Circularity by Design for Renault Group

Abstract

The European automotive industry is one of the largest consumers of primary raw materials and every year more than six million vehicles reach their end of life in Europe. Although these vehicles are often recycled, the recovered materials are of low quality and only a fraction of recycled plastic re-enters vehicle production. Combined with the dependency on dominant material suppliers and the new EU regulation the industry is being pushed towards circularity and forced to abandon it’s linear model. Renault Group initiated this thesis to explore how circular strategies can be applied within its design practice. The car door was chosen as a use case. The goal of this thesis is therefor to design a circular car door concept that demonstrates the potential of remanufacturing and recycling for Renault Group and its stakeholders within the 2030 sustainable mobility context.

An analysis of the future legislative landscape and Renault Group's existing circular initiatives identified the circular capabilities the company must develop by 2030. It showed that Renault Group is building strong circular infrastructure through The Future is NEUTRAL, but that embedding circular principles into the design of new vehicles remains the least developed capability.

A product-level analysis showed that the door is not designed for the circular economy. This analysis was based on the door's functions, architecture, assembly, disassembly and component value. Together these findings revealed that the door is a subsystem whose components are difficult and time-consuming to extract, whose materials are mixed and joined irreversibly, and in which copper containing components contaminate recycling streams, which forces the recovered metals to be downcycled. These findings define the circularity gap. Renault Group's circular system is in place, but the products entering it are still designed according to linear logic. Closing this gap requires disassembly that is both fast, to make part harvesting and remanufacturing economically viable, and clean, to enable high-quality recycling.

Three concept directions were explored along the three resource cycles of the circular economy (narrowing, slowing and closing) and synthesized into a final design. A new door architecture consisting of an aluminium frame, a monomaterial PP interior panel, and a removable module in which components are clumped and surfaced. Inspired by the Centre Pompidou, the architecture exposes components rather than concealing them, making them visible, legible and accessible. The module can be liberated from the frame in a quick operation, enabling part harvesting for remanufacturing, while the removal of copper containing components improves the recycling quality of the frame.

The architecture was evaluated through validation interviews with stakeholders across the full door lifecycle and a disassembly map comparison. The concept was received as inspiring and new by the design department, technically feasible by the engineering department. Next to this it was perceived beneficial for repair by a mechanic and beneficial for end-of-life recovery by INDRA (vehicle recycler). The disassembly map comparison provided a first indication that the architecture reduces disassembly time.

This thesis demonstrates that circular value is created upstream, in decisions made during design, long before a vehicle reaches its end of life. The proposed architecture should be seen not as a finished design but as a starting point. A new approach to designing car doors and other vehicle subsystems that shows how circularity, applied from the start of the design process, can become a source of inspiration rather than a constraint.