Materials & Processes


chemistry department at the university, is investigating how it might make starch-based plastics from the egg shells. Food producers need to pay to dispose of egg shells in


landfill: Leicester-based Just Egg, for example, uses 1.3 million eggs per week, and spends £30,000 a year to send 480 tonnes of shells to landfill. The company’s managing director, Pankaj Pancholi, said:


“It would be great if the egg shells could be recycled into the plastic packaging that we use for egg products.” The project aims to develop a way to convert the egg shells


into a range of starch-based plastics, and test the mechanical properties such as strength. The researchers also intend to identify ways to use the egg shells as fillers that could ‘bulk up’ different grades of plastic. Potential applications include


ready meal


food trays and shop fittings - though


the ultimate goal is to produce


Fig. 2. The BioIsoprene tyre, which is derived from sugar, should be a commercial reality in 2013.


packaging that protects egg products. The team


will also try to extract proteins


called glycosaminoglycans (GAGs), for possible use by the pharmaceutical industry.


Waste lines


Plant waste materials is another potentially fertile source that could be used to make bioplastics. The Oil Palm Biomass Consortium (OPBC), coordinated


by Netherlands-based TU Delft, and the innovation unit of the Malaysian Prime Minister’s office, will look at the use of palm waste as a raw material for the chemical industry. Malaysia is one of the world’s largest exporters of palm oil, but current production processes use only the palm fruit. “The waste of the palm plant, such as the stem, leaves


and the processed palm fruits, can form an important source of biomass for bio-fuels, bio-plastics and other products,” said Luuk van der Wielen, professor of bioseparation technology at TU Delft. “The use of such organic materials as palm waste is becoming much more attractive as a more sustainable source of raw materials for the production of chemicals. By this collaboration Dutch chemical companies can gain access to this resource as well.” But these natural materials are not always used as


chemical precursors. In some cases, they can be used as ‘fibre providers’, adding reinforcement to conventional polymers. An example is Curran, a cellulose material extracted from carrot waste by Scottish company Cellucomp. It can


be blended with a range of conventional resins – including polyurethane, polyester and epoxy – to create composites with high stiffness, strength and toughness. Cellucomp is working with Dutch farm cooperative Royal


Cosun to commercialise the material. Curran, combined with carbon fibres, was used to make the Reactor fishing rod, while sheets of the material have been used to produce a skateboard. The material is currently made in a pilot plant, but is


expected to be commercially available next year. Biowert of Germany is using grass from local farmers to


create a range of products, including a bioplastic. AgriPlast granules comprise 40-75 per cent cellulose fibres


from meadow grass (which is produced during the process of crop rotation) and 25-60 per cent recycled polypropylene (PP) or polyethylene (PE). It says that parts made from its AgriPlastic are around 20 per cent lighter than those made from PP or PE. The granules are free-flowing and can be injection


moulded into components such as spoons, brackets, machine cases, and protective caps. Biowert says the material has high flow, which ensures fast cycle times during production.


Flexible production


The automotive industry is also looking for new sources of material. It is the leading consumer of rubber – so the leading tyre manufacturers are actively seeking alternative sources of the material. Continental is pinning its hopes on dandelions – due to


a fungal infection that is threatening rubber trees worldwide. Researchers at the University of Münster and the Fraunhofer Institute for Molecular Biology and Applied Ecology (IME) have identified an enzyme that controls polymerisation of the plant’s latex. By switching off the enzyme, the latex can flow freely – and be used industrially. Dirk Prüfer, of the Institute for Institute of Plant Biology


and Biotechnology at the university, says: “The first results show that Russian dandelions produce a high-quality natural rubber. Its physical and chemical properties match up well with those of the Brazilian rubber tree.” The dandelions would need to be ‘farmed’ on a huge


scale, but could be established quickly in response to increased demand for rubber. At the same time, Goodyear is looking to avoid the


fluctuating price and availability of petroleum-derived isoprene through a deal with biotechnology company Genencor. The deal gives Goodyear a sustainable source of isoprene (the monomer from which synthetic rubber is made). Isoprene is traditionally sourced from crude oil, but Genencor has uses special enzymes to ‘ferment’ it from starch. It expects to begin commercial production in the US next year. Whether it is rubber, engineering plastics or commodity


resins, the search for alternative feedstocks is accelerating. But while today’s alternatives are invariably ‘food’ crops, those of the future will be waste products. Just as the ancient alchemists dreamed of turning base


metals into gold, so today’s chemicals producers are looking to use biotechnology and sophisticated catalysts to turn muck into money - or, at the very least, plants into plastic. l


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