June 9, 2006

Bioresin and bioplastics are two new words to add to your spell checker. They refer to polymer plastics that are made from biomass organic materials instead of traditional petroleum feedstock. The one in commercial use is mostly corn, although development work is underway with stover, switch grass, wheat straw, and rice straw, among others. The high price of crude oil has given impetus to the industry.

Metabolix and ADM (Archer Daniels Midland) are Vincent customers making the most news. They have recently announced they will build a 100 million pounds per year (mpy) plant in Clinton, Iowa. Metabolix, a 1992 spin-off by MIT, acquired technology from Monsanto in 2001 for the production of organic PHA, polyhydroxyalkanoate.

PHA is produced by fermenting corn sugar with genetically modified bacteria. The resulting mash is separated in Vincent screw presses, after which the resulting polymer resin is dried in a steam tube dryer.

A key characteristic of bioplastics is that, unlike petroleum based plastics, they biodegrade in a few months. This occurs either in soil or sea water. At the same time, bioplastic products have an indefinite shelf life.

PHA is a thermoplastic that serves as a substitute for PET (2-liter Coke bottles) and polystyrene. It can also replace polyethylene and polypropylene. The initial product to be produced by ADM is agricultural stakes. Plastic cutlery, coated paper cups, bottle caps, drinking straws, cosmetic cases and foam coffee cups will follow.

An alternate, better established bioresin is corn-based PLA, polylactide. This has been produced in Blair, Nebraska since 2002 by NatureWorks. Starting as a 1992 joint venture, NatureWorks had an ownership change in January 2006, when Cargill bought out their partner, Dow Chemical. The Blair plant has a capacity of 300 mpy. This bioplastic is used to make containers and packaging for produce, pineapples, melons, drinking cups, and deli containers. Newman's Own salad dressing containers and Biota drinking water bottles are made from PLA.

Foreign firms are also producing bioplastics. BASF in Germany calls their Ecovio, and they produce 13 mpy, targeting the carrier bag and packaging film markets. Novamont in Italy has production capacity of 80 mpy of polyester-based bioresin, serving bioplastic film markets. Grenidea Technologies in Singapore has been producing their Agroresin from palm oil biomass since 2003, for bakery trays and fresh produce containers. In Japan, Mitsui Chemicals produces their Lacea PLA for packaging electronics, envelope windows, prepaid phone cards, and industrial strapping. Worldwide production capacity is currently estimated to be 800 mpy.

Issue 174