End-of-Life
End-of-Life UW-Platteville portable 4-stage digester More Responsible By Debra Darby Director of Marketing Communications Mirel Bioplastics by Telles Lowell, Massachusetts, USA Today there is a cultural change that encourages consumers to minimize the use of plastics made from non-renewable resources like fossil fuels and to demand packaging that does not persist in the environment. Mirel bioplastics can help to reduce the amount of packaging waste sent to landfills and support alternative disposal sys¬tems including composting and anaerobic digestion. Managing the consumer end of the compost feedstock stream has its challenges because of the potential wide range of products going into the composition, but also because of how the local collection and processing infrastructure is set up to manage the mix of post-consumer materials. Working Toward Zero Waste and Energy Development Telles, a joint venture of Metabolix, Inc. and Archer Daniels Midland Company, is engaged in anaerobic digestion projects to evaluate the end-of-life management of Mirel (PHA) in packaging, food containment and agriculture uses, and to study how Mirel bioplastics mixed with these other materials aids in the conversion process of waste into biogas/energy. Earlier in 2010, the State of Wisconsin Office of Energy Independence (OEI) and UL Environment launched a pilot project to demonstrate the feasibility of manures, bioplastics and food waste in anaerobic digestion technology and to study the bio-energy contributions of bioplastics. The consortium involved a collaboration of stakeholders: government and agencies, bioplastics manufacturers, retailers and consumer groups with subtly differing interests. The project was designed to be modular and expandable across the state’s university system. Mirel has been shown to be anaerobically biodegradable. Last year Organic Waste Systems (OWS), Belgium, an independent laboratory, conducted a lab analysis to test Mirel materials according to the ASTM D5511 standard test method for determining anaerobic biodegradation of plastic materials under high-solids anaerobic digestion conditions. These test results at thermophilic temperature showed that Mirel bioplastics reached 100% biodegradation relative to cellulose control at the end of a 15- day test and generated more than 700 m³ of biogas per ton of material. Mirel materials produced five to six times more biogas than typical biowaste on weight basis, including food waste and municipal organic waste. Typically out of one ton of biowaste, about 120 m 3 of biogas can be produced. Tests at mesophilic temperature were continued to 42 days and showed that Mirel materials reached 78-99% absolute biodegradation. No Mirel was found in the extraction test of the digestate, which indicated the rest 40 bioplastics MAGAZINE [04/11] Vol. 6
End-of-Life End-of-Life Options Biodegradation % 100% 90% 80% 70% 60% 50% 40% 30% 20% of the Mirel materials had been converted to cell biomass. These findings suggest that even under mesophilic conditions Mirel materials are biodegradable. This test concluded that Mirel can be used to generate renewable energy through anaerobic digestion. Telles provided the OWS test data to the Wisconsin project to validate against their testing the inherent anaerobic biodegradability of Mirel. Over the last year, the University of Wisconsin – Platteville (UWP) research team led by Professor Tim Zauche and Dave Hitchins has studied the anaerobic digestion of bioplastics both at bench top scale and in a 750 Liter (200 gal) pilot scale portable digester unit. Their study evaluated mixed waste streams of dairy manure along with a variety of bioplastics and measured biogas productivity. The project was funded by the State of Wisconsin OEI and UL Environment. Early test results are indicating success of Mirel’s anaerobic biodegradability to generate biogas. Professor Zauche will be presenting the results from this pilot study at the BioCycle Conference in October 2011 in Madison, Wisconsin. With Mirel there are a multitude of more responsible end-of-life options. Mirel is 100% biodegraded in a 15 day test (according to ASTM D5511 standard test method for anaerobic biodegradation), meets ASTM D7081 (standard for biodegradation in the marine environment), and is Vinçotte certified OK Compost Home and OK Compostable. Biodegradation % 10% 0% 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 -10% 110% 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% XS-7/3 Ther Cellulose Avg XS-7/3 Ther P1003 Avg XS-7/3 Ther M2100 Avg XS-7/3 Ther F5003 Avg Mirel: Evolution of Biodegradation Percentage at ASTM D5511, 52±2°C 0% 0 7 14 21 28 35 42 -10% XS-7/5 Cellulosw Avg XS-7/5 M2100 Avg XS-7/5 M4100 Avg XS-7/5 P1003 Avg Mirel: Evolution of Biodegradation Percentage at modified ASTM D5511, 37±2°C www.mirelplastic.com XS-7/3 Ther M4100 Avg XS-7/5 F5003 Avg bioplastics MAGAZINE [04/11] Vol. 6 41
