Jefter Fernandes Nascimento

Sustainable Embedding of the Bioplastic Poly-(3-Hydroxybutyrate) into the Sugarcane Industry: Principles of a Future-Oriented Technology in Brazil

To make the biodegradable polymer poly-(3-hydroxybutyrate) (PHB) economically competitive with common end-of-pipe plastic materials from petrochemistry, the production costs have to be reduced considerably. The embedding of the industrial PHB production into a sugar and ethanol factory starting from the raw material sugarcane makes it possible to achieve a production price per kilogram PHB that is 4–5 times lower than known for prior PHB production processes. This cost reduction is enabled by an extensive utilisation of by-products of the sugarcane plant, especially of bagasse. In the presented process, this typical waste product is burned for generation of the steam and electrical energy required for the process. Furthermore, the availability of the substrate sucrose in high quantities leads to the gained price advantage. Together with the application of ethanol as an alternative fuel, CO2 emissions from the production plant return to the sugarcane fields via photosynthetic fixation, resulting in a carbon balance of nearly zero. The utilisation of medium chain length alcohols, by-products of the ethanol production integrated in this plant, substitutes the classic PHB extraction method using chlorinated agents. In this way, the major drawbacks regarding profitability and environmental embedding of PHB production are solved within a future-oriented, integrated process.