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Team:Imperial College/Bioplastics
From 2013.igem.org
Producing and Recycling Bioplastics
We are producing the bioplastic poly-3-hydroxybutyrate(PHB) using the organic material in the waste product, solid recovered fuel. We have also devised the first method for recycling PHB and are working with Yale to do the same for PLA. Here you will find out why.
Bioplastics have a bright future
Bioplastics are made either directly by living things or from the products they make. They are usually more environmentally friendly than petrochemically derived plastics(1) and do not rely upon finite fossil fuels. Advances in how they are produced is allowing bioplastics with controllable physical properties to be produced(3) which enables uses which mimic those of oil-based plastics. The properties of some bioplastics allow novel functions to be carried out; an exciting example of this is the production of biocompatible scaffolds which can be used in surgical treatments(4). This combination of innovations leading to improved functions and the development of novel uses combined with environmental benefits over petrochemical plastics are just some of the reasons why bioplastics are expected to flourish commercially in the coming years(5). Currently around 10% of the plastics market consists of bioplastics, with this predicted to increase to around 30% by 2020. This is a huge increase and represents significant commercial opportunities. The predicted production of such a large amount of material requires careful consideration of what we do once we have used the products produced, called end of life solutions.
Poly-3-Hydroxybutyrate and Polylactic Acid are two of the best developed bioplastics
Poly-3-hydroxybutyrate(P3HB) and Polylactic Acid(PLA) are both commonly used and well studied bioplastics. Currently several different companies produce each by a variety of methods(9).
Poly-3-Hydroxybutyrate<b>
P3HB is produced as an energy store in some bacteria. Commercially it is produced in bioreactors from sucrose and other sugars derived from plant biomass. P3HB can also be produced in the stems of plants, however this requires large inputs of fertiliser and large areas of land. Interest in the production from the fermentation of organic waste materials is also increasing. P3HBs are being investigated for uses in many things from food packaging to discount cards to replacements for current plastics made from polymer blends.
<b>Polylactic acid
Polylactic acid production is usually a chemical process, building up the monomers of lactic acid or lactide. It can also be produced by certain organisms. Biological systems of PLA production are also possible. This is what our collaborators at Yale are working on. PLA already sees use in the packaging industry and plastic bottles. Future uses as with many ‘biodegradable’ plastics will expand to include tasks where increased durability are needed(8).
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Our Solution
<p>Our system is designed to recover the valuable resources locked up in the SRF, transforming it from a waste material into the commodities ethylene glycol and poly-3-hydroxybutyrate; a feedstock for many applications and a useful bioplastic respectively.
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