But I heard that biodegradables don’t degrade? Well, yes and no. First the good news. Biodegradable plastics can be completely broken down into biomass, CO2 and methane when processed in industrial composters, where the temperature, humidity and presence of bacteria can be controlled. The resulting products can then be used to generate electricity or heat buildings as renewable energy sources. (Read more about the process)
And what’s the not-so-good news? Some manufacturers claim that their biodegradable materials fully decompose in 49 days, but scientists have found that at best, biodegradable shopping bags break down only by 3–9% in natural conditions. Plastics that end up in our seas have no chance of degradation due to the low water temperature.
So what’s being done? There are promising solutions to capture the confetti-like plastic debris endangering marine life and their food-chain, such as a new cylinder-shaped device called Remora, which removes plastic in an energy-efficient way. (Read more here)
But what do we do with the captured plastic? It’s now possible to break down plastic solid waste to recover energy and even refashion it into fuel. One is pyrolysis, which is more eco-friendly than burning or gasification as it minimises the emissions of CO and CO2. Another is de-polymerisation, which divides the long chains of molecules in plastics into high-value waxes, or even fuel.