Millions of tonnes of food go into landfill each year. Food waste image from www.shutterstock.com
Around 4 million tonnes of food reaches landfill in Australia each year. This forms part of Australia’s organic waste, the country’s largest unrecovered stream of waste that goes into landfill.
There’s a missed opportunity here to recover this waste and do something useful with it. In particular, we can use it for energy such as biofuel. This forms part of a broader concept known as the “circular economy”.
In the absence of federal initiatives, state and local governments and communities are developing projects to foster a circular economy that can absorb this and other waste. This would then provide usable products to assist businesses and households and improve sustainability.
Simply disposing of waste in landfill affects households, businesses and governments. It requires time, energy and space, and poses environmental risks. When waste is repurposed for energy and fertiliser, it can give businesses a competitive edge, foster sustainable growth and create jobs.
The circular economy
A circular economy aims to bundle policy and business strategies into a system that works for everyone.
On a wider scale, circular economies underpin food security by reducing and reusing the amount of food waste, utilising byproducts and food waste and recycling nutrients as fertiliser.
While one way of repurposing food waste is to turn it into biofuel, a circular economy does not require all waste to be repurposed. Unwanted food can be given to the needy, or go into further processing. The idea is we extract every joule possible from organic matter, which may require multiple uses.
Some overseas governments have policies that compel businesses to keep their waste out of landfill. These countries are well on the way to developing circular economies. The star performers include Denmark, Japan, the Netherlands, Scotland and Sweden.
In Australia, the federal government has offered no such incentives. Instead, communities are taking it upon themselves to repurpose waste. State and local governments are introducing policies that offer incentives for recycling, or penalties for producing landfill.
There is a growing interest in co-digestion to boost biogas production, particularly for small wastewater facilities.
Co-digestion is the addition of other waste streams such as:
food and drink manufacturer process waste (including waste from the beverage, meat processing, dairy, brewing and wine industries)
greasy waste/fats, oils and greases (from grease trap pump-outs)
residential food and green waste (via trucked collection)
residential/commercial food waste (organics rubbish bins)
food waste (from supermarkets or supermarket chains).
So let’s have a look at recent advances around the country.
Commissioned in 2013, South Australia Water’s Glenelg wastewater treatment is Australia’s first co-digestion facility. The addition of food byproducts such as milk, cheese, beer, wine and soft drink has increased power generation from 55% to 75% of the plant’s power requirement.
The South Australian government is developing a bioenergy roadmap. The aim is to link biomass suppliers in regions to users of energy and help to support local businesses to add value.
Yarra Valley Water’s waste-to-energy facility is a new co-digestion development at Aurora Sewage Treatment Plant, north of Melbourne. It will process 100 cubic metres of waste each day. The waste is delivered by trucks from local commercial waste producers, such as markets and food manufacturing.
Through Sustainability Victoria, the state government is offering funding through the Advanced Organics Processing Technology Grants program, which supports the installation of small-scale onsite or precinct-scale anaerobic digestion technology for processing organic waste.
New South Wales
Australia’s best example of a community-driven circular economy is being developed in Cowra on the Lachlan River, part of the Murray-Darling catchment. This proposal shows the ability of state and local government, industry and farms to pool waste created in and around a country town to produce energy and fertiliser, which can be used within that same geographic circle.
The project will use two processes: anaerobic digestion and thermal recovery through either pyrolysis or torrefication (the breakdown of organic material at high temperature).
At full capacity, the Cowra biomass project will produce 60% of the town’s energy needs.
NSW’s council amalgamation process is also creating opportunities to link more waste producers and energy users through renewables that turn food, household and agricultural waste into power.
The NSW government’s Growing Community Energy grants have already helped the Cowra project.
The drive for communities and businesses to reap the rewards of extracting value from food waste is a result of an emerging trend in infrastructure planning, where the once parallel fields of water management, waste management and energy are teaming up.
It appears CLEAN Cowra and its regional and state equivalents are influencing the direction of federal government policy with relevant priority areas for ARENA being identified.
Whatever the driver, anything that can keep organic waste out of landfill has to be a good thing.
About The Author
Bernadette McCabe, Associate Professor and Principal Scientist, University of Southern Queensland