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Packaging End-of-Life Options Other Than Recycling

Posted on 1/22/2014 1:51:44 PM By Jeff Timm
  

End-of-life (EOL) options other than solid waste land-fill have been a major topic in the world of packaging for a number of years.  Most businesses and consumers realize and accept the fact that solid waste material in a landfill is a poor use of resources.  This is this a poor use of resources due to the fact that recovery and reuse of these resources is forever lost when this material is entombed in the earth.  It also requires much effort to collect, sort and manage solid waste in land-fills.  Most of past discussions have focused on single or mixed-stream mechanical recycling issues with a secondary but waning focus on packaging biodegradability as an EOL option.  Besides these two major options in the cradle-to-cradle life cycle loop there are lesser known technologies and processes that are in various developmental stages or fully commercialized in the marketplace.

These additional technologies/processes are:

  • Aerobic digestion
  • Anaerobic digestion
  • Incineration
  • Plasma arc
  • Thermal depolymerization
  • Gasification
  • Pyrolysis

While all the above have merit in dealing with packaging end-of-life options, some are better suited for plastic vs. paper or organic waste.  One of these, pyrolysis, is beginning to gain traction in dealing with packaging plastic waste specifically with multi-layer plastic film packaging.  This process falls under the broad category of ‘waste-to-energy’ (WTE).  Energy recovery is the process by which solid waste is converted into feedstock materials or renewable energy.

Pyrolysis is sometimes confused with gasification and incineration—“mass burn.” It is not incineration, although both achieve degeneration from heat for the process to work.  Incineration is usually associated with the energy recovered in the process in the form of heat (steam) to drive energy creation like electricity.  Pyrolysis is the recovery of the materials building blocks and oil.  In the marketplace, incineration is often referred to as WTE or ‘recycle-to-energy,’ partly because that is exactly what it accomplishes.  But WTE is a new descriptor used due to the negative social stigma the term incineration has historically garnered as a result of overall poor environmental stewardship.  It should be noted that municipal incineration facilities today are safe.

Pyrolysis is an endothermic, chemical-decomposition (cracking) of organic material (carbon based) at elevated temperatures in the absence of air or oxygen.  There is no burning.  The end result of the process is the physical and chemical phase change of materials from which are derived building block monomers and/or smaller hydrocarbons such as methane, ethane, carbon monoxide (CO), hydrogen (H2) and char. 

Pyrolysis is also often associated with gasification, which is an endothermic process of converting organic or petrochemical based materials into CO, H2, carbon dioxide (CO2) and methane.  The reaction occurs at elevated temperatures without combustion with a controlled amount of oxygen and/or water (steam).  The end product of gasification is ‘syngas’ (CO + H2).  Slag and ash are created as by-products.

Source: ASTM International

Source: Flair Flexible Packaging Corp.

Multi-layer film packaging

So why is multi-layer film packaging a candidate for the pyrolysis recycle/recovery process?  First, one must understand what a municipal solid waste recovery facility (MRF) considers the ideal recovered plastic material. MRFs receive the highest value by separating their intake mixed streams into single plastic types.  For example, this means separating all the various plastics like high density polyethylene (HDPE) from polypropylene (PP) or polyester (PET) and so forth.  The recycled material value rises the higher the percent of contamination-free plastic material achieved.  Other plastics or additives mixed in with a single plastic stream are considered contamination.  Since it is not technically feasible to separate the sometimes up to 9+ layered packaging film structures into their individual plastic types due to the laminated or co-extruded tie layer joining adhesives employed, an alternative EOL option is appropriate. Because of these separation difficulties, there is little or no value for mixed component multi-layer plastic film products in mechanical recycle operations.  The mechanical recycling operation of mono-layer plastic film articles is growing quickly and has higher value in the recovery of these materials.

It is not that multi-layered packaging film structures represent a small opportunity.  The Bemis Company, Neenah, WI, North America’s largest packaging film converter, estimates that, on average, 60 lbs. /yr. of multi-layered packaging film are used by every U.S. residence.  Like most recycling opportunities, the packaging industry--through programs driven by companies like Bemis--targets large cities where collection within a manageable geographic area is feasible to gain critical mass.  According to a new report from PCI Films Consulting Ltd., Guilsborough, England,  the total flexible film packaging market, of which multi-layer film offerings are a major component, will grow into a $25 billion business in North America during the next five years. The market totaled $20.7 billion in 2013, with 88% from the United States, 7% from Canada and 5% from Mexico. North America represents about 30% of the global consumption of flexible packaging and is projected to grow at 4% during the next five years.

nestle crema, crema de leche, nestle crema de leche

Source: Bemis Company

Bemis identifies the ideal multi-layered film packaging material suitable for pyrolysis as any substrate with a high carbon level.  Polyethylene and polypropylene are the two polymers with the highest level of carbon commonly used in film packaging.  They represent a 80-85% yield in the pyrolysis process.  Nylon and PET represent the lowest yield materials in this process at ~40% yield.

There are still huge barriers to this type of EOL option being fully embraced by consumers and even the WTE and packaging industries themselves.  Here are some:

  • Marketplace awareness of the collection opportunity needs development
  • Continued development of the pyrolysis and other WTE processes is needed
  • The establishment of a viable collection and sorting of post industrial and post consumer multi-layered film packaging material is a challenge

Establishing a viable collection process where multi-layered, 2+ different material substrates are used has a unique hurdle to overcome.  Multi-layer film packaging articles utilize the #7 Resin Identification Code (RIC), the familiar number code inside the chasing arrows employed on plastic items. 

RIC, RIC other

Source: ASTM International

The #7 RIC means “other,” a catch-all designation which indicates the resin employed is not #1 through #6 or the resin is a compound, blend, or inseparable combination of multiple resins.   The #7 RIC designation, in practice, has led to the belief that the material is not recyclable, when in fact, many curbside recycling programs do not allow plastic articles with the #7 RIC designation.   Companies trying to promote a favorable consumer image by using recyclable materials in their packaging try to avoid designing a product utilizing materials which will be coded with the #7 RIC designation.  Hopefully, the packaging performance functional requirements dictate the materials of design. The multi-layer package design is often necessary for the package to achieve all the performance requirements, something that a mono-layer design cannot deliver.  The pyrolysis process changes this EOL paradigm for multi-layer film packaging recovery.

Another positive development in the WTE field is the recent establishment by the American Chemistry Council (ACC) of a new group formed within its Plastics Division that will work to enhance public policy in support of technologies that convert non-recycled plastics into petroleum based products. The new Plastics-to-Oil Technologies Alliance will work to increase awareness of the benefits of plastics-to-oil technologies, enhance the voice of the industry through expanded membership and demonstrate broad support for plastics-to-oil technologies through an expanding network of allies.

Founding members of the group include Agilyx Corporation, Beaverton, OR, Cynar Plc, London, England and RES Polyflow, Akron, OH.  Membership is open to entities that develop and implement technologies to convert non-mechanically recycled plastics into petroleum and petroleum-based products like aromatic components.

It is clear that plastic recycling was one of the top packaging industry stories for 2013.  If industry trade associations like the ACC, packaging companies like Bemis and others engaged in the plastic film value chain can drive programs to increase recovery of multi-layered plastic film packaging, perhaps WTE will be the top packaging industry story in the very near future.

Thoughts?



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