Biopolymers: Emerging Plastics

With the growing media focus on energy and carbon it is easy to lose sight of all the things that contribute to our energy usage and our carbon footprints. The strict focus on small parts of our economy’s environmental challenges only emulates how prone we are to isolating concepts and events rather than continually viewing our actions as an interconnected whole. Waste production is another prime place for progress that is not so far away from carbon caps and the renewable energy debate. The collection, sorting, compacting, dumping and even recycling of waste all uses energy so to strip down its girth is a boon to our greater goals. When it comes to waste, plastics stand out as a prime target for reorganization and an answer that quickly comes to mind is biopolymers—naturally based plastic compounds.

The statistics are not friendly. When it comes to waste, we are careening in the opposite direction. According to the EPA, over the past half century the average waste stream of a U.S. citizen has nearly doubled from 2.7 to 4.6 pounds per day for a grand total of 254 million tons of trash in 2007. Of that grime of garbage over half is comprised of yard trimmings, food scraps and paper products with the last comprising 32.7% of our waste stream. Plastics are not far behind however, as the fourth largest component of municipal trash contributing 12.1% or 30.7 million tons annually.

So why target plastics? Well to start, when we throw out plastics they are likely headed for a landfill (at best). While they are not the largest component of our waste stream, when it comes to recycling and reuse they are the lowest. In 2007 we recycled only 6.8% of our plastics, the lowest of any product material. Not all plastics are created equal with some being notoriously difficult to recycle. Given that most communities only accept polyethylene terephthalate and high density polyethylene (the 1’s and 2’s on the bottom of containers) 69% of products will rarely even be collected for recovery.

Furthermore, once discarded plastic is sitting around it is going to stay there. Forever. I recently became aware of the infamous Pacific Garbage Patch, an enormous stew of floating plastic trash that is condensed within circulating currents in the middle of the Pacific Ocean. We have no shortage of evidence to support stemming the use of plastics.

Plastics from Plants

Biopolymers are a fascinating group of “organic” compounds that have been gaining speed and attention over the past decade. Instead of relying on the petroleum feedstock of traditional plastics Biopolymers use a base of natural compounds to build their products—most commonly starch/sucrose, cellulose, polyesters and soy—to virtually grow our plates, cups and trash bags out of the ground. The industry strives to eliminate the fossil fuel devotion to plastic—which is nothing to scoff at. Nearly 10% of American oil consumption, or 2 million barrels a day, is used to produce plastic.

Perhaps most importantly, biopolymers can biodegrade over time which means, when it comes to trash disposal, our reoccurring mistakes of laziness and short-sightedness would not be infinitely relived for centuries to come. Many proponents of the industry use this to classify the process as carbon neutral given that the energy required to produce the plastics can be offset by the carbon sequestered in the new plant feedstock.

So having our plastic “grow on trees” sounds like a good deal, but it begs the question what has been holding the industry up? Firstly, it turns out that biodegradable is a loose term that can require different levels of energy input for material to completely breakdown. Some claim that biopolymers require industrial bio-degradation facilities (they do indeed exist) which super heats the waste to induce swift reduction to base compounds. Without this, even a biodegradable plastic bottle could take decades to fully decompose. Such facilities are currently a rarity on American soil which prompts questions of new infrastructure and the cost of a shifting industry standard. Different biopolymers are also suited for different things, making the match to final uses more tricky.

A large question mark for me is how similar is the biopolymer proposal to that of ethanol? Both are products that start with organic feedstock and are championed as sustainable alternatives, but ethanol’s use has become greatly debated here in the U.S. Some opponents wonder why we should be planting crops for ethanol instead of lowering food prices while others still claim that the production of ethanol requires enough energy to negate the environment benefits of its use. How do the same arguments compare to biopolymers?

I intend to find out. Leading minds in the industry of Biopolymers will be convening in Chicago this coming September for the 2009 Biopolymers Symposium. Intercon has been invited and my attendance will undoubtedly find answers to these questions and more.