A new study confirms that recycling plastics, specifically PET and HDPE, results in significant savings in energy and greenhouse gas emissions. The study used life cycle inventory (LCI) methodology to quantify the energy requirements, solid wastes and, atmospheric and waterborne emissions for the processes required to collect post-consumer PET and HDPE packaging, sort and separate the material, and reprocess it into clean recycled resin.

Based on the LCI study results and data from U.S. EPA, the generation of cleaned recycled resin required 71 trillion Btu less than the amount of energy that would be required to produce the equivalent tonnage of virgin PET and HDPE resin. In other words, the amount of energy saved by recycling PET and HDPE containers including bottles in 2008 was the equivalent to the annual energy use of 750,000 U.S. homes. The corresponding savings in greenhouse gas emissions was 2.1 million tonnes of CO2 equivalents, an amount comparable to taking 360,000 cars off the road.

(Calculations were based on the tonnage of post-consumer PET and HDPE recovered in 2008, and the energy required to collect, sort and domestically reprocess the tonnage of plastics containers (including bottles) recovered in 2008.)

The new study, ‘Final Report – Life Cycle Inventory of 100% Post-consumer HDPE and PET Recycled Resin from Post-consumer Containers and Packaging’, conducted by Franklin Associates Ltd., was jointly sponsored by the American Chemistry Council (ACC), the Association of Post-consumer Plastic Recyclers (APR), the National Association for PET Container Resources (NAPCOR) and the PET Resin Association (PETRA).

Life cycle inventory studies involve the compilation and quantification of inputs and outputs for a given product system throughout its life cycle. A typical LCI looks at the total energy use, greenhouse gas emissions and waste generated from raw materials extraction through manufacturing, transportation, use and disposal or recycling.

In 2007, the American Chemistry Council (ACC) sponsored a ‘cradle-to-resin’, or ‘cradle-to-gate’ LCI for nine plastic resins and two polyurethane precursors that examined current data to quantify the total energy requirements, energy sources, atmospheric pollutants, waterborne pollutants and solid waste resulting from the production of commonly used plastic materials in North America. The data collected for the 2007 study are publically available online through the U.S. Lifecycle Database, a project of the U.S. Department of Energy and its National Renewable Energy Laboratory (NREL). The 2007 report is available on ACC’s website (see: http://www.americanchemistry.com/plastics/sec_content.asp?CID=1930&DID=7832).