There is a surge in the sustainability discussion.

And among the key pet subjects, circularity features prominently.

What’s circularity?

It is a short form for the circular economy.

It’s summarised by three Rs:

Reduce, Reuse, Recycle.

More Rs have been incorporated into the philosophy ever since but these three form a solid backbone of this ideology.

The circular economy seeks to:

REDUCE the production of waste…

Find different ways of REUSING what is waste…

or

Use the waste as a raw material in the manufacture of other products – also known as RECYCLING

RECYCLING

Among the three, recycling seems to be the most popular.

And this is because we are attracted to a process that creates value out of waste.

Imagine the biogas created out of kitchen waste…

Imagine essential oils made out of orange peels…

Recycled products create enterprise and are environmentally friendly.

A great thing.

PLASTICS

Imagine businesses that have blossomed out of recycling plastics.

Some have come up with amazing products.

However, quite a number of plastics cannot be recycled and this is where another form of recycling checks in – chemical recycling.

CHEMICAL RECYCLING

When plastics are cut into small pieces and used to reform other plastics, this is called mechanical recycling.

In other words, the chemical structure is not interfered with.

Only the physical structure of the plastic is changed into a different product.

But chemical recycling is a whole different ballgame.

Here, the plastic is broken down into molecular form usually by the power of heat, chemicals or enzymes.

Some microorganisms are known to digest plastics using enzymes but this is still to a large extent a subject of reserach.

So many chemical recycling plants revert to the other two forms of recycling.

THE BENEFITS

A cost-benefit analysis dictates that we look at both sides of the coin.

In this case, what are the pros of chemical recycling – especially using chemicals or heat?

Well, first, hard to recycle plastics are broken down to their constituents – these constituents are called ‘monomers’.

Plastics are made up of monomers joined together just like metal pieces joined together to make up a chain.

These monomers could then be reused to manufacture new plastics.

Second, the breakdown of plastics into monomers reduces the possibility of the same plastics converting into microplastics.

Microplastics are micrometer diameter plastic fragments that are a result of break up of larger plastics. 

These fragments become mobile in our air, water and might even find their way into the food chain

They are suspected of causing environmental damage and pose a health risk.

Since chemical recycling does away with the plastic structure, the possibility of its conversion to microplastics is reduced.

THE COST

First, because heat or chemicals are used, chemical recycling produces other pollutants.

Picture pyrolysis – breakdown of plastics using heat – which is one of the most common methods of chemical recycling.

When plastics are exposed to heat, they do breakdown to their monomers – just like we talked about previously.

However, monomers aren’t the only products in this process.

Risky pollutants such as polycyclic hydrocarbons, dioxins and particulate matter may also be produced.

These airborne hazards are associated with a range of health complications such as heart disease and cancer.

But these risks aren’t only the preserve of pyrolysis.

Using chemicals to break down plastics introduces new risky substances in the environment.

Take for instance the use of acetone to breakdown styrofoam.

Styrofoam alone is extremely difficult to recycle let alone introducing another chemical in the mix – acetone.

Secondly, chemical recycling has a greater hidden cost in the name of energy.

Picture a recycling plant using pyrolysis.

Since heat will be required, it needs to come from a source of fuel which most likely will be fossil in nature.

Implications?

Release of greenhouse gases and other hazardous pollutants coupled with a high energy bill at the end of the month – which is what we have been trying to avoid all along.

Lastly, chemical recycling indirectly creates an incentive for manufacture of hard-to-recycle plastics.

Just ask yourself which plastics are hard to recycle…

PET – used to make soda and water bottles

PVC – used in electrical fittings

Polystyrene- used to make single use cups and plates

Polythene- used to make plastic paper…

and the list goes on.

Now, not all of these products are single use.

For example electrical fittings will stay intact for a while.

But what happens to plastic bottles, plastic paperbags, and single use cups/ plates?

They’ll just be disposed in the rubbish dump creating an eyesore and eventually degrading to microplastics.

But what if chemical recyclers pounce on these plastics?

They’ll not only rid the waste dump of them but will be using them as raw materials for more products.

In other words, plastic manufacturers will feel the need to continue making non-recyclable plastics which end up being raw materials in a dirty and energy intensive process.

Instead, these plastic manufacturers ought to stop making the non- recyclable plastics in the first place.

IN CONCLUSION

Chemical recycling aids in remanufacture of plastic products from plastic waste.

However, it is inefficient in energy usage while at the same time releasing key pollutants in our environment.

In any chemical recycling venture, the costs and benefits need to be weighed in order to determine their overall effect on circularity, the environment and people’s health. 

So it’s a conversation that needs to keep going.