The greenhouse gas (GHG) emissions assessment for the product life cycle was conducted within a Business–to–Customer (B2C) system boundary, covering all stages from raw material acquisition to end–of–life disposal. The study focused on a pyrolysis reactor and pyrolysis oil, with the functional unit defined as one pyrolysis reactor (302 kg) and 1 kg of pyrolysis oil. Total GHG emissions over the reactor’s life cycle reached 3,100.72 kgCO2e, with the usage phase, assuming six years of operation, accounting for the majority at 2,973.24 kgCO2e, mainly due to Liquefied Petroleum Gas (LPG) combustion as the primary fuel. Emissions from raw material acquisition amounted to 125.55 kgCO2e, while the manufacturing phase contributed a minimal 1.10 kgCO2e, primarily from electricity used in component assembly. The life cycle GHG emissions for pyrolysis oil totaled 6.08 kgCO2e. The highest GHG emissions occurred during the usage phase, where pyrolysis oil replaced fuel oil in stationary combustion, contributing 56.13% of total emissions with 3.42 kgCO2e. The second-largest source was raw material preparation, involving compression of polypropylene (PP) waste into densified form, which emitted 33.43% or 2.03 kgCO2e, mainly due to electricity use. The pyrolysis process accounted for 10.44% or 0.63 kgCO2e, primarily from LPG combustion. A small amount of CO2 was also emitted from burning non-condensable combustible gases, which served as supplementary fuel in the process.
Saramath et al. (Wed,) studied this question.