Life Cycle Design of a Fuel Tank System
This life cycle design (LCD) project was a collaborative effort between the National Pollution Prevention Center at the University of Michigan, General Motors (GM), and the U.S. Environmental Protection Agency (EPA). The primary objective of this project was to apply life cycle design tools to guide the improvement of fuel tank systems. Two alternative fuel tank systems used in a 1996 GM vehicle line were investigated: a multi-layer high density polyethylene (HDPE) tank system, and a steel tank system. The design analysis included a life cycle inventory (LCI) analysis, performance analysis and preliminary life cycle cost analysis. The scope of the LCI study encompassed materials production, the manufacturing processes for each tank system, the contribution of each tank system to the use phase burdens of the vehicle, and the end-of-life management processes based on the current vehicle retirement infrastructure.
The LCI analysis indicated lower energy burdens for the HDPE tank system and comparable solid waste burdens for both systems. Based on the results of the LCI, streamlined environmental metrics were proposed. While both systems meet basic performance requirements, the HDPE system offers design flexibility in meeting capacity requirements, and also provided a fuel cost savings. The life cycle design framework was useful in evaluating environmental, performance, and cost trade-offs among and between both fuel tank systems.