Compostable Plastics: CHALLENGES & OPPORTUNITIES
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Compostable plastics: CHALLENGES & OPPORTUNITIES Dr. Love-Ese Chile Dr. Chile’s Biases and Values I’m a… Researcher Evidence-based decision-making Consultant Conversation, communication and collaboration Millennial Honesty, transparency, radical forward thinking We face global challenges. No time to wait, no time for waste. 3 Alternative visions for tomorrow 4 Regenerative Systems restore, renew or revitalize their own sources of energy and materials 5 Plastics have transformed how we live, work & eat 6 What makeso a plastic? Polymer = Greek for “many parts” Plastics are made from longo chains called polymers Polymers are made from singleo units called monomers All plastics are polymers BUT Not all polymers are plastics POLYMER DEFORMABLE? REFORMABLE? Plastics ✔️ ✔️ Rubbers ✔️ ❌ Resins ❌ ❌ Single use products and packaging – Often in contact with food and other organic matter making useful separation difficult Short term use products and packaging – Often in contact with liquids, gels, powders Plastics are COMPLEX Consumer products – EveryEveryday day products products Engineering plastics – Highly durable, made for specific applications Food Loss & Waste 28% of food is wasted each year 35.5 million • Major economic losses metric tonnes • Wasted natural resources of food waste: • GHG increased for no value Planned Packaging reduces food waste by: Unplanned • Maintaining freshness, nutritional value and safety 32% 68% • Efficiently containing and protecting • Delivering portion control and resealability Gooch, M., Bucknell, D., LaPlain, D., Dent, B., Whitehead, P., Felfel, A., Nikkel, L., Maguire, M. (2019). The Avoidable Crisis of Food Waste: Technical Report; Value Chain Management International Environmental impacts of plastic packaging • 40% of plastics produced globally are used in packaging • Often too difficult to sort & clean; only 14% collected for recycling Ellen McArthur Foundation, 2016. “The new plastics economy. Rethinking the future of plastics.” Ellen McArthur Foundation. https://www.ellenmacarthurfoundation.org/publications/the-new-plastics- economy-rethinking-the-futureof-plastics Helena Dahlbo, Valeria Poliakova, Ville Mylläri, Olli Sahimaa, Reetta Anderson, “Recycling potential of post-consumer plastic packaging waste in Finland”, Waste Management 71 (2018) 52–61 Bioplastics: bio-based, biodegradable, plant-based, or compostable? 14 Plastic feedstocks Bio-based AKA bio-sourced, ideally using renewable resources: • Primary feedstocks • Secondary feedstocks • Petroleum feedstocks Prata et. al., “Solutions and Integrated Strategies for the Control and Mitigation of Plastic and Microplastic Pollution.” https://doi.org/10.3390/ijerph16132411 Prosperi et.al., “Production of bioplastics for agricultural purposes: A supply chain study.” https://dx.doi.org/10.3280/RISS2018-001010 Plastic feedstocks Bio-based AKA bio-sourced, ideally using renewable resources: • Primary feedstocks • Dedicated crops: • Corn, rice, wheat, etc. • Secondary feedstocks • Petroleum feedstocks Plastic feedstocks Bio-based AKA bio-sourced, ideally using renewable resources: • Primary feedstocks • Secondary feedstocks • Waste valorization: • Lignocellulosics from wood • Used cooking oil • PHA produced by bacteria consuming glucose from wastes • Petroleum feedstocks Plastic feedstocks Bio-based AKA bio-sourced, ideally using renewable resources: • Primary feedstocks • Secondary feedstocks • Petroleum feedstocks • Production of conventional plastics • Emerging plastics like PBS produced from fossil fuels “Bio-based” vs. “Biodegradable” ‘Bio-based’ = origin of the plastic ‘Biodegradable’ = breakdown of the plastic A plastic being fossil- or bio-based, does not determine if it’s biodegradable No North American certification standards for bio-based products Bio-based plastics Thermoplastic starch (TPS) and starch blends Moisture-sensitive and brittle PHA (polyhydroxyalkanoates) Produced in the microbial cells through fermentation, then harvested PLA (made from corn) Most well known compostable plastic Bio-based PE and PET Same chemical and physical properties as their fossil-based counterparts PBS = polybutylene succinate Fossil-based, Fossil based w/ high strength compostable PBAT = polybutylene adipate terephthalate plastics Industrially compostable w/ high strength FEEDSTOCK Bio-based Bio-based bio-PE, bio-PET PLA, TPS, PHA, bio-PBS Biodegradable LIFE Recyclable - OF - Landfilled Biodegradable END PBAT, PBS Fossil-based Fossil-based End-of-life options Using additional or enhanced disposal options: • Composting • Anaerobic digestion • Chemical recycling • Mechanical recycling • Biological recycling • Use as animal feed (in some cases) • Feeding small amounts of PHA to shrimp and other aquatic animals, can improve growth and survival rates Gao, M., Du, D., Bo, Z., Sui, L., 2019. Poly-beta-hydroxybutyrate (PHB)- accumulating halomonas improves the survival, growth, and robustness and modifies the gut microbial composition of Litopenaeus vannamei postlarvae. Aquaculture 500, 607–612. Recycling bioplastics • Recycling of compostable plastics, technically possible but practically difficult • Bio-based plastics, such as PLA, cannot be recycled together with conventional plastics. • Recyclers have to guarantee the quality of recycled polymer materials • Complicated by: ➢ Confusing labelling ➢ Unknown additives and blends ➢ Degradation by heat and water • Leads to downcycling and loss of material value e.g. bottle-to-textiles Aerobic digestion (with oxygen) - produces compost/soil Biological recycling Anaerobic digestion (without oxygen) - produces energy/fuel - high methane potential “Biodegradable” vs. ”Oxo-degradable” vs. “Compostable” ‘A material degraded by the action of microorganisms and ultimately converted to water, carbon dioxide and/or methane and new bacterial biomass. Conventional plastics such as polyethylene (PE) which include an additive designed to help them break down and fragment Certified compostable products, breakdown under specific conditions in specific time frames. Standardized tests vs. Certifications Standardized test method - general measure of compost biodegradation, designed to yield reproducible and repeatable test results Certifications verify that products and packaging have been independently tested according to scientifically based standards There are many standardized tests in this space, but in North America only industrial composting certifications are available. Industrial Compost Certifications Only available to food service items, food packaging and yard waste products Industrial Compost Certifications ● 90% disintegration within 12 weeks ● 90% conversion to CO2 within 26 weeks ● Heavy metal and PFA analysis ● Plant germination toxicity ● Soil invertebrate toxicity However, industrial composting plant have: ● an active phase for 3-6 weeks ● post-composting stabilization for 8-12 weeks Composter acceptance of food service products (FSP) Commonly accepted compostable products: 1. Paper carryout bags 2. Uncoated food soiled paper like napkins, towels and some plates 3. Compostable plastic bags 4. Molded fiber take‐out containers 5. Corrugated containers like pizza boxes 6. Coated food soiled paper like cups and take‐out containers 7. Compostable plastic cups, plates, take‐out containers and cutlery Foodservice Packaging Institute, “Foodservice Packaging & Composting: Information for Composters” Quickly degrading polymers Pass/Fail Certifications* *No indication of Slowly degrading polymers how fast products will break down Narancic, T.; Verstichel, S.; Reddy Chaganti, S.; Morales-Gamez, L.; Kenny, S. T.; De Wilde, B.; Babu Padamati, R.; O’Connor, K. E., Biodegradable Plastic Blends Create New Possibilities for End- of-Life Management of Plastics but They Are Not a Panacea for Plastic Pollution. Environmental Science & Technology 2018, 52 (18), 10441-10452 Laboratory tests How viable are should be coupled laboratory tests? with field tests Mature compost Food waste, yard waste Individual components Whole product TESTING Fluctuating temp. Optimal temp. and humidity CONDITIONS and humidity Simplified environment Complex environment Ideal conditions for Variable conditions for biodegradation biodegradation Haider, T.; Völker, C.; Kramm, J.; Landfester, K.; Wurm, F. R., Plastics of the future? The impact of biodegradable polymers on the environment and on society. Angewandte Chemie International Edition 2019, (58), 50-62. Field test performance Adding compostable food service packaging (FSP): • No effect on the biochemistry or nutrient value of finished compost • Acts as a bulking agent similar to wood • Active composting often extended beyond typical operational time-frames; stringent pile management implemented Compost Manufacturing Alliance: Testing to determine the breakdown of products using modern, large-scale compost manufacturing technologies Compost Manufacturing Alliance https://compostmanufacturingalliance.com/ Foodservice Packaging Institute and Biodegradable Products Institute, “ Field Study: Foodservice Packaging as Compost Facility Feedstock.” 2018 Challenges with adding plastic into organics composting Definitely challenges ahead but also many opportunities. With conversation and collaboration, we can create a system that works. So…compostable plastics? Questions? Queries? Quandaries? Dr. Love-Ese Chile GreyToGreenSolutions.com LoveEseChile.com If the future can be positive, why choose differently? - Michael Braungart, Cradle to Cradle Design About the speaker My name is Ese. I'm a Change-Maker, Researcher and Educator. With the help of community groups, I put together workshops and forums to start conversations about sustainability and green technologies. To connect with me further and to help continue the discussion, find me at LoveEseChile.com or GreytoGreenSolutions.com.