Carbon Footprint Analysis of a Polymer Manufacturing Process

This paper describes a carbon footprint (CF) analysis of a
manufacturing process based on large scale polymer food tray production
using Polyethylene Terephthalate (PET). The methodology utilised, allows
for the calculation of the CF, in accordance with PAS (Publically
Available Specification) 2050, of a 16.6g recycled PET (rPET) tray, based
on a cradle-to-grave life cycle. Using an Irish plastics manufacturer as the
experimental basis for the research, primary activity data was measured for
in-house processes while secondary data was used for upstream and
downstream stages. The CF of a 16.6g rPET tray was found to be 23.42 g
CO2e or 1.4106kgCO2e.kg-1 trays. The raw material inputs and
manufacturing processes were found to contribute 45% and 33% of the
greenhouse gases emissions (GHGs),respectively. The end-of-life stage
was found to contribute 18% of the GHGs, while the secondary packaging
and transport stages contributed only 2% each. By manufacturing the tray
with 85% recycled content, the CF was found to be 60% lower compared
to a benchmark based on only virgin materialutilisation. By increasing the
end-of-life recycling rate from 22.5% to 32%, the CF was found to be
reduced by 2%. Transport was found to have a minimal effect on CF.