Evaluation of Plastics Manufacturing in Terms of Energy Consumption and CO₂ Emissions

Abstract

Energy consumption and carbon dioxide (CO₂) emissions for manufacturing plastics in Japan were evaluated in order to determine the potential for energy savings and reductions in CO₂ emissions. Energy consumption for manufacturing plastics comprised 42% of the total consumption for all chemical industries in Japan. However, 54% of the energy is retained in the plastic products themselves. The retained energy of 37.0 GJ/t corresponds to 2.6 times the energy consumption (15.2 GJ/t) in a crude steel production process with an integrated steel plant. Recycling of waste plastics is therefore essential for energy conservation. The CO₂ emissions from plastics manufacturing was 37% of the total for the whole chemical industry, a quantity smaller than those from steel, cement-ceramics, or petroleum industries. Replacement of some types of plastics by more environmentally friendly ones and recycling of waste plastics were also discussed from the standpoints of both energy and CO₂ emissions.