Life cycle assessment of petrochemical products : polystyrene and polyurethane foam

Abstract

In this research, a life cycle assessment (LCA) study was conducted to assess the environmental impacts of the production of two commercially important petrochemical products, polystyrene (PS) and polyurethane foam (PU foam). Life cycle inventory (LCI) data for both PS and PU were collected from DOW Chemical Company plants in Maptaphut, Rayong. LCA software, SimaPro 5.1 with Eco-Indicator 95 and Eco-Indictor 99 methods, was used to assess the environmental impacts. The system boundary of PS and PU foam production was set to include manufacturing, distribution and transportation of raw materials and products, use phase (injection) at the plastic manufacturing companies and disposal (landfill, incineration and recycle). For PS, two products were studied separately; general purpose PS (GPPS) and high impact PS (HIPS). The results showed that the environmental impacts of these two model petrochemical products (PS and PU) come mainly from the manufacturing and use phases. For PS, the environmental impacts were found to be essentially from styrene monomer (both GPPS and HIPS) and polybutadiene rubber (only HIPS) in the manufacturing phase and the generation of electricity used in the use phase which resulted in depletion of fossil fuels, acidification and summer smog. For PU, the impacts caused mainly by two important raw materials, isocyanate (MDI) and polyether-polyol, which resulted in resources depletion, heavy metal effect and acidification. It was also observed that the production of PS creates the environmental impacts approximately 1.5 times higher than PU foam.