Tham khảo tài liệu 'volume 20 - materials selection and design part 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Table 1 Percentage of emissions generated during each stage of the vehicle life cycle for a steel unibody and an average aluminum design Emission type Emissions produced Mining refining Production Use Post-use Steel unibody CO2 0 HC 0 0 NO 0 CO 0 0 Particulate -- SO 0 Aluminum body CO2 0 HC 0 0 NO 0 CO 0 0 Particulate 0 SO 0 Results show that the aluminum designs perform better in the pollutant categories that dominate during the use phase CO2 hydrocarbons NO and CO . However for particulates and sulfur oxides the steel design is more competitive. Emissions associated with the aluminum design are greater for the mining and refining stage sulfur oxides and particulates . For the categories that arise predominantly during vehicle use CO2 hydrocarbons NO and CO the lightweighting achieved in the aluminum designs pays off. Analysis of the inventory data does not lead to an unambiguous result. On a cost basis even with a life cycle approach the steel unibody is most competitive. However if the goal is to reduce greenhouse gases and smog precursors one of the aluminum designs may be preferred Fig. 13 . Emission Type Change when using aluminum CO2 HC NO CO Particulate 438 SOX 264 Fig. 13 Emissions throughout the entire product life cycle for steel and aluminum automobile bodies Impact and Evaluation. Most efforts to develop the LCA technique have focused on constructing a complete set of procedures for the collection and organization of the information that must be developed in the course of a LCA. However determining what to do with this information once it is collected has so far been only imperfectly addressed. Although the reason for employing LCA is to develop activities that reduce environmental impact establishing how this mass of data informs specific problems has .
