|Plastics from plants threaten recycling|
PLA in bottles could significantly undermine recycling's economics by disrupting successful PET recovery programs and by losing the high value in the PET bottles it displaces.
Petition to NatureWorks
are bio-based plastics?
impediments to economically recycling PLA
are bio-based plastics?
A material recovery facility, or MRF, is where commingled recyclables, including many PLA bottles, are sorted. MRFs usually will only incur the cost to bale and ship any sorted PLA bottles to such a facility if it expects to receive adequate revenues in return to justify the expense. However, the few industrial composting sites that exist would typically be far away. They would be expensive to ship to, and, in the end, compost facilities charge rather than pay feedstock. This would be even more the case for PLA, which appears to primarily break down into carbon dioxide and water, but not leave any nutrient value to return to the soil. In most cases, landfilling the PLA bottles, along with the other rejects and residuals, would be less expensive for the MRF.
It is difficult to conceive of any real world circumstance, other than possibly at a few large controlled events where dedicated collection bins are provided, in which any PLA bottles that were separated would not be landfilled, instead of being composted. Composting PLA bottles may be an admirable goal when compared to landfilling, but it is an abstraction not likely to become a significant reality for PLA bottles. It is also, as discussed below, not as desirable as reducing, reusing or recycling.
In addition to the Plastic Redesign Project, the Container Recycling Institute, Eco-Cycle, the Ecology Center, Eureka Recycling, the Grassroots Recycling Network, and the Institute for Local Self Reliance, have joined together to call for a moratorium on PLA in bottles until the major recycling problems, which are detailed below, can first be resolved.
On the other hand, the recycling groups have no problem with PLA in other applications like food service ware, which have no existing recycling infrastructure that would be disrupted, and believe that there could major benefits from a shift to a carbohydrate economy if the transition properly managed.
(1) Lower on
(3) Contamination of PET stream
Separating PLA bottles from the PET bottles, with sufficient accuracy for the high value end markets, has not yet been demonstrated when present above trace levels, and the hurdles to practically doing so in the future will not be overcome easily.
First, like PET, PLA is clear, which makes visual identification impossible. Some have proposed that updating recycle codes to recognize PLA could resolve this problem, but that is not likely to be the case. In most states, each plastic bottle that is larger than 8 ounces is required to have a number code from 1 to 7 stamped onto the bottom, which is a system that was developed by the Society of Plastic Industries (SPI) in order to designate which bottle is high density polyethylene (HDPE), PET, polypropylene (PP) and so on. Creating a new SPI number for PLA would not be much use since neither MRF's, nor intermediate processors who upgrade sorted bottles, identify resin by having sorters lift up each bottle to look at the number on the base. The bottles literally fly by on conveyor belts too fast for detailed inspection often at more than 1,000 bottles each minute.
Then, simple, low cost, automated sorting methods, which are based upon the fact that some resins sink in water while others float, also are not an option here. Water based sink-float tanks can inexpensively separate lighter-than-water plastics, such as the HDPE used in milk jugs, from heavier PET, which sinks. But PLA, like PET, is also heavier than water, which means that they would both sink in the tanks.
For this reason, expensive and complicated optical sortation systems will almost certainly be necessary, Optical sorters work by using specific wave lengths of light that excite or absorb electrons of different resins differently, and thereby reflect the light in unique patterns that can be distinguished by diodes. PLA has been found to have a distinct "signature" from PET under near infra-red light(IR), which should make optical sorting possible.
But, there are four obstacles to its realization, including [i] the existing system will be inadequate, [ii] some processors do not presently use any optical sorters, [iii] those that do usually use X-ray, not infra-red, systems, and [iv] even if a conversion to an adequately improved IR system is accomplished, the recycling infrastructure will have to bear an additional sorting cost–
There is a key distinction among these sorts of buy-back rates that must be understood to evaluate their utility. On the one hand, in the best case, there may be offers that provide a kick-start to leap over a short-term transition to a future-world where PLA will make economic sense after a carefully developed plan is fully implemented.
On the other hand, there are offers that are essentially "teaser rates," which do not have an sustainable economic rationale. A well-known example are the offers for three month no-interest credit cards that revert to high rates immediately afterwards. These only last until their short term purpose of winning a customer, or, in this case, facilitating market entry among "green" consumers, is served. Afterwards, they are quickly withdrawn. For there are not many profit-making enterprises that willingly chose to lose money for very long. Examples of this teaser-rate type of buy back offer include Oxychem's offer to purchase recovered PVC bales in the early 1990s, which was cancelled after the threat of legislative PVC bans had passed. In 2002, Continental PET Technologies offered to buy back its barrier enhanced plastic beer bottles. That offer was cancelled a year after the bottle entered the market but stalled out.
A buy-back program cannot substitute for the absence of any strategy to develop an ultimately economically sustainable system. Meaningful buy-back offers only serve as a short term transition to a valid one that has been proposed. To the extent that offers without any economic basis lull consumers into thinking something constructive is being done, they can actually undermine efforts to encourage real progress.
At present, NatureWorks is still in the process of developing a plan, but does not yet have any specific proposal to present to recyclers to evaluate.
Are NatureWorks' other assurances about PLA's trace presence adequate to protect recycling?
There are three issues involved in answering this question. The initial one is (1) how small a concentration of PLA in PET bottles creates problems for recycling the PET. The second is (2) how likely are we to cross that threshold in the foreseeable future. Lastly, (3) what will be the impact on recyclers when that threshold is crossed.
(1)The threshold of concern
Even if a major investment is made in new optical sorting equipment in an attempt to remove enough PLA bottles to bring the residual PLA in PET bales below one in one-thousand, that will soon still not be enough. At the 97.5% accuracy rate that NatureWorks reports infra-red sorters achieves in careful trials, PET bales would be rejected by bottle markets when there is just 4% of the clear plastic bottles made from PLA(see table below).
Furthermore, in practice, the national average percent of PLA in bottles will not drive the result. Instead, the actual threshold to cross where PLA unacceptably contaminates PET will vary in different parts of the county. And since most bottles are marketed nationally, the conditions in the area of the country with the greatest sensitivity will define the limiting condition – not the average for the U.S.
Water and fruit drink bottles, which is where PLA would be found, will be sold and collected in different proportions to PET bottles in different regions. In states with expanded deposit laws that cover these non-carbonated bottles, PLA would wind up in the recycling stream at far higher rates than in deposit law states limited to soda bottles. Similarly, regions where people are more health conscious and affluent will consume far greater proportions of water bottles, where PLA will be far more concentrated, than elsewhere where PET for soda bottles will be more prevalent. Thus, projections of average saturation levels have the potential to seriously disguise far greater localized impacts that will arise and effectively determine maximum acceptable PLA volumes.
(2) The growth prospects for PLA
At present, PLA is more expensive than PET, and it is largely limited to niche markets appealing to “green” consumers. These are the 5%-20% of the population who are willing to pay more for products or services that they believe will have less impact on the environment. However, if petroleum prices rise dramatically, similar to what happened in the summer of 2006, then PLA would presumably become less expensive than PET bottles. The graph along side demonstrates how substantial an impact the 2006 gas run up had on ethanol production.
The similarly overwhelming influence of energy prices on PLA's prospects can be seen by the fact NatureWorks manufacturing facility in Blair, Nebraska, sat woefully underutilized following its opening in 2002 until the dramatic increase in oil prices during the summer of 2006. Prior to that time, NatureWorks was reported to be close to shutting its doors. Since then, the plant has been reported to be oversubscribed, with more demand than it can meet, notwithstanding the subsidence in oil prices later in that year.
With the next sustained price hike for oil, one would anticipate a very rapid conversion of PET to PLA for those applications where it provides suitable performance characteristics. This dramatic shift in growth rates is often represented by the called “S-Curve” that is used to describe the pathway of new products into the market. In the beginning, the initial purchasers are few, being limited to early adapters and niche markets. But that is followed by a second phase of high growth as the product becomes cheaper and gains widespread acceptance. Later, the product saturates its market and moves onto a slow growth mature phase, completing the top of the "S" (see the graph along side showing how saturation increases on the y-axis at different rates over time on the x-axis). We have all seen this in the past in such things as the seemingly overnight conversion from glass to plastic 2 liter soda bottles or from vinyl to CDs, as we will, in the near future, in the conversion from cathode ray tube to flat screen television.
Thus, the fact that current demand for PLA in bottles is too small to be of concern is seriously misleading. Today's trace levels are completely unrelated to PLA's enormous growth prospects when the oil markets surge once again.
Depending upon when the next run up in petroleum prices occurs, recyclers will almost certainly then suddenly find themselves with large volumes of the new incompatible bottle on their sorting lines – and in volumes that are significantly larger than the initial trace amounts found today. That would both contaminate the PET that the MRF wants to recycle, and also lose the high value of the PET bottles that are displaced by PLA.
(3) The impact on recyclers
But, then, while too large to be ignored as a contaminant in the PET bales, the PLA volumes may not be large enough to sustain a recovery infrastructure of its own. Because PLA has not yet been enhanced to retain carbonation, it might have an inherent constraint on its maximum share in the market. That could prevent it from ever reaching the necessary threshold to be recycled at all.
And even if it did reach that critical mass, no recycle market has yet been found to sell PLA into. Finally, even if one were, it is not apparent whether such a new recycle market for PLA would pay anything like the handsome prices returned by the PET markets. At best, even if all of these hurdles were overcome, that could still lead to substantial revenue shortfalls that would require new unpopular taxes to meet.
Thus, in the absence of a moratorium, after PLA has gone into full bottle production, recyclers could then be confronted with the fact that doing so severely disrupts recycling markets. But, by that time, so many investments and commitments to support that bottle will have been made that, it could be too late to "put the genie back in the bottle."
This is not meant in any way to imply that the problems that PLA bottles currently pose for recyclers cannot be overcome. They may well be. But the hurdles are not insignificant. Clearly, a concerted effort will be needed to find that pathway to success. Removing the pressure to devote the requisite resources to the task by prematurely rushing bottles to market does not appear to be the best way to constructively focus the company's energy on the major problem-solving work ahead.
But, for that workaround to be constructively pursued, NatureWorks, and other manufacturers of bio-based resins, ought not introduce their resins into the bottle market until after these problems have been resolved.
A Some consumer product and package companies have acted as if they are entitled to introduce any new package into the marketplace that maximizes their sales objectives, and recyclers will just have to find a way by themselves to deal with any ensuing problems.
Not only is that misguided belief no longer acceptable to recyclers, but also, it is fundamentally incompatible with the very free market principles that they espouse to support their laissez-faire beliefs.
Free markets are said to be the best way to balance the supply with demand for the things that people want. Using the marketplace to neutrally arbitrate between buyers and sellers in this way is thought to optimize overall human happiness.
However, for that to actually happen, the price of making something needs to reflect all of the costs that go into making it. Otherwise, its price will appear artificially cheap, and more people will buy it than they otherwise would if it were priced higher in order to capture all of the costs associated with its production.
Too often, the price we see only reflects the costs on the books of the manufacturer. Ignored are costs the company may impose on society-at-large, such as when pollutants are emitted from the smokestack at the factory where the product is made that causes the neighbors to become sick and die prematurely. If the company is allowed to continue polluting, it will be able to sell more goods because of its artificially low price. That will inflict more pain on the firm's neighbors than would have been the case if the goods reflected all of the costs its production caused.
When government passes regulations to protect innocent members of the public from being harmed by the production of things other people want, it does not violate economic principles. To the contrary, it makes it possible for the free market to function as intended by sending the correct price signal about how much things really cost.
In this case, some companies do not want their package branded as non-recyclable, because that might adversely affect sales, but they do want someone else, which winds up being the taxpayer, to pay the additional costs to recycle their especially hard-to-recycle packages. That warped view of the world bears no relationship to proper market principles, under which this sort of subsidization would not occur.
Absent a moratorium, today’s vibrant plastic recycling markets could be seriously disrupted by PLA bottles, and that would undermine the economics of curbside recycling programs. That would leave the taxpayer to subsidize new ill-considered packages, which fail to contemplate how their end-of-life can be sustainably handled.
A You can click here to sign onto the Petition to NatureWorks and join with many other organization who are urging the company for a moratorium on any more PLA bottles until these recycling issues have been resolved.