Note: This is the first article of a three-part series covering bioplastics (1) trends, (2)material/process advances and (3) applications.
By way of an introduction definition, the term bioplastics is not limited to biodegradable or compostable plastics made from natural materials such as corn or starch. Bioplastics is also applied to petroleum-based plastics that are degradable; natural-based plastics that are not necessarily biodegradable; and plastics that contain both petroleum-based and plant-based materials that may biodegrade or not.
Bioplastics are distinguished in two categories: bio-based and/or biodegradable.
- Bio-based plastics: The major focus of this material is the "origin of its carbon building blocks," and not by where it goes at the end of product life.
- Biodegradable plastics: The focus here is on a materials "end of life disposal" independent of its carbon source.
Bio-based material is not necessarily biodegradable nor is biodegradable material necessarily bio-based. Ethylene from ethanol is identical to ethylene from naphtha, and plastics made from bio-ethylene are indistinguishable from petrol-derived resins. Also, some petrochemical-based polymers are biodegradable. One example is Ecoflex, a BASF product that readily biodegrades in commercial compost systems.
Plastics Institute of America
Bio-based raw material source (left), and bioplastics can be bio-based, biodegradable or both (right).
Bio-based content refers to the weight fraction of the total organic carbon in the material that is bio-based. Originally developed for bio-based content determination of products for the U.S. Department of Agriculture (USDA) BioPreferred Program, American Society for Testing and Materials (ASTM) D6866 is a standardized analytical method for determining bio-based content of materials using radiocarbon dating and is widely used in the bioplastics industry.
- ASTM D6866 bio-based content computation only considers total organic carbon content, not product weight.
- The standard does not measure product biodegradability.
Biodegradable products refer to any organic substances capable of being broken down by microorganisms independent of carbon source. Recently, the European Bioplastics Association estimated that of 1.16 million metric tons (mt) global bioplastics capacity in 2011, 58 percent were bio-based/nonbiodegradable. The group predicts bio-based/nonbiodegradable plastics will grow to 87 percent of the estimated 5.8 million mt global bioplastics capacity that will exist by 2016.
Petrochemical-based materials make up the majority of plastics — approximately 280 million tons of plastics produced worldwide. Global bioplastics production capacity will see almost a fivefold increase from 2012 to 2016. Growing from around 1.2 million tons in 2012, the production capacity for bioplastics will increase to a predicted 5.8 million tons by 2016.
By far the strongest growth will be in the bio-based nonbiodegradable plastics group. The composition of bioplastics production capacity is expected to change significantly from 58 percent bio-based/nonbiodegradable in 2012 to 87 percent by 2016.
Drop-in bioplastics — chemically identical to petroleum-derived plastics — are rapidly gaining acceptance at much greater speed compared to other bio-based plastics. Use of these drop-in materials involve much less risk versus unknown novel materials and are compatible with existing recycling streams.
Leading the field is partially-bio-based PET (polyethylene terephthalate), which accounts for approximately 40 percent of the global bioplastics production capacity. This bioplastic is expected to see a 10-fold increase to 80 percent of total bioplastics production capacity in 2016 to 4.5 million tons.
Following PET is bio-based PE (polyethylene), another drop-in material strongly driving bioplastics growth with 250,000 tons, or more than 4 percent of the bio-based production capacity predicted for 2016.
Other drop-ins that have been or are being commercialized include bio-based nylon, polypropylene, polystyrene, polycarbonate, PVC (polyvinyl chloride) and many other traditional plastics. While Europe is the world's largest market for bioplastics, production capacity is growing most rapidly in Asia and South America.
The bioplastics market has been growing roughly 20 percent per year with a mix of industry internal and external market drivers facilitating this growth. For industry players, the advantages focus on advanced technical properties, which increase product attractiveness, potential cost reduction through economies of scale, and the development of additional disposal options.
Industry external drivers include high consumer acceptance, the looming danger posed by climate change, the increasing price of fossil materials, and our current dependence on fossil resources. Increasing public concern about the environment, climate change and long-term limited global fossil fuel resources are important drivers for governments, companies and researchers to find alternatives to petroleum-based plastic materials.
Interest in bio-based plastics is closely connected to the price of oil, and is a key driver for demand of bio-based polymers when oil exceeds $80 per barrel. According to bioplastics experts, if oil prices stabilize around $90 per barrel, then most bioplastics technologies have the potential to compete with petroleum-based plastics. Brent crude, used to price international varieties of oil, closed recently above $104 per barrel on the London market.
The shale gas boom has added a new dimension to the investment case for bioplastics. Shale gas offers an inexpensive and abundant ethylene feedstock source. Both PET and PE are ethylene-based plastics, and the new cost-advantaged ethylene from shale gas is adversely impacting these bio-ethylene derived plastics markets by increasing the premium on bio-ethylene. For example, Dow and Mitsui in the last year have announced that they were postponing phase two of their bio-ethylene project while they review market conditions and project economics.
The shale gas revolution is also significantly changing the picture for other oil-based plastic feedstocks. The use of shale gas to make ethylene has meant a switch away from naphtha, from which plastic feedstocks such as propylene, butadiene and benzene are derived. This may lead to an ongoing shortage of these higher carbon chemicals and be supportive of related renewable feedstock economics.
Government legislation and incentives are also strong drivers. The Japanese government has set a goal that 20 percent of plastics consumed in Japan will be renewably sourced by 2020. In 2012, U.S. President Barack Obama signed a presidential memo that requires the federal government to track and increase its purchases of products made from plants and other renewable agricultural materials.
Companies that meet compostability standard EN (European Norm) 13432 can expect to experience larger growth due to granting of application decree for banning PE bags in Italy. The Decree is enforcing large and costly sanctions from 2,500 to 25,000 euros per infraction for companies that do not follow the legal requirements.
Some companies have mandated increased use of renewably sourced materials in their products for marketing differentiation, reduced environmental footprint or weight reduction such as in automotive. Toyota has set the goal of using renewable or recycled material in 20 percent of its plastic resin parts by 2015.
