The Potential of Bio-based Plastics

Li Shen, Juliane Haufe and Martin K. Patel of the Copernicus Institute for Sustainable Development and Innovation at the University of Utrecht (the Netherlands) recently published a study, titled: “Product overview and market projection of emerging bio-based plastics.”

Who really is interested to work through the 243 pages of the highly-recommended study can download the study here. For the executives, the fast-living packaging professionals and all who want to know what’s in it, I made a compilation of extracts I took from the study.

First. In this study, the term “bio-plastics” is avoided due to its ambiguity: it is sometimes used for plastics that are bio-based and sometimes for plastics that are biodegradable (including those that are made from fossil instead of renewable resources). The term used is: bio-based plastics.

Second. In this study bio-based plastics are defined as man-made or man-processed organic macromolecules derived from biological resources and for plastic and fibre applications (without paper and board). The bio-based plastics investigated in this study include starch plastic, cellulose polymers and plastics, PLA (polylactic acid), PTT (polytrimethylene terephthalate), PA (polyamides), PHA (polyhydroxyalkanoates), PE (polyethylene), PVC (polyvinylchloride), and other polyesters (e.g. PBT [polybutylene terephthalate], PBS [polybutylene succiniate], PET [polyethylene terephthalate] and PEIT [polyehthylene-coisosorbite terephthalate]), PUR (polyurethane) and thermosets (e.g. epoxy resins). For each of these plastics, the study presents the bio-based production routes, material properties, technical substitution potentials, applications today and tomorrow, emerging producers and wherever possible, costs.

Let’s start with a bit of history.
Polymers abound in nature. Wood, leaves, fruits, seeds and animal furs all contain natural polymers. Bio-based polymers have been used for food, furniture and clothing for thousands of years. The first artificial thermoplastic polymer “celluloid” was invented in the 1860s. Since then, numerous new compounds derived from renewable resources have been developed. However, many of the inventions related to bio-based polymers made in the 1930s and 1940s remained at the laboratory stage and were never used for commercial production. The main reason was the discovery of crude oil and its large scale industrial use for synthetic polymers since the 1950s.
Today, public concern about the environment, climate change and limited fossil fuel resources are important drivers for governments, companies and scientists to find alternatives to crude oil. Bio-based plastics may offer important contributions by reducing the dependence on fossil fuels and the related environmental impacts.

Packages in NatureWorks PLA

In the past two decades bio-based plastics have experienced a renaissance. Many new polymers from renewable feed stocks were developed. For example, starch, i.e. a naturally occurring polymer, was re-discovered as plastic material. Other examples are PLA that can be produced via lactic acid from fermentable sugar and PHAs which can be produced from vegetable oil next to other bio-based feed stocks.
The developments in the past five years in emerging bio-based plastics are spectacular from a technological point of view. Many old processes have been revisited, such as the chemical dehydration of ethanol which leads to ethylene, an important intermediate chemical which can be subsequently converted into polyethylene (PE), polyvinyl chloride (PVC) and other plastics. Moreover, recent technology breakthroughs substantially improved the properties of novel bio-based plastics, such as heat-resistance of PLA, enabling a much wider range of applications. For numerous types of plastics, first-of-its kind industrial plants were recently set up and the optimization of these plants is ongoing.

Wood pulp based NatureFlex of Innovia Films

The historical use of bio-based products demonstrates that bio-based polymers are neither fictional nor totally new. Instead, for many decades, they have been an industrial reality on a million-tonne-scale. Today, the combined volume of these non-food and non-plastics applications of starch and man-made cellulose fibres is 55 times larger than the total of all new bio-based polymers (approx. 20 Mt (million metric tonnes) versus approx. 0.35 Mt in 2007). The new bio-based polymers may reach this level in 20-30 years from now. The use of starch for paper production only amounts to 2.6 Mt and is hence still six times larger than today’s worldwide production of bio-based plastics. This demonstrates that the production of bio-based products at very large scale is not unprecedented.

This study estimates the global capacity of emerging bio-based plastics at 0.36 Mt by the end of 2007. This is approximately 0.3% of the worldwide production of all plastics (dominated by petrochemical plastics). The current production capacity of bio-based plastics is even smaller compared to “conventional bio-products”: they represent only 2% of the global production of established bio-polymers (20 Mt; comprising cellulose polymers, alkyd resins and non-food starch without starch for fuel ethanol) and only 0.1% of the world paper and board production. However, the market of emerging bio-based plastics has been experiencing rapid growth. From 2003 to the end of 2007, the global average annual growth rate was 38%. In Europe, the annual growth rate was as high as 48% in the same period.

Frito-Lay’s plant-based chips bags

The total maximum technical substitution potential of bio-based polymers replacing their petrochemical counterparts is estimated at 270 Mt, or 90% of the total polymers (including fibres) that were consumed in 2007 worldwide. It will not be possible to exploit this technical substitution potential in the short to medium term. The main reasons are economic barriers (especially production costs and capital availability), technical challenges in scale-up, the short-term availability of bio-based feed stocks and the need for the plastics conversion sector to adapt to the new plastics. Nevertheless, this exercise shows that, from a technical point of view, there are very large opportunities for the replacement of petrochemical by bio-based plastics.

Based on company announcements it is projected that the most important items by 2020 will be starch plastics (1.3 Mt), PLA (0.8 Mt), bio-based PE (0.6 Mt) and PHA (0.4 Mt). The BAU (business-as-usual) scenario assumes a steady growth of the four key plastics (i.e. starch plastics, PLA, bio-based PE and bio-based epoxy resin) and a modest growth for cellulose films, PHA and bio-based PUR. The BAU projection results in a global production capacity of approximately 3 Mt for 2020.

It will hence take more than two decades from now until meaningful benefits such as CO2 emission reduction will be achieved at the macro level. On the other hand, the advantages of the slow substitution of petrochemical plastics are that technological lock-in can be more easily avoided and that an optimized portfolio of processes can be implemented ensuring maximum environmental benefits at lowest possible costs and minimum social backlash.

To conclude, several factors clearly speak for bio-based plastics. These are the limited and therefore uncertain supply with fossil fuels (especially oil and gas), the related economic aspects, environmental considerations (especially savings of non-renewable energy and greenhouse gas abatement), innovation offering new opportunities (technical, employment etc.) and rejuvenation in all steps from chemical research to the final product and waste management. Challenges that need to be successfully addressed in the next years and decades are the lower material performance of some bio-based polymers, their relatively high cost for production and processing and the need to minimize agricultural land use and forests, thereby also avoiding competition with food production and adverse effects on biodiversity and other environmental impacts.

As the conclusions of the study are of utmost importance, I shall post here a second article (within a few days) with the conclusions of the study in more detail.

The study was commissioned by the European Polysaccharide Network of Excellence (EPNOE) and European Bioplastics.

In the meantime if you like to read it in full, here it is with its typical scientific title: “Product overview and market projection of emerging bio-based plastics”.


2 responses to “The Potential of Bio-based Plastics

  1. Pingback: Excellence in Packaging » Blog Archive » Cubis - ‘cubed’ Innovative Beverage Bottles·

  2. Pingback: Excellence in Packaging » Blog Archive » Bio-based Plastics From Algae - An Old is New Again Story·

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