Environmental impacts in carbon fiber composites life cycles – Focus on recycling and accidents

Rapport, 2025

Carbon fiber reinforced polymers (CFRPs) are gaining importance as a strong and light-weight material in many applications. Lightweighting, such as when CFRPs are used in vehicles to replace heavier materials, often makes it possible to save energy during material transport and product use. When used for reinforcement purposes, CFRPs can provide a more durable and stronger material that reduces material requirements. This means that these materials could potentially give the products they are applied in a better life-cycle environmental performance. A further development of CFRPs is in the form of structural battery composites (SBCs), which are multifunctional carbon fiber composites that carry mechanical load as well as store energy. This could further decrease the mass of, e.g., vehicles, by also replacing parts of the battery, giving additional environmental savings.

CFRPs have only recently entered the larger market, and many questions about their actual handling and performance still remain, particularly concerning their end of life. When future recycling policies (e.g., policies such as European Union Directive 2000/53/EC) enforce the recycling of these materials, it will be important to be able to compare and evaluate different recycling options and for that, both more data and guidance on how to do the assessment are needed. Further, accidents are seldom included in LCAs as LCAs normally focus on average or normal operating conditions. It was suggested in an earlier study by the authors that by including the possible influence of accidents in LCA, biased comparisons can be avoided, but more research is warranted on how this best is included in different studies.

The current research project aims at shedding light on the life-cycle environmental impact of carbon fiber composites, and more specifically, when material recycling and accidents are considered. Research activities focus on the gathering of data for CFRP recycling and accidents as well as method development for inclusion of CFRP recycling and accidents in LCA.

So far, important outcomes include:
·       A list of CFRP recycling options
·       A method for modelling recycling in LCA that considers material quality indicators
·       Life cycle inventories and life cycle environmental impacts of selected CFRP recycling options
·       A list of types of unplanned events in LCA
·       A method for dealing with unplanned events in LCA
·       Inventory data and life cycle environmental impacts of CFRP accidental events

Outcomes have been published in detail in a master thesis, a conference presentation and a journal paper and more manuscripts are currently being put together.