Recycling of fiber reinforced composite parts leads to a less favorable performance of second life parts in many cases. Moreover, the type of waste, intermediate products and quality requirements towards the recycled material affect the applicability of individual recycling technologies. The presented approach bridges the gap between a specific waste on the one end of a process chain and a possible recycled part on the other end with the help of a knowledge-based approach for the design of recycling routes. These routes frequently include shredding, sorting, separation of matrix and fibers, textile manufacturing and part manufacturing. Individual process steps are modelled in a graph-based design language, considering the fundamental process behavior as well as processing constraints. Rules define the set of valid successors of each process step, so that finally all process chains can be derived based on a given waste type. Two use cases are presented: 1) Given a specific waste, available recycling process routes are explored and the resulting process chain is highlighted. The costs, environmental impact and material properties can then be estimated for the designed process chains. 2) Given a specific waste and intended second life part design, available process routes are explored and similar part designs are extracted from a database of known recycled part designs. Models for costing and environmental accounting have been established in order to support selection of efficient process chains. The presented method is suitable to capture fragmented knowledge about complex recycling processes. The established design language explores and evaluates viable recycling options, so that engineers can retrieve insights without particular knowledge about recycling. This will ease discovery and realization of new second or third life applications, fostering the establishment of a circular economy for fiber reinforced composites.