Photo: The ArboSkin bioplastic façade created by Stuttgart University’s ITKE (Institute of Building Construction and Structural Design) demonstrates the possible architectonic and constructional applications of bioplastic materials. | Image credit: Institute for Building Construction and Structural Design
To conclude this series about bioplastics and the biodegradability (or lack thereof) of plastic products and packaging, I want to discuss the future of what I consider to be one of the only viable alternatives to plastics derived from non-renewable resources: durable bioplastics.
The key word here is durable, because biodegradable plastics of any composition are not the long-term sustainable solution we need. When you compost a biodegradable plastic cup, that polymer can no longer be reused and maintained, meaning all of the energy and material inputs are lost in the soil. They can make sense in certain circumstances, particularly in countries that have large volumes of organic landfill waste. India is a prime example, where about 50-60 percent of the waste sent to landfills is organic and could be composted, but only as a short-term waste-reduction strategy.
Durable bioplastics that can be recycled present us with a more viable opportunity to mitigate our dependence on oil-based plastics, but realistically offsetting our dependence on petroleum polymer first requires decreasing the overall demand for plastic. We’re expected to consume about 300 million tons of plastic in 2015 alone. To put that into perspective, in 2013 the production capacity for bioplastics across the world was 1.6 million metric tons, covering about 600,000 hectares of land (one hectare = 2.47 acres). It doesn’t take long to see how much additional farmland we would need to grow enough bioplastic feedstock to match the current plastic demand.
Without a decrease in demand, it should be obvious how this could affect food production across the world. Take, for example, the issues caused by the rise of corn-derived ethanol in the United States. In 2000, 90 percent of the corn grown in the U.S. was used for food and livestock feed. By 2013, only 60 percent went to food and feed, while 40 percent went to ethanol production. Greater demand for feedstocks such as corn and sugarcane for bioplastic production would only compound this problem, invading food production even more. The only way to mitigate this is by reducing the consumption of and demand for all plastics.
Reducing demand is challenging because of plastic’s ubiquity. Still, consumers, manufacturers and government entities can help decrease its use. By educating the public, for example, we can build a larger population of conscious consumers who read labels and make more sustainable purchasing decisions. Government incentives, such as taxing materials or banning certain forms of plastic packaging, can be even more effective. Manufacturers can even increase production efficiencies while reducing their use of plastic by making lighter product packaging.
With a more manageable demand for plastic, shifting to bioplastics and plastics sourced from renewable raw materials becomes far more viable. This would also give us the opportunity to develop a more comprehensive bioplastic recycling infrastructure, something clearly lacking today. Today, most bioplastics are seen as contaminants to the recycling stream, meaning consumers still can’t place them in their blue bins for recycling. But as plant-based plastic becomes more popular with manufacturers, the incentives to develop recycling processes for them increase. By building that recycling infrastructure, we could maintain the bioplastics we produce and limit the need for new polymer altogether. Eventually, we could considerably (and sustainably) mitigate our use of petroleum-based plastics.
We have a plastic obsession, and it’s not going to disappear. Still, the need to reduce our consumption of finite, non-renewable raw materials is only going to intensify as the years progress. The answer doesn’t lie in plastics that biodegrade, which has extremely limited (and short-term) applications. Durable bioplastics that can be recycled and reprocessed over and over again give us an opportunity to finally transition the plastic market away from oil — humanity’s favorite unsustainable, non-renewable resource — once and for all.