1-877-97ALGIX | info@algix.com

Addressing End of Life Issues of Bioplastics

 Overview 

There are many benefits that plastics offer to the world, but the overall perception that people have concerning plastics is negative.  Some of the primary concerns with plastic consumption are the environmental pollution and sustainability of the plastic life cycle.

In a recent study by the American Chemistry Council, people were asked about their perceptions of various packaging materials. Nearly 1/3 of the people surveyed had an unfavorable view of plastics, as opposed to only 7% that had an unfavorable view of paper or cardboard.  In fact, of all the materials surveyed, plastics were ranked at the bottom of the list. Consumers clearly expressed negative perceptions about plastics in relations to the impact on the environment.  The top three reasons against plastic in order were: Not biodegradable, bad for the environment and not all plastics are recyclable.  All three of those concerns are end of life cycle issues. (1)

The weakest point in the plastic life cycle is at the end of the products useful life and disposal. Although the industry is committed to recycling, currently 55% of all municipal solid waste and 85% of plastic waste ends up in landfills. (3) Landfills are the least desired management strategy for plastics. “A more significant problem for land filling is that plastic wastes now constitute about 10% by weight and about 20% by volume of the municipal waste stream. Since plastics are essentially nondegradable, their volume will not shrink and plastics may eventually consume a disproportionate amount of landfill space.” (Rustagi, 2011) None of the material resources from plastic products are recovered. Long term risks of contamination of soils and ground water by some additives and breakdown by products in plastics pose continual organic pollutants. (Hopewell. J, et al., 2009)

“Plastic production has continued to climb every year since the 1950’s. The outlook for 2015 is 6 billion pounds of plastic production. Globally, 450 billion pounds of plastics are consumed, which averages out to be 65lbs of plastics usage per person annually.” (Mosko. S, 2013) In addition, the world’s population has recently hit 7 billion people, and is expected to hit over 9 billion by the year 2050. It’s vital to manage waste issues that will result from this dramatic population growth.  (4)

 

Recycling Issues for Bioplastics                   

Biodegradable polymers have the disposal options of landfilling, incineration, anaerobic digestion, home and industrial composting and recycling. (Yates, et al.,2013) One of the problems is that bioplastics are not easily recyclable.  Most people have the misconception that all the plastic they put in their recycling bins are 100% recycled into new plastic products. However, only 10% of plastic waste gets recycled in the USA, and up until recently, a good portion of that was actually sent to over to China. This should be looked at in a positive light by seeing it as an opportunity to look at plastic as a valuable resource instead of scrap and should spawn creativity to find new end of life uses for this “unwanted” plastic.

Another perception is that bioplastics are automatically considered to be a total contaminant to current recycling streams. “The increased use of bioplastics and biocomposites may have further serious implications for the recycled plastics industry, as it could potentially lead to the contamination of collected conventional plastics by bioplastics, affecting the quality and physical integrity of the resulting materials.” (Soroudi et al, 2013) “Regarding the recycling of PET mixed with PLA, the limitations of NIR sorting systems, not only their difficulty in identifying polymers with special colors or structures, but also their high costs.” (Soroudi et al, 2013) However, according to a recent study conducted by the National Packaging Consortium in Italy, up to 10% of starch based shopping bags could be combined with traditional PE shopping bags with negligible impact on the technical performance of recycled PE.  The results were the same when up to 10% of flexible, compostable packaging material was combined with common plastic packaging. (6)  Given the increasing popularity of PLA and bioplastic packaging entering the market, the recyclability complications represent a challenge for recyclers to cope with a more diverse stream of plastics. Thus recycling does not offer the flexibility and economics needed for complete utilization of the waste plastic streams.

 

Solution…A Two Prong Approach    

             The chart below shows recycling in conjunction with energy recovery and how they work together.  The model has two complementary approaches to resource management ;  in one scenario the plastic material ends up as a new product; in the other scenario the material ends up in a Waste- to- Energy facility and is converted to fuel or electricity.

Diverting Plastics from Landfill

On the left side of the diagram is recycling.  Once the plastics and the materials leave the household, they are placed in recycling bins and sent to a recycling center for separation, cleaning, grinding, reprocessing and pelletizing.  The resin pellets are then made into new products.

On the right side of the diagram, there is the energy recovery cycle.  Plastics leave the home, but these plastics are not candidates for recycling.  The plastic waste is placed in a bin for pick up, and is transported to an energy recovery facility where it is processed through methods such as, combustion, gasification, or pyrolysis. These processes can produce a ratio of co-products such as oil, syngas and/or electricity. “Because plastics are typically derived from petroleum or natural gas, they can generate almost as much energy as fuel oil, although the much higher amount of energy initially required to produce the plastic is lost. (Rustagi, 2011) “The amount of energy recovered can also depend on whether it is used for electricity generation, combined heat and power, or as a solid refuse fuel for co-fueling of blast furnaces or cement kilns. A process called Liquefaction can convert the plastic waste into diesel fuel, alternatively gasification or pyrolysis can produce hydrogen rich syngas or heavier crude oils.” (Hopewell. J, et al., 2009)  Pyrolysis is especially appropriate for products or waste streams that contain waste plastics, organic waste and inorganic solid waste materials because the pyrolysis process can convert any organic material into a hydrocarbon rich bio-oil that can be further refined into products conventionally produced from petroleum. These non-recyclable organic waste residues have high conversions yields to liquid and gases in the pyrolysis process.”(Adrados, 2012) In both cases of reuse and energy recovery, waste plastic is converted into a valuable resource (fuel or electricity) through thermo-chemical processes.

Energy Values of Non-Recycled Plastics

 

The recycling industry in the US started in the 1980’s, however after nearly 30 years, the U.S. has some of the lowest recycling rates in the developed world. The average annual recycling for the USA is around 8% and Europe has a 24% recycling rate. (Mosko.S, 2013)

 

 

US Lags on Recycling, Recovery

“Recycling biopolymers may be more favorable energetically than composting, however, the sorting and cleaning processes may make this impractical and if biodegradation has been triggered, the degraded material will be unsuitable for recycling. Incineration (with sufficient energy recovery efficiency) may be an end of life option which does not require biodegradation of the materials, but could have lower environmental impacts than industrial composting.” (Yates, et al., 2013)

Leading States in W2E and recyclingIn the future, energy recovery is expected to gain more popularity in the US for several reasons. First, as recyclable plastics are processed over and over, they lose some of their mechanical properties and can no longer be effectively recycled for input into new products.  Secondly, as recycling capacity is likely to increase, it won’t be sufficient or logistically feasible to process the amount of waste that an expanding population will continue to produce. Third, the intrinsic energetic value of non-recyclable plastics is a valuable resource to produce energy.  We need to control our energy costs and improve our energy solutions, and plastics can help achieve this goal.  Energy recovery through waste-to-energy processes provides a clean alternative and sustainable energy source that will be there as long there is a waste supply.  From the chart above, the U. S. lags far behind other European nations in recycling and waste- to- energy. The U.S. has only 86 waste-to-energy plants in 25 states, compared to over 400 waste-to-energy plants in Europe. Europe is leading the trend in sustainable plastic solutions, however there are leading states within the USA that are catching on to the waste to energy movement, such as Connecticut, Massachusetts and Hawaii. (8)  Surprisingly, California has one of the highest recycling rates, but one of the smallest waste to energy rates and ranks only 14 out of 50 states for avoiding landfilling.

 

The concept of waste to energy has been proven by many companies. There are about a dozen of these companies in the U.S. currently operating as well as overseas.

The waste to energy sector has received significant investment on research and technology.  An Oregon-based company called Agilyx received about $22 million from a group of investors which included the Waste Management Company and Virgin’s Richard Branson.
Most of the companies that were surveyed on these lists were asked specifically about using PLA and other biopolymers in their waste to energy process, and many of them stated that there shouldn’t be any difficulty or difference in using them as a part of their feedstock. (10)

The demand for bioplastics is expected to continue to grow due to such low market penetration of the global plastics market of approximately 1%. The projected capacity for bioplastics predicted for 2015 is 1.7 million tons. The expected gradual increase of crude oil and natural gas prices will allow bioplastics to become more cost-competitive with petroleum-based resins. (Soroudi, et al., 2013) Also, the move to more sustainable biopolymers has garnered international political support. “Japanese government directive requires that 20% of all plastics used in Japan to be bio-derived by 2020.” (Soroudi, et al., 2013)

The two prong approach of recycling and waste-to-energy is gaining momentum with new innovations and companies commercializing a variety of technologies to cope with the global plastic disposal problems.  International studies in communities that operate waste-to-energy facilities have shown that recycling rates increase.  In the U.S., in communities that have waste-to-energy facilities, the recycling rates are 5% higher than the national average representing a 40% increase in recycling. (11)

Conclusions   

Plastics offer compelling value and functionality and their usage and diversity will only increase over time.  There is a strong push to improve the sustainability and environmental footprint of plastics in general. The metrics used to compare these different approaches come back to evaluating the carbon footprint and the product’s life cycle.  Recyclability has been the most popular environmentally friendly disposal option, however its limited adoption restricts the potential of recycling to solve the plastic waste problem.

“Consumers believe that bioplastics are better for the environment due to sustainable feedstocks and the potential for reduced manufacturing and production impacts. Another key benefit is the potential to decrease our ecological footprint by creating additional end-of-life management options such as composting and closed loop recycling. In order to realize these benefits, however, product claims and performance must adhere to accepted standards, and consumers must be accurately informed about the proper disposal options of biobased plastic products.”(13) A closed loop system would allow the large volume commodity resins, when at the end of life of the durable product, to be collected and sent back for recycling into new material.  There’s a company called Ecospan, LLC that is a bioplastics company that has designed a bioplastics container that can be used several times in its repair and return cycle for electronics companies.  After several cycles, these containers are returned to Ecospan to be reground and made into new containers. Also, Schaffer Systems International has a fully enclosed loop system for their plastic bins used in various industries.

Perhaps the most promising approach is the two prong solution of recycle and waste-to-energy.  There is an opportunity to get involved and advocate for more of these facilities across the US.  Local government officials should be able to provide information about energy recovery in the various states. In 2008, Congress made the decision to ship 5,000 tons per year of non-recyclable waste Waste-to-Energy facility in Virginia.  In 2010 alone, more than 5300 tons of solid waste was collected from Congressional facilities, and this now will be converted to generate steam and electricity, instead of ending up in a landfill.  This is enough energy to power a Senate office building for several months annually. (12)   The potential exists for companies to participate more in depth with recycling of their products which has a substantial impact for both the producer and consumers.

 

 References

  1. American Chemistry Council’s Plastics Division Survey, November 2011
  2. Plastics Europe, Life Cycle of Plastics
  3. S. EPA Website, Municipal Solid Waste Generation Recycling and Disposal, November, 2011
  4. World Resources Institute-United Nations Division
  5. com, September 2013
  6. European Bioplastics, December, 2013
  7. American Chemistry Council, Plastics to Oil Study, 2011
  8. Canadian Energy from Waste Coalition, February, 2011
  9. American Chemistry Council, 2011
  10. American Chemistry Council, Plastics to Oil Study, 2011
  11. Government Advisory Services, 2009
  12. Roll Call, November, 2011
  13. http://compostingcouncil.org/admin/wp-content/plugins/wp-pdfupload/pdf/8095/Compostable%20Plastics%20101%20Paper.pdf
  14. Mosko S. The Problem With Plastic Are Bioplastics the Solution?. Natural Life [serial online]. January 2013;(149):17-21. Available from: Consumer Health Complete – EBSCOhost, Ipswich, MA. Accessed September 2, 2014.