Comparative LCA study of conventional plastics from sugarcane and crude oil

Övrigt konferensbidrag, 2010

The increasing industrial interest in renewable materials has lead to the development of new plastics via biological routes. However, due to differing material properties their integration into existing plastics applications is constricted. This constriction has initiated a rethinking of the production of conventional plastics such as polyolefins (PE and PP) and launched the application of biomass as their raw material. Although both developments are based on the use of renewables the question arises to what extent and what respect ‘renewable’ also means ‘environmentally preferable’. This needs to be considered for material and process developments. The goal of our study is to answer ‘if renewable is environmentally preferable’ for the production of polyethylene (PE) and to identity and quantify its environmental impact. Two different process routes were therefore assessed and compared. • conventional crude oil based route, which for our case is located in Northern Europe • PE production on the basis of sugarcane, which is cultivated and processed in Brazil (not yet established) The two approaches for Life cycle assessment (LCA) – consequential and attributional – were used to assess the environmental performance of these two routes. As the crude oil process is already established, data from producers are available, and were used for this part of the LCA. In contrast, the cane route is only industrialized up to the production of ethanol. Therefore, data for the dehydration of ethanol to ethylene (base material for PE) were estimated using the process simulation software Aspen HYSYS. Preliminary results indicate the importance of land use change (LUC) on the potential environmental impact of the cane based PE and point out the large effect of modeling approaches on the outcome of the LCA.