DOI: http://dx.doi.org/10.1065/lca2002.02.076
--- The goal of this study was to calculate the average
CO2 emissions for manufacturing three commodity plastics,
polyethylene (PE), polypropylene (PP), and polyvinyl chloride
(PVC) in Japan. The CO2 emissions were calculated from cradle
to gate, excluding the calcination processes after use. As the
results, the followings were observed:
1) The gross CO2 emissions for the manufacture of plastics in
Japan were 1.3, 1.4, and 1.7 kg-CO2/kg-PE, PP, and PVC, respectively.
These mainly reflected the difference of CO2 emissions
for the in-house electricity generation. 2) The CO2 emissions
for the electricity used for manufacturing PVC were higher
than that used for PE and PP, because additional electricity was
required for the electrolysis to produce chlorine. The gross electricity
consumption for manufacturing PVC was 1.3 kWh/kg-
PVC, and the other plastics consumed 0.5 kWh/kg-Products.
In addition, the effects of energy saving were studied using a
projected gas-diffusion electrode for the electrolysis of salt on
the reduction of CO2 emissions. It was estimated that the reduction
in CO2 emissions was 7% compared with the present PVC
manufacturing processes. |
