Life cycle assessment and energy intensity of CFRP recycling using supercritical N-butanol

Abstract

Recycling carbon fiber reinforced polymer (CFRP) waste is unavoidable for the sustainable manufacturing and cost reduction of CFRP products. Supercritical fluid technology is an emerging chemical method for recycling CFRP waste, but its energy intensity and environmental implication are limited understanding. In this paper, the energy intensity and environmental impact of supercritical fluid technology were quantitatively assessed in CFRP recycling process. Then, the life cycle assessment (LCA) method was used to analyse the life cycle environmental impact of CFRP in two scenarios, scenario (a) using conventional waste disposal method, while scenario (b) with CFRP waste recycling process. The results show that the energy consumption of CFRP waste recycling is 49.21 MJ/kg using the supercritical n-butanol method, which is far lower than that of virgin carbon fiber production (286 MJ/kg). Scenario (b) with CFRP waste recycling has a lower impact than scenario (a) at nine environmental impact categories, including a 26% reduction of global warming potential. Besides, the energy consumption of the supercritical n-butanol method is 31% lower than that of the steam thermolysis method (71.64 MJ/kg) in recycling 1 kg of CFRP waste, which validates that the supercritical n-butanol method is a potential strategy for recycling CFRP waste.