Carbon footprint accounting is a key tool for formulating product carbon reduction strategies. We constructed a carbon footprint accounting model for insulating oil products based on the life-cycle assessment (LCA) framework. Through case studies

the carbon emission patterns of natural ester insulating oil and mineral insulating oil were compared. The study reveals that

under combustion disposal

the total carbon emissions of natural ester insulating oil is 2 874.90 kg CO2e. Benefiting from the carbon sequestration effect of the raw material crops of natural ester insulating oil

the emissions in the raw material input stage is −1 582.69 kg CO2e

showing carbon absorption. In contrast

the total carbon emissions of mineral insulating oil is 3 918.06 kg CO2e. Moreover

compared with combustion disposal

regeneration disposal significantly reduces the total life cycle carbon emissions of insulating oil. Natural ester insulating oil and mineral insulating oil achieve carbon reductions of 4 085.47 kg CO2e and 3 068.28 kg CO2e

respectively. This results in a unique characteristic of net-negative carbon emissions for natural ester insulating oil

with its total carbon emissions reaching as low as −1 210.57 kg CO2e

and the reason is that the carbon sequestered in the raw materials of insulating oil is released back into the atmosphere after combustion. The total carbon emissions are the sum of the sequestered carbon from raw materials and the carbon from resource inputs. In contrast

regeneration retains most of the sequestered carbon from the raw materials within the regenerated insulating oil. The total carbon emissions are the difference between the carbon from resource inputs and the sequestered carbon from raw materials

resulting in a carbon surplus.