumerate the number of times I came across an article talking about the great plastic vortex the size of Europe in the Pacific, and that the ocean will soon contain more plastic than fish.

Economic incentives

I believe that people (the end-users) are responsible for the plastic crisis, and should also be the ones to fix it. The great question then is, how can we convince people to undertake action? According to the US Environmental Protection Agency, economic incentives are a strong tool in changing consumer behaviour. Along these lines, some countries introduced a deposit for plastic bottles. But what about the other plastic: wrappers, bags, ropes, their value is too low to be considered for recycling.

The chemical elements of plastic

Most of the packaging plastics which pollute the environment are based on two to four chemical elements. Polystyrene, polyethylene and polypropylene are made of carbon and hydrogen, whilst PET (polyethylene terephthalate), used for bottles, contains also oxygen. Nylon, a polyamide, which is used to make fibres, also contains oxygen and nitrogen in its structure. These elements are essentially the same ones that fossil fuels are made of. This should be of no surprise, since plastics (long chain hydrocarbons) are also made of the same crude oil, as their “short chain” relatives- gasoline and diesel.

In other words: if burned well, plastics create the same products as wood and fossil fuels -> water and carbon dioxide

 

Recycle or burn plastics?

In conventional terms, it is environmentally more sound to recycle plastics than dispose them. This approach, however, has so far proven quite challenging and more frequently results in “downcycling”. But even downcycling requires large centralised facilities with advanced sorting lines and plastic recovery processes, which is very expensive and not applicable to solve the pollution problem.

So, you were always told that burning plastics is bad for the environment. Indeed, incomplete combustion of any hydrocarbon creates noxious smoke. As the above image depicts, burning plastics can create the same products as fossil fuel and wood. In waste incineration facilities, thousands of tons of plastic burn worldwide daily, generating heat and electricity.

Let’s be honest, who has never burnt a piece a plastic? Have you ever watched a bag or a bottle crumple when it comes into the scorching heat of the campfire, and then singe away with a smokeless flame? The experience of burning plastic here in Asia has been a different one. When the dusk comes, people start small fires on the roadsides: a few dried palm tree leaves and a pile of plastic waste smoulder under a cloud of black smoke and the familiar smell.

Burn plastic in a stove

Burning any material well and without smoke and noxious fumes needs a high temperature and plenty of oxygen. This is best achieved in a stove, where the heat is concentrated and can be put to good use.

I am no stove design expert or a fire engineer, but whenever making fire (a camp fire or a BBQ), I keep three rules in mind. To keep the fire burning you need 1) Fuel; this can be any combustible material- usually wood or gas, but plastic does the job as well. 2) Oxygen; 21% of air is made of it and a continuous supply of air is a must.  Then the last factor is one people tend to forget, since it is not so obvious. 3) Heat transfer; solid fuel does not in fact burn, the gaseous products of its decomposition do. Decomposition takes place by supplying heat to the solid fuel. If not enough heat is supplied, no gaseous products are created and the fire stops burning. Most fires are based on these principles and a fire will keep growing until one of the three components becomes limiting. Then it will reach a “steady state combustion”.

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.

The “rocket stove” concept is a good one to adapt, as well as the ideas shown on this site for wood burning stoves. Importantly, stoves should be designed from easily obtainable materials such as steel barrels or old propane cylinders.

People will soon find out, that burning plastic in stoves is advantageous. Plastic does not contain literally any moisture, neither does it produce as much ash as wood does. When plastic gets this new role, it will become economically interesting to go out there and pick the pile of plastic rubbish and burn it efficiently, instead of throwing it on an open fire or using wood or charcoal made of cut down trees.

Another benefit of burning plastics is that it can help in reducing deforestation. There are numerous reasons for deforestation. One of them is cutting wood for the use as fuel. Frequently, wood is first charred to make charcoal, a clean burning fuel suitable for indoor stoves and pits. The dark side of this material is that charcoal is best made of hardwood trees, which tend to grow slowly. The process of charring also removes often more than 70% from the usable energy from the wood, which could otherwise be used for cooking. A prime example of deforestation for cooking can be found on Haiti.

What are the downsides?

As most solutions, this one is not free of flaws as plastics such as PVC (polyvinyl chloride), which is used for plumbing, can create more dangerous products of decomposition – such as corrosive HCl gas; and several plastics. Usually the hard plastic used in motorbikes and cars contain flame retarders, which are too not the friendliest chemicals and may create toxic fumes when burned. Based on what I’ve seen, these plastics are a minority and PVC and hard plastics are denser than water and will sink If they end up in the sea.  What you see washed up on the shore are light packaging materials and foams.

Conclusion

Plastic pollution is killing many animals and is undoubtedly aesthetically damaging the environment. Burning them might be the best way to quickly improve the situation. If people recognise the benefit of burning plastics in the right stove, it will save them money on fossil fuels, stop plastic pollution, limit deforestation, and improve the quality of life. Combustion of low value packaging plastics is not a totally new idea and a company has already received an award for it. Are you convinced that burning plastics is the solution? Are you up for developing a simple and low cost efficient burner? Let us know!