Last month’s Advanced Degrees column focused on the facts and myths about expanded polystyrene (EPS). This seemingly ubiquitous plastic, whose cushioning properties, insulation performance and cost often exceed any alternative packaging, is frequently maligned for its consumption of energy to produce and its overall post-use impact on the environment. Still, one inevitable question remains: what to do with it once it has served its purpose.

            Currently, there are only a few, limited options: burn it, recycle it, or bury it.

            There is energy to be recovered from post-consumer use of EPS in the form of heat from incineration. EPS has a high caloric value – slightly more than that of coal, and it burns much, much cleaner. But the practicality of incineration programs has never been implemented on a scale to move the environmental impact needle, as costs for collection, segregation, and transportation to incineration sites have made this option an economic loser.

            Recycling EPS ranks considerably higher than energy recovery among the ecologically conscious, and in less than two decades the US has gone from 0% recycling to nearly 20%, or 57 million pounds of EPS annually,[i] 10-12% of which is post-consumer material. The total annual rate is even higher in Europe; 35% in 2006.[ii]

            Recent technological advancements such as EPS densification systems have helped to improve the economic viability of recycling programs mired in operational costs by compacting it to about 40 lbs./ft ³ (as opposed to its normal 1-2 lbs/ ft.³) before recycling or incinerating. Densified blocks are shipped to re-processors around the world. A few companies reprocess the EPS into a resin by reheating and extruding it and infuse it into other resin as partial recycled content for a new piece. However, this is not achieved without substantial operational, energy, and environmental costs.

            The problems associated with most recycling programs involve the costs of reverse logistics; getting the material back to a location and staged for its next use. The biggest culprits are transportation costs and energy consumption and their respective environmental impacts.  

            In an effort to countervail this problem, the Alliance of Foam Packaging Recyclers (AFPR) announced in September, 2008, its expansion of the national mail-back recycling program. It provides a mail-back opportunity for the public where no recycling programs exist in their community. The EPS packaging industry is the only industry providing public mail-back recycling. The expansion program has gone from one site in Maryland to 34 sites in 20 states and is utilized by hundreds of individuals, companies and organizations including: hospitals, pharmaceutical companies, schools, and college research facilities. To facilitate shipping, the United States Postal Service provides the convenience of having the shipment picked up by local USPS carriers as outbound mail which helps to minimize environmental impacts associated with transportation. The cost for mail-back is the responsibility of the sender and varies depending on volume. Consolidated in a corrugate box, the recyclable material shipping costs are typically between $1.50 and $9.00, according to AFPR.[iii]

            Once the material reaches the nearest recycling location, its volume is reduced by as much as 50% by pre-breaking. It is then re-introduced as regrind into the manufacturing process and incorporated into new products, or it is resold to other facilities.

            Despite all the recycling and reuse efforts, inevitably, nearly all EPS, like most other materials, meets its end-of-days in a landfill.

Pardigm Shift  

            Most people think of recycling with short term gratification, and the immediate positive impact they are making on their personal environment in particular and to the global environment in general. But there is a movement afoot by industry which is looking beyond making new coffee cups, coat hangers, and flower pots from recycled EPS, whose scale is much broader, benefits more sustainable, and energy reduction far more impactful, than traditional recycling methodologies.

            The process is called by-product synergy, where carbon off-sets (a term meaning CO₂emissions cancelled from the environment) result by incorporating the waste product or by-product of one process or material, as the raw material for another, completely unrelated process. It is not a new concept by any means. Take iron slag for example. Slag is a low-grade metal by-product accumulated in blast furnaces when making molten steel. Mountains of the stuff surrounded steel mills. It was an ecological disaster. But granulated and mixed with cement, slag has found new life in sub-sea oil and gas drilling applications. Even Cream of Tartar, the waste sediment produced in wine-making has found useful applications in kitchens as a stabilizer in baking, and is used to produce a smooth texture in everything from commercial soft drink recipes to photography paper. It even cleans brass and copper cookware.

            Now certain manufacturers and users of EPS are collaborating on a pilot by-product synergy program using EPS. Instead of thinking about its first use application and subsequent disposal, they are concentrating on its second use. They are asking themselves these fundamental questions: What happens after the initial post-consumer application? How can this material be applied so that its second use is actually more virtuous than the first? How can the first use of EPS be the catalyst for a long-term sustainable second time, energy saving use? These questions present an interesting paradox: the more worthless (in value) and environmentally problematic the material is after its initial use, the more valuable it is to the viability of the second application. Its value increases by creating a secondary market which provides a long-term benefit to the environment, rather remaining environmentally neutral, or worse.

            This can be achieved with EPS by funneling it back into a process different than making a new cup or container. However, creating and using the material initially is a first and necessary step. But no longer are first use consumers of EPS contributors to the “problem,” but rather feeding the solution. As an alternative to the existing methods of recycling, (such as pre-breaking and densifying EPS), one promising high-volume EPS by-product synergy is in building technology. By mixing a very high ratio of post-consumer EPS with concrete, along with a small portion of other binding materials, a new form of interlocking concrete block is created. Their composition and application produce a very strong, highly insulated building envelope. Such blocks (which may be comprised of as much as 90% EPS and 10% concrete) can be used to make houses, commercial buildings, retail stores, schools, hospitals, and hotels. The key difference is that every other insulation program for buildings uses virgin material, not post-use EPS. Recyclable EPS is so abundant and readily available that such a program is immediately viable. The long-term upside is that buildings employing this technology are incredibly energy efficient. The blocks are 40% lighter than traditional concrete or cinder blocks, requiring less fuel and energy to transport.

            It is surprising to many to learn that more energy is used annually by buildings than cars and that most CO₂ emissions are created not by trucks and autos, but by the normal, everyday operation of buildings through heating, cooling, and lighting.  Reducing the use of energy in buildings is one of the most important places to look for the reduction of energy.

            A typical application of a composite cement and waste polystyrene block single-family home is calculated to have a 50% energy savings over the life of the building vs. traditional building materials, which equals 6 metric tons of CO₂ per year. Each home saves about 41 trees which would normally be used to construct a traditional “stick-built” home, offering additional benefit where lumber is scarce, expensive or undesirable as a building material. A composite block building’s superior insulation properties can provide additional savings in areas of extreme climates. Instead of adding insulation to the walls, the walls are the insulation. Their strength is advantageous in locations where hurricanes and damaging winds are prevalent – providing additional protection and helping to reduce insurance and replacement construction costs. Each composite block home keeps 2,477 lbs. of waste polystyrene out of the landfills and requires 40% less concrete to build, which eliminates 25 additional tons of CO₂ emissions.Construction costs are currently 3-4% higher than that of traditional houses, with the price projected to decline as volume increases.

            What about the age-old problem of reverse logistics? Programs are in development to collect waste EPS from high-volume, first use locations at no cost. And there are plenty of candidates. Wal-Mart ^®for example, conservatively estimates that it generates about a million pounds of waste EPS a month from its more than 4,000 stores,[iv] and there is an abundance of it generated by the healthcare and electronics industries as well. Inexpensive equipment may be provided at no charge to facilitate the process at high-volume users and negotiations are underway with major transportation providers to reduce the transportation and energy costs to participants, and make the program viable, if not profitable for all parties. Profit is not a term generally associated with recycling. The unfortunate reality in any recycling program, whether it is a traditional concept or a by-product synergy plan, is sustainability. It is difficult to maintain if it is economically undesirable or places a burden of inconvenience on its participants. Such short-sighted goals need to be reevaluated with the paradigm shift to the long-term benefits and programs such as sustainable recycling and reuse. The high visibility of EPS waste issues can be a great place to start.