December 2022 - Bay of Plenty Business News

38 BAY OF PLENTY BUSINESS NEWS December 2022
Scientists explore biogas potential
of partly digested grass from cows
Converting partly digested
grass from the stomachs
of slaughtered cattle into
biogas that could be
used to sustainably heat
commercial greenhouses
is the focus of a new
14-month study at Scion.
It’s hoped the partly digested grass
can one day be blended with food
waste to develop a powerful new
recipe to enhance bioenergy production
for industry – making it less reliant
on fossil fuels, saving money and
benefiting the environment.
Senior scientist and project
leader Dr Suren Wijeyekoon says
it is well known that cows produce
a lot of methane gas when
they belch after grass is digested
by enzymes in their stomachs.
Taking the same grass, known
as ‘paunch grass’, from slaughtered
animal stomachs and using
it to produce methane-rich biogas
is a research opportunity worth
exploring for future bioenergy
production replacing natural gas,
he adds.
“Each cow has about 10-15kg
of partly digested grass in their
first stomach when they arrive in
an abattoir; that grass normally is
disposed of by meat processing
companies, which comes at a cost.
Our research is looking at the
potential to use that waste product
to produce biogas at scale,
taking it from a small batch to a
large pilot study. If successful, it’s
research that can be commercially
adopted by Ecogas.”
The research involving Ecogas,
AgResearch and the Bioresource
Processing Alliance (BPA) builds
on 2017- 2018 Scion, Plant and
Food Research and BPA research
that piloted and de-risked the
technology being used in New
Zealand’s first large-scale food
waste-to-bioenergy facility at
Reporoa. Scion provided bioenergy
expertise to the facility’s
early planning and development.
Once up and running by January
2023, the $30 million stateof-the-art
facility will turn 75,000
Scion scientist Dr Suren Wijeyekoon.
tonnes of organic waste from
businesses and kerbside food
scrap collections throughout the
North Island into sustainable and
renewable clean energy. Owned
and operated by Ecogas, the
new anaerobic digestion plant
sits on 2 hectares of farmland.
After commissioning, food waste
will be converted into biogas,
which can be used to heat nearby
greenhouses, with carbon dioxide
pumped in to enhance plant
growth. Biofertiliser produced
at the site can also be applied
onto more than 1500 hectares of
productive farmland, replacing
imported and manufactured synthetic
fertilisers.
Dr Wijeyekoon says the paunch
grass biogas study started in July
and will be carried out at three different
scales. It will evaluate how
much gas can be produced from
paunch, and how scientists can
enhance that production through
various grass ‘pre-treatment’
methods. Successful methods will
be scaled up from batch to continuous
pilot scale.
Silver Fern Farms provides the
fresh paunch grass for the study.
Scion scientists are then deploying
Scion’s new ‘biomethane
potential test kit’ to assess the biogas
production, which is made up
of about 60 percent methane, and
40 percent carbon dioxide.
Testing will be complete in
October 2023. If successful, it’s
hoped the project will be commercially
adopted.
Dr Wijeyekoon says a longterm
goal is to blend the paunch
grass with food waste to maximise
biogas generation.
“Grass is made up of mostly
cellulose and is metabolised
slowly. Food waste is fast digesting;
together you will improve the
digestion of grass.”
“Ideally, you need the right
cocktail to get the bugs working
optimally – that’s the end game.”
The $385,000 study has been
jointly funded by Ecogas and
the Bioresource Processing Alliance
which works with New
Zealand’s primary sector and science
partners, including Scion, to
get better value out of biological
by-products.
AgResearch is also involved
in the study by exploring the
potential of ‘paunch liquor’ to be
used as a pet food ingredient. The
liquor is considered a valuable
source of proteins, minerals and
vitamins for cats and dogs.
In another part of the project,
Scion scientists will also test the
digestate, the material left over
after the paunch grass is digested
in the bioreactors, for its potential
as a biofertiliser. The team and
Ecogas will partner with a company
to carry out field trials to
assess pasture growth after digestate
is applied.
Dr Wijeyekoon says the study
is a great example of Scion’s
research exploring the benefits of
a circular bioeconomy.
“There are waste management
costs for the disposal of paunch
grass currently. Using that one
feedstock or waste stream, we can
explore a number of new opportunities:
bioenergy production,
bioCO2 for photosynthesis in
greenhouses, digestate for biofertiliser
and pet food ingredient
production.”
The benefits to the environment
and industry are wide ranging.
As well as reducing costs
and climate change emissions
from meat processing companies
by diverting waste from landfill
or composting, the biogas produced
could also satisfy the heat
demands of abattoirs in the future,
he adds.
Ecogas General Manager Alzbeta
Bouskova says the company
is excited to partner with Scion in
the study and explore the potential
of paunch grass as a new clean
energy feedstock and, in the process,
assist the meat industry with
transition to sustainable and circular
principles.
“Ecogas is pleased with the
opportunity to continue to build
commercially desired technical
knowledge,” Bouskova says.
SHANNON TE AO EXHIBITION TŌKU ORA, TŌKU ARA OPENING AT
TAURANGA ART GALLERY
Tauranga Art Gallery was delighted
to announce the opening of Tōku ora,
tōku ara, an exhibition by renowned
Te Whanganui-a-Tara based artist
Shannon Te Ao (Ngāti Tūwharetoa)
in October. Spanning moving image,
photography and performance, Te Ao
creates work that responds to Māori
paradigms, testing the implications
of alternative creative, social and
linguistic models in relation to the
moving image and other performative
practices.
Te Ao is creating a major new photographic
commission for Tauranga
Art Gallery’s atrium which departs
from his predominantly black and
white palette, translating these concerns
into monumental full colour.
Spread across two spaces, the
exhibition also includes Te Ao’s
notable 2020 moving image work Ka
Mua, Ka Muri, which was originally
co-commissioned by Remai Modern
and Oakville Galleries, Canada.
The title of the work is derived
from a whakatauki (proverb) often
cited as a guiding principle within
Māori ideology.
Meaning “to walk backwards
into the future,” it suggests that time
exists on a continuum where past,
present and future co-exist and are
tied together through ancestry and
action.
Tauranga Art Gallery Director
Stephen Cleland says: “Te Ao’s practice
occupies a fascinating intersection
of moving image, photography,
language, and sound. His new exhibition,
devised especially for Tauranga
Art Gallery, ups the ante for his
investment in photography, through
the production of large-scale prints
which more than before approximate
the scale and ambition of his
renowned video installations. We’re
thrilled to be enabling the artist to
achieve a new scale in his practice for
Tauranga audiences.”
Shannon Te Ao is an artist, writer
and curator whose current research
interests include performance and
video art practices. His work has
been presented at several important
exhibitions globally, including
The 10th Asia Pacific Triennial of
Contemporary Art (APT10), QAG-
OMA, Brisbane (2021-22); The 13th
Gwangju Biennale – Minds Rising
Spirits Turning (2021); With the sun
aglow, I have my pensive moods, The
Edinburgh Art Festival (2017); The
11th Gwangju Biennale: The Eighth
Climate (What Does Art Do?) (2016);
and The 19th Biennale of Sydney:
Shannon Te Ao
Ka mua, ka muri,
2020
Two-channel video
with sound
Duration 5m 30s
Cinematography:
Adam Luxton
Installation view:
Oakville Galleries,
Toronto
Photo: Laura Findlay.
Image courtesy of
Oakville Galleries.
You Imagine What You Desire,
curated by Juliana Engberg (2014).
He was the 2016 winner of
Aotearoa’s prestigious Walters Prize,
and is currently Senior Lecturer, Whiti
o Rehua School of Art at Massey University,
Pōneke Wellington.