razilian petrochemical firm Braskem S.A. (Sao Paulo) plans to have 200,000 tonnes/yr of production capacity for its sugar-cane based polyethylene (PE) online, with work on sugar-cane derived polypropylene (PP) and EPDM (ethylene propylene diene monomer) rubber ongoing. Leonora Novaes, green polymers commercial leader at Braskem, laid out her company's progress in commercializing a PE based on sugar-cane generated ethanol at TAPPI's PLACE 2010 Conference (April 18-21, Albuquerque, NM), as well as pointing out the material's greenness relative to fossil-fuel based polymers and some biobased ones.
Instead of corn or sugar beets, Braskem is utilizing sugar cane to create ethanol, which is then sent through a "dehydration" plant. As the name would suggest, that operation removes water from the ethanol, leaving ethylene in its place. Novaes said that for every one unit of fossil fuel put into the sugar-cane process, you end up with 9.3 units of energy. This compares quite favorably to the 1.4 units of energy output from corn or 2.0 units from sugar beets. In addition, Novaes described sugar cane as a "carbon capture" crop, saying its density and size, with mature plants reaching 10 feet, coupled with the fact that it will return annually for anywhere from 6-10 years without replanting, give it a net-negative carbon footprint. Novaes said that from 1 kg of fossil-fuel based PE, you get 2.5 kg of carbon dioxide, while 1 kg of Braskem's green PE actually captures 2.5 kg of carbon dioxide. Utilizing all portions of the plant, 1 hectare of land produces three tonnes of PE, with Novaes saying that the country's industrial sugar-cane production, which also supports its aggressive liquid fuels program, is not encroaching on rain forests.