Bioplastics

9 04 2012

The first plastic garbage bag was invented by Harry Waslyk in 1950.

1950!  Mr. Waslyk could not have predicted how much havoc his plastic child would wreck in a mere 62 years.[1]

We’ve all seen the pictures of birds stomachs filled with plastic detritus and read about the Great Pacific Gyre, but I just read a new twist to that story:    the Emirates News Agency reported that decomposed remains of camels in the desert region of the United Arab Emirates revealed that 50% of the camels died from swallowing and choking on plastic bags.  “Rocks of calcified plastic weighing up to 60 kilograms are found in camel stomachs every day,” said Dr. Ulrich Wernery, Scientific Director, Central Veterinary Research Laboratory in Dubai, whose clinic conducts hundreds of post-mortems on camels, gazelles, sheep and cows in the UAE.  He adds that one in two camels die from plastic.[2]

Plastic has become so ubiquitous, in fact, that plastics are among the debris orbiting our planet. Unfortunately, our wildlife and domestic animals are paying the price now; I think we ourselves will see changes in future generations.

It’s no wonder we’re scrambling to find alternatives to plastic, and one hot topic in the research area is that of bioplastics.

Bioplastics are made (usually) from plant materials.  Enzymes are used to break starch in the plant into glucose, which is fermented and made into lactic acid.  This lactic acid is polymerized and converted into a plastic called polylactic acid (PLA), which can be used in the manufacture of products  ( PLA is about 20% more expensive than petroleum-based plastic)  or into a plastic  called polyhydroxyalkanoate, or PHA (PHA biodegrades more easily but is more than double the price of regular plastic).

The bioplastic market is expanding rapidly and by 2030, according to some estimates, could account for 10% of the total plastics market.   In the world of fabrics and furnishings, the new biotech products which are being heavily promoted are Ingeo and Sorona, both PLA based fibers with a growing share of the fabric market; and soy-based foam for upholstery.    Toray Industries has announced that they will have the first functional performance nylon and polyester textiles based on biomass ready for the 2013/14 season.  They are 100% bio-based fabrics [3] based on the castor plant, which is very robust, growing in dry farming areas and requiring significantly fewer pesticides and herbicides than other crops.

So it’s no wonder that there has been much discussion about bioplastics, and about whether there are ecological advantages to using biomass instead of oil.

The arguments in favor of bioplastics are:

  • They are good for the environment because there is no harm done to the earth when recovering fossil fuels. Also, in this process there are very few greenhouse gas and harmful carbon emissions. Regular plastics need oil for their manufacturing, which pollutes the environment.
  • They require less energy to produce than petroleum-based plastics.
  • They are recyclable.
  • They are non toxic.
  • They reduce dependence on foreign oil.
  • They are made from renewable resources.

These arguments sound pretty good – until you begin to dig  and find out that once again, nothing is ever as simple as it seems.

Regarding the first two arguments (they are good for the environment because they produce significantly fewer CO2 emissions and less energy) –  there have not been many studies which support  this argument until recently.  Recently,  several  studies have been published which seems to support that  this is indeed the case:

  1. Ramani Narayan of Michigan State University found that “the results for the use of fossil energy resources and GHG emissions are more favorable for most bio based polymers than for oil based. As an exception, landfilling of biodegradable polymers can result in methane emissions (unless landfill gas is captured) which may make the system unattractive in terms of reducing greenhouse gas emissions.”[4]
  2. University of Pittsburgh researchers did an LCA on the environmental impacts of both petroleum and bio derived plastics, assessing them using metrics which included  economy, mass from renewable sources, biodegradability, percent recycled, distance of furthest feedstock, price, life cycle health hazards and life cycle energy use. They found that  biopolymers are the more eco-friendly material in terms of energy use and emissions created.  However, they also concluded that traditional plastics can actually be less environmentally taxing to produce when taking into account such things as acidification, carcinogens, ecotoxicity, eutrophication, global warming, smog, fossil fuel depletion, and ozone depletion.[5]
  3. A study done by the nova-Institut GmbH on behalf of Proganic GmbH & Co.[6]showed unambiguously positive eco advantages (in terms of energy use and CO2 emissions) for bio based polymers PLA and PHA/PHB over petrochemical based plastics.  According to the report, “the emission of greenhouse gases and also the use of fossil raw materials are definitely diminished. Therefore the substitution of petrochemical plastics with bio-based plastics yields positive impacts in the categories of climate change and depletion of fossil resources.”  The results include:
    1. Greenhouse gas emissions of bio-based plastics amount to less than 3 KG of CO2 equivalents per KG of plastic, less than that of petrochemical based plastics which produce an average of 6 KG of CO2 equivalents per KG of plastic..
    2. the production of bio-based polymers, in comparison to all petrochemical plastics examined, leads to savings in fossil resources. The biggest savings potential can be found in comparison with polycarbonate (PC). The average savings potential in the production of PLA amounts to 56 ± 13 megajoules per kilogram of plastics here.
    3. The production of bio-based polymers in comparison with the production of petrochemical plastics in most cases also leads to greenhouse gas emission savings. The biggest greenhouse gas emission savings can be found again when comparing bio-based polymers to polycarbonate (PC). For PLA, the average savings potential in this case amounts to 4.7 ± 1.5 kilograms of CO2 equivalents per kilogram of plastics. For PHA, the average savings potential in this case amounts to 5.8 ± 2.7 kilograms of CO2 equivalents per kilogram of plastics. In comparison with PET and Polystyrene (PS), considerable savings potentials ranging between 2.5 and 4.2 kilograms of CO2 equivalents per kilogram of plastics are to be found in the production of bio-based polymers. The lowest savings potential are to be found when comparing bio-based polymers with polypropylene (PP).

So I will accept the arguments that biobased plastics produce fewer  greenhouse gases and harmful carbon emissions and require less energy to produce than petroleum-based plastics .  They also certainly reduce our dependence on foreign oil.

But are they better for the environment?  Are they recyclable or biodegradeable?  Are they safe?  Are plastics producers aware of the impact of promoting bioplastics as a replacement for plastics? We think that  bioplastics are useful for certain purposes, such as medical sutures or strewing foil for mulching in agriculture – but as a replacement for all plastics?

Next week we’ll take a look at the arguments against bioplastics.


[1] Laylin, Tafline, “Half of UAE’s Falaj Mualla Camels Choked on Plastic Bags”, Green Prophet blog, June 11, 2010.

http://www.greenprophet.com/2010/06/camels-choke-on-plastic/

[2] Ibid.

[4] Narayan, Ramani, “Review and Analysis of Bio-based Product LCA’s”, Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing, MI 48824

[5] Tabone, Michaelangelo D., et al; “Sustainability Metrics: Life Cycle Assessment and Green Design in Polymers”, Enviornmental Science and Technology, September 2, 2010.

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Renewable?

23 11 2010

We keep seeing the term “renewable”  in the media   –   a lot  –  and especially with reference to products made from “renewable resources”.  And we understand why this term can be so appealing in this time of diminishing natural resources and increasing population growth.  But what do they really mean?  Stick with us and you’ll find that this is yet another area in which a little bit of knowledge can be a dangerous thing.

A “renewable resource” is a resource that can be replenished naturally  in the same amount of time (or less) than it takes to draw the supply down.  These constantly replenishing natural resources  include forest resources,  and the fertility of agricultural land.  Some renewable resources have essentially an endless supply, such as solar energy, wind energy and geothermal pressure.   Some resources are considered renewable, even though some effort must go into procuring them, such as fisheries or food crops.

To help us make better choices, there is now a differentiation between non-renewable resources, such as petroleum or old-growth timber  (which takes centuries to renew)  and what is known as “rapidly renewable resources”.  These items, as defined by the LEED system of building certification from the U.S. Green Building Council (USGBC) offers points for rapidly renewable materials that regenerate in 10 years or less, such as bamboo, wool, and straw. To qualify for the credit in a new construction project, the value of these materials must represent at least 2.5 % of the total cost of the products used in the building.

Renewable resources have become a focal point of the environmental movement, both politically and economically. Energy obtained from renewable resources puts much less strain on our limited supply of fossil fuels (non-renewable resources). The problem with using renewable resources on a large scale, however, is that it  may create some new and unforeseen problems.

What can some of these new and unforeseen problems be?  Like all green claims, it’s terribly important to understand the wider implications of each of our choices.  Take bamboo, for example.  Bamboo is a fast growing grass which is hard enough to be used as a replacement for wood in applications such as flooring and furniture. However, most bamboo is grown and processed in China, so while ocean shipping consumes less fuel per mile than overland trucking, the type of fuel used in shipping can be more polluting. In addition, there are concerns about forestry practices, the toxicity of binders, and worker safety.  A few bamboo plantations have earned certification from the Forest Stewardship Council (FSC), which accredits forests managed “to meet the social, economic, ecological, cultural, and spiritual needs of present and future generations.” However, certified bamboo products are still not widely available in the U.S. And even though bamboo plantations sequester as much carbon as native forests, they do not support the same wildlife.  Clearly, the environmental balance is more difficult to calculate than by simply examining the length of a harvest cycle.

Another product worth examining is cork, which comes from the bark of cork oaks. Unlike nearly every other tree species, cork trees are  not harmed by removal of their bark. A mature tree is stripped about once every 10 years and lives for an average of 16 strippings. After stripping, the large slabs of bark are boiled, and bottle stoppers are punched from them. The leftover material is then ground up, pressed into sheets, and cut into tiles for flooring. This dual-purpose production is critical to the cork industry.   According to the World Wildlife Fund International, cork production provides a vital source of income for thousands of people and supports one of the world’s highest levels of biodiversity among forest habitats, with plant diversity reaching as high as 135 species per square meter. In an ironic twist, the increased market share for alternative wine stoppers could reduce the value of cork oak, leading the areas in which cork is grown to be converted or abandoned. It also may contribute to the end of the cork ecosystem.

The World Wildlife Fund International and the Forest Stewardship Council have established programs to promote and encourage responsible cork use to save this natural resource. For more information, visit www.panda.org and www.fsc.org.

Another not so easy call, is it?

In my opinion, another area worth investigating is the very visible promotion of biobased products using corn and soybeans  (soy based foam in upholstery and biobased polymers are two products that come immediately to mind) as being environmentally preferable because they’re based on a renewable resource.  Dow Cargill, manufacturer of BiOH polyols, the soybean derived biopolymer, says that it creates products with from 5 to 20% renewable content (meaning the soybeans). But soybeans are one of the three crops globally which have the highest percentage of GMO (corn and cotton being the other two).   The GMO percentage of global soybean production was 77%  in 2009, and for cotton it was 49%.  (In India, 87% of all cotton was GMO in 2009.)

Monsanto, the largest seed producer in the world, with a massive 20% share of the world market, has been  interested in a technology which was named “Terminator” – and began applying it to their seeds.

The Terminator idea was to genetically modify seeds so that the plants they produced when they grew were sterile. In biotechnology jargon, this is known as a “genetic use restriction technology”, or GURT.  Companies such as Monsanto were keen on such “suicide seeds” because they would enable the company to control any proprietary genetic traits they had engineered into the seeds. So resistance to a particular herbicide, for example, or an ability to grow faster, would not be passed on from one generation of plants to the next.

So most GMO seeds have a genetic modification that prevents the crops from setting fertile seed.  So seeds for next year’s crop must be purchased – effectively ending the centuries old practice of collecting seeds at each harvest  so they could be replanted next year.

The main problem with this is that over 1.4 billion people around the world depend on saved seeds from season to season to grow crops. Terminator seeds force dependence on the Monsantos of the world, destroying local and indigenous seed exchange practices, as well as the breeding and selection done by farmers.

There was a great outcry against this technology.

“While seeds with the ability to reproduce contain the essence of life, Terminator represents only ‘exploitation and death,’” according to Terry Boehm, vice-president of the National Farmer’s Union in Saskatchewan, Canada. Boehm further uses nuclear weapons as a parallel to Terminator technology: “Extensive testing of nuclear weapons did not change the fact that this was such a dangerous technology that it should not be used.”

At the  United Nations’ Convention on Biodiversity in Nagoya, Japan (18-29 October 2010) the Action Group on Erosion, Technology and Concentration (ETC) warned that there are a  handful of multinational corporations which are pressuring governments to allow what could become the broadest and most dangerous patent claims in history.

“The Gene Giants are stockpiling patents that threaten to put a choke-hold on the world’s biomass and our future food supply,” warns Silvia Ribeiro of ETC Group. “The breadth of many patent claims on climate ready crop genes is staggering. In many cases, a single patent or patent application claims ownership of engineered gene sequences that could be deployed in virtually all major crops – as well as the processed food and feed products derived from them,” explains Ribeiro.

Hope Shand, research director of ETC,  links the argument over Terminator technologies with wider criticisms of the ways in which agribusiness is exercising its increasingly powerful influence. “The top 10 seed companies control 57% of the commercial seed market worldwide. That’s a staggering level of corporate control over the first link in the food chain,” she says.

“Whoever controls our seeds, controls the food supply. These companies are trying to reduce competition and maximize profits by promoting laws and technologies that eliminate the practice of farmer-saved seeds. Whether it’s promoting genetic seed sterilization and patent laws, or dictating trade regimes, these trends threaten traditional farming communities and erode crop diversity.”

The ETC web site goes on to say that “the natural genetic diversity of crops is a vital insurance against future farming catastrophes. The world needs to retain as many different varieties of potato, tomato, rice and wheat as possible in case the commercial varieties grown in bulk get diseased, or are rendered useless by the accelerating impacts of global warming. That’s why there are some 1,400 “seed banks” around the world, storing some six million different species.”  For more information on this issue, see the ETC Group’s report, Gene Giants Stockpile Patents on “Climate-Ready” Crops in Bid to Become Biomassters”

I think the use of GMO crops to produce soy based foam and biobased polymers cannot be marketed as being made from a renewable resource because of the presence of these patented GMO crops – which are largely sterile. They cannot be renewed without human input – in other words, new crops cannot be grown unless the farmer purchases new seed from the corporation.  And the danger is that these genetic mutations will spread to non GMO crops.

This goes entirely against the intent  in defining a renewable resource.  These crops cannot be “created again”.  So to say that soy based polyols (or soy based foam) is made from a “renewable resource” is false.

Another objection I have to GMOs as they are being implemented is that the basic motivation for almost every introduction thus far is profit-driven rather than need-driven – but that’s nit picking.

For more information on Terminator Technology visit:

www.banterminator.org – the Ban Terminator Campaign

www.etcgroup.org – Action Group on Erosion, Technology, and Concentration

• Also see www.seedsofchangefilm.org for information on the film, “Seeds of Change,” which looks at genetically modified crops and how they are changing the face of agriculture in western Canada. This film was made back in 2002 but hidden from the public by the administration at the University of Manitoba until 2005. Click here for a review of this documentary.