Scrap hulls become new boats in GRP recycling alliance

Chomarat, a two-time Boat Builder Award winner, has spent the past 18 months as a key partner in an industrial alliance working to establish a viable circular GRP manufacturing model for the marine industry.

The group includes Groupe Beneteau, Veolia, Composite Recycling, Arkema and Owens Corning, each handling a different link in the chain from scrap collection through to finished laminate. Early beneficiaries of the lower carbon impact of the scheme include the Jeanneau Sun Fast 30 One Design and the Beneteau Oceanis 60.

Most recently, the Excess 11 catamaran has joined that list. It now uses recyclable, low carbon resins along with 45 percent recycled glass fibres.

Judges at last year's IBI Metstrade Boat Builder Awards for Business Achievement named the alliance Sustainability Project of the Year. Their assessment was blunt: "This initiative harnesses powerhouses in the field of composites and material recycling and is arguably one of the most important sustainability projects we have seen in the history of the awards."

The process runs like an assembly line. Veolia collects composite production waste and brings it to a site in Western France for recycling. Composite Recycling then runs that scrap through its next generation pyrolysis technology, separating and recycling it into reclaimed glass fibres and oil.

From there, Arkema transforms the oil into its Elium recycled resin product. Owens Corning produces new glass fibres, and Chomarat uses that output to produce new fibreglass reinforcements. Groupe Beneteau then incorporates these recyclable composite materials, including Arkema's Elium resin and mat containing recycled fibres, into boat manufacturing, closing the loop.

In an update in June this year, Groupe Beneteau reported it had already used 12.6 metric tons of Elium resin in the construction of new boats, along with 14 metric tons of recycled and natural fibres thanks to another collaboration with Chomarat using its glass/hemp hybrid product TER²A MAT. The estimated CO2 savings from the use of resin alone are 70 percent.

Chomarat's supply of recycled GRP mat to Groupe Beneteau predated the establishment of the industrial alliance by at least two years, forming in effect the first links in the chain. Chomarat was already working closely with Swiss company Composite Recycling soon after this 2021 start-up got its first processing unit into action, an initiative that was recognised as the Boat Builder Award's Sustainability Project of the Year in 2023.

Composite Recycling's mobile plant is carried within a 30ft container capable of being transported by standard waste disposal trucks. It recovers fibres using the pyrolysis process. The vapour given off in the oxygen-free chamber is condensed to recover oil, which can be used to make new resin or other substances. Gas, another product of the process, is used to power the plant, partially or completely.

The plant can process large pieces of waste GRP, with an eventual processing target of six tons per day. As a result, recovered fibres are potentially as large as the item recycled rather than chopped up, enabling them to be rewoven. This also allows the plant to use a mix of sources, from chopped-up old hulls and superstructures to manufacturing scrap and old mould tools.

Anywhere between 10 and 30 percent of the laminate used to create a boat can end up in the scrap bin due to trimming and cutouts. The ratio of material emerging from the pyrolysis process depends on what is fed in. Pre-1990s vessels have a much higher ratio of resin to glass compared with mouldings made using modern infusion techniques.

Speaking about the launch of the alliance, Business Unit Manager Vincent Cholvy said: "Chomarat is committed to advancing composite sustainability while maintaining the highest standards of performance. This project is an important demonstration of our ability to provide tangible recyclability solutions benefiting our operations, our customers, and our industry's collective goal of achieving end-of-life circularity."