Life cycle inventory analysis of CO2 emission from the manufacturing of polyvinyl chloride resins

Plastics are indispensable materials for life cycle assessment (LCA), becau se they are as important basic raw materials as steel with its variety of a pplications including automobile and electric/electronic equipment. The LCA is also useful for evaluating the validity of recycling of plastics. In th is paper, the amount of CO2 emission from the production of Polyvinyl chlor ide resins (PVC) was calculated by using the LCA methodology. The energy st ructure such as in-house electric power generation in the industries associ ated with the production of PVC was analyzed. The analysis of life cycle in ventory (LCI) has been conducted under various scenarios based on the tradi ng extent of the processes related to PVC production, and as a result, the followings have been observed. (1) The gross CO2 emission from the producti on of PVC varied in the range of 1.5-2.0 kg-CO2/kg-PVC, reflecting the diff erence in the unit value of CO2 emission attributable to in-house electric power generation in each of the industries related to PVC production. (2) T he gross electricity consumption of PVC production was as high as 1.30 kWh/ kg-PVC, and the CO2 emission attributable to the power generation was 63-72 % of the total CO2 emission, while chlorine production consumed 0.73 kWh/kg -PVC. (3) It was necessary to evaluate the average amount of CO2 emission f rom the production of PVC in Japan based on the energy structure of the ind ustries related to PVC production. Moreover, the amount of CO2 emission is greatly influenced by the allocation methodology for electrolysis of NaCl. Also, the effect of reduction on the CO2 emission of the projected gas diff usion electrode for energy saving was discussed by means of quantitative LC I analysis.