As pervasive as plastic is in today’s society, it may be surprising to know that it dates back to the mid-19th century. It is a legacy of the echo of the Industrial Revolution in Europe and North America. It is highly flexible in its applications, variable in its composition, cheap to produce and disposable.
The first three parts of that description are spot-on, but the fourth is a term with too much breadth to be accurate. Plastic may be easily thrown away by the user, but it is very hard for it to be ‘digested’ ecologically. According to the U.S. Environmental Protection Agency (EPA), plastics represent eight percent of garbage production by weight — an estimated 14.4 million tons annually.
Eight per cent may seem reasonable, but that paints all trash with the same brush. Paper, yard trimmings and food scraps make up about 65 per cent of our garbage but are digested by bacteria back into soil. The better way to look at plastic trash is that when only considering non-organic waste, it represents nearly 25 per cent, second only to metals as a waste category. Metal as a denser material also takes up a lesser volume of space, all other things being equal. Beyond that, metals are recycled at a higher rate due to prices that recyclers can get for the raw materials.
In a landfill setting, generally speaking bacteria does not digest plastic, rather it relies on ultraviolet light to break down the molecular bonds that hold plastic together, ostensibly just dividing plastic into progressively smaller pieces (and that is only if it is exposed to light and not buried). In an ocean setting, plastic waste breaks down faster because of the light exposure, but causes problems in marine life (another way to think of that is our food supply) and leaches toxic compounds into the water.
Getting back to the first paragraph of this article, the intersection of having many different types of plastic made cheaply mixed with the disposability issue causes a large recycling challenge. Plastic’s use in food packaging and chemical storage compounds this. The cost and energy of separating plastics, eliminating contaminants from food and chemicals, then reconstituting it into saleable quantities (usually pellets to be remoulded) would cut into the profitability of selling recycled plastic. It would be more expensive for customers relative to buying newly-produced plastic. In economic or cost accounting terms, it is a classic buy versus recycle/fix/make paradigm.
Though we’re not generally addressing the waste challenge by eliminating its wholesale use, the recycling and waste problem is bringing forward some innovative approaches. Initiatives vary in their scope and current stage of development, but there is movement in the right direction. Some initiatives change the composition of plastics to be biodegradable, some deal with post-consumer material with distinct bacterial or other treatments to speed decay and/or minimize environmental harm, while others address reconstituting plastic for direct re-use or re-sale.
One of the world leaders in innovating the recycling world is MBA Polymers. You may have seen a 2011 TED talk given by Mike Biddle, co-founder of MBA Polymers. They have developed what is likely to be a plausible approach at large scale, economically viable plastic recycling as an extension of the landfill business. MBA Polymers has designed a recycling infrastructure for what they call above ground mining, sifting and sorting polymer types from one another, as well as separating plastic from the metal components in appliance and electronic waste. They are headquartered in the UK, with operations in Austria and Guangzhou, China. They claim to use 80 per cent less energy than the production of brand new plastic, and to save one to three tonnes of carbon dioxide per tonne of plastic produced versus traditional manufacturing. When you add the access to millions of tonnes of previously buried metals, closing the resource loop on plastics can be economically worthwhile and a game-changer ecologically. When recycled back to its original pellet form for re-sale, it has changed a supply chain into what they deem a supply cycle.