Sustainable Sailing Puts Its Sail-Recycling Process to Sweet, New Use

Sails — while manufactured using durable, synthetic textiles such as
polyester, polyethylene terephthalate (PET), aramid and even
carbon fiber to withstand harsh ocean environments and extreme weather
conditions — still tend to need replacing every five years; professional racing
teams can go through several sails per event.

Roughly 2,000 tonnes of PET sails used by the marine sector worldwide are
decommissioned or damaged beyond repair every year, with the majority either
remaining in storage or sent to landfill sites to decompose — which can take up
to 450
years.
And there are currently limited options for recycling these technical-grade
materials.

Sustainable Sailing — a startup established
by two brothers with backgrounds in both sailing and chemistry — is aiming to
find ways to make use of this type of waste.

A research collaboration between the startup and the Sadler
Lab at the University of
Edinburgh recently received funding through Innovate
UK’s bio-based manufacturing
Launchpad
competition for Scotland and is also supported by the Industrial Biotechnology
Innovation Centre (IBioIC). Drawing on the engineered biology and green
chemistry expertise of the Sadler group, the team has identified an opportunity
to use the waste sails as a raw material for high-value chemical compounds
traditionally derived from petrochemicals.

Commonly used in packaging, PET maintains much of its quality and durability
after recycling — so, its recycled form,
rPET,
is a good candidate for packaging producers looking to cut back their use of
virgin plastic. But Sustainable Sailing’s process treats PET sail cloth using
high-pressure steam to break the composite material down into its chemical
building blocks — which can be used in existing industrial and manufacturing
processes. The company initially focused on turning these building blocks into
other types of plastic but is now looking at creating a range of more
sustainable materials, using waste sails as an alternative to virgin fossil
fuels in the creation of high-value chemicals used in everyday products — even,
potentially, food ingredients.

Following prior University of Edinburgh
research
that proved the feasibility of turning single-use PET drink bottles into
vanillin (vanilla flavoring) using engineered E. coli bacteria as a
catalyst, the same process is being applied to assess the viability of recycling
sailing waste for similar chemicals.

“We’re delighted to be part of this collaboration which draws upon our expertise
to test the viability of using a biological system to upcycle plastic fibers
from sails into high-value chemicals,” said Dr Joanna
Sadler, Chancellor’s Fellow
in Biotechnology and founder of the Sadler lab. “The results from our research
have already had major implications for the field of plastic sustainability and
demonstrates the power of engineering biology to address real-world challenges.”

As Dr Joe Penhaul
Smith, founding
director of Sustainable Sailing, explains: “Water sports and sailing have always
been part of our family, so with my scientific background and my brother’s
professional sailing experience we hope to use our skills to tackle the marine
industry’s environmental footprint. Some decommissioned sails are turned into
one-off clothing pieces or
bags,
but there’s no large-scale solution to tackle the waste material. This project
aims to find a new, circular recycling process where sailcloth can be broken
down and repurposed into useful chemical compounds. The added benefit is that
these types of compounds are traditionally manufactured from petrochemicals —
so, marine waste could become an alternative, more sustainable feedstock.

“The next stage of the process is to take it to a much larger scale, as well as
working out the supply and demand dynamics to see whether it would be viable to
have everyday chemicals manufactured in this way. There is also potential to
extract different chemical building blocks for other industrial uses, and we
could see additional types of technical textiles being recycled in this way in
future.”

But … vanilla flavoring made from plastic? Steve
Thomas, associate director
of applied science and industrial biotechnology at Cambridge
Consultants, told Professional
Engineering
that making polyester-derived chemicals food safe is “absolutely possible:”
“Microplastics
would not be the concern for food safety,” said Thomas, who is not involved in
the Sustainable Sailing project. “The output is far more likely to contain
microplastics from the polyester shirt that the person opening the bottle was
wearing than the process itself.”

Sustainable Sailing is also using its process to recycle old sails into new
sails. The company is part of the latest cohort of Transport Research and
Innovation Grants,
funded by the Department for Transport in partnership with Connected
Places Catapult. This grant and development support package will be used to
expand the Sustainable Sails project to cover the vast majority of sail cloths
currently in use globally — processing them in a completely “closed loop,” using
only water and electricity, to return the plastics and fibers back to the
economy.