A vacuum powered system used on cruise ships to reduce food waste could soon be used to separate the waste streams in hotels, hospitals and hospitality precincts.
The average ocean-going cruise ship’s capacity is around 3000 guests, according to CruiseMapper data. On these voyages, kitchen staff need to prepare breakfast, lunch and dinner for holidaying guests and crew.
As with almost all commercial kitchens, food waste is generated not only in the preparation of meals, but also when the plate returns to the kitchen. Unlike most land-based kitchens however, the food waste on a ship will need to be stored until the ship can reach a port or is in a suitable area for discharge to the sea.
Space is an important consideration on these vessels, meaning conventional gravity-based maceration, drainage and collection systems may not be applicable. Additionally, food waste fermentation can begin quickly, producing foul odours and releasing gases that can become health hazards in ship kitchens and refuse areas.
To solve this food waste issue, waste and wastewater management company EVAC implemented a vacuum system in naval and cruise ships to macerate and transport food waste. The technology reduces the amount of labour and customer disruption from multiple bin movements and maximises the amount of waste storage available on a ship.
In-feed stations are located in kitchen areas and places where food waste is generated. The stations each contain a macerator which is able to shred vegetable scraps, bones, fish skins, and other food waste before it’s mixed with a small percentage of water to help create a slurry. A magnet ensures there are no metal contaminants within the system, and then the macerated food waste is then transported through a single 50 or 75-millimetre pipe to a central collection point using a vacuum.
The waste tank can be located anywhere on the ship and is not limited by horizontal movements because transport is made possible using vacuum, allowing flexibility for designers to install the system.
This technology is now being brought on shore to reduce landfill output in large buildings such as hotels and shopping centres by the Australian representatives for EVAC, Australian Vacuum Systems (AVS).
Sustainability Victoria’s Statewide Waste and Resource Recovery Infrastructure Plan 2015-2044 reports the commercial and industrial sector generated 282,000 tonnes of food waste in 2011-12, but only 31,000 tonnes were diverted from landfill.
The plan states food waste feedstocks from the hospitality and hotel sector can have low contamination rates and consistent supply tonnes, making them attractive as base loads for reprocessing, which can lead to increased resource collection.
Chris Herbert, Australian Vacuum Systems National Sales Manager, says the vacuum system reduces the need for odorous and potentially heavy waste trolleys and creates an easy collection point for food waste.
“By separating food waste from the general refuse, it reduces the overall amount required for municipal collection. Further, by macerating the waste into a slurry, it doubles the storage density as more liquid can fit into a cubic metre than solids,” he explains.
“For building developers and operators with hospitality precincts, this has the potential to reduce the collection interval of food waste by 50 per cent,” Chris adds.
When used in a commercial development, the system connects a network of in-feed stations placed strategically throughout a hospitality precinct to a waste tank which can be stored in an out-of-the-way location to maximise space and reduce refuse areas returning valuable plant room to building owners.
When the level of food waste reaches a certain point in the waste tank, it can then be discharged via a suck truck through a single pipe which allows building designers to locate the tank in unusable locations, such as under a vehicle ramp, while still being accessible for collection.
The waste can then be used in a variety of applications, such as anaerobic digestion, or for compost instead of being sent to landfill.
Chris says the direct processing and transport of food waste away from kitchens reduces the requirement for back-of-house bin storage, which means restaurants are potentially able to provide more seating for customers within their tenancy.
“On one project, developers were able to include up to three additional tables into their restaurants, increasing capacity and revenue which significantly increased the return on investment,” he says.
“Additionally, with the introduction of the Queensland waste levy, we expect the system to help businesses reduce their collection fees and future proof the building by providing a separate waste stream.
“It also helps to reduce truck traffic in certain areas around the building, as a collection point can be specifically located away from general traffic.”
The system is custom designed for a building’s unique needs and tenants, though Chris notes it will work best when there is a significant amount of food waste. To assist with its implementation, AVS provides design and engineering along with installation support and maintenance.
Chris says that AVS also trains facilities management teams in its operation to provide a level of self-sufficiency while also being able to offer high-level repair and maintenance.
“Our focus is on using vacuum technology to help solve the challenges food waste presents to the hospitality industry,” he adds.
“By assisting businesses to separate their waste streams, it makes it easier for them to divert food waste from landfill.”
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