The company plans to expand the program across its fleet in the near future.
Catching plastic and cutting CO2 emissions
Benefits of the technology include the ability to separate the small pieces of plastics and other debris that sometimes find their way into food waste to ensure none of that is discharged. Also, the technology provides more efficient and centralized onsite food waste operations and enhances public health as well as reducing a ship’s carbon footprint by automated and natural processing of food waste.
The biodigesters cut CO2 by using an aerobic digestion process that efficiently breaks down food particles, releasing a translucent, environmentally safe liquid. This limits the amount of greenhouse gas emitted from conventional food waste processing systems.
Testing on 15 ships with more to come
Biodigesters are currently being evaluated on 15 ships with 12 more ships scheduled in coming months across seven brands — Carnival Cruise Line, Costa Cruises, Cunard, Holland America Line, P&O Cruises, Princess Cruises and Seabourn.
Throughout the day, as food scraps are added to the system, a mix of microorganisms, including microbes and enzymes, rapidly break down the organic waste. The machines operate 24 hours a day, allowing for continuous food ‘digestion.’
A stainless-steel 'stomach'
Chris Donald, SVP corporate environmental compliance at Carnival Corp., compared the technology to a large stainless-steel ‘stomach.’
‘Since we serve meals to millions of guests each year, this new green technology can help us significantly reduce our environmental impact and carbon footprint, while also greatly improving our ability to manage non-food waste, including plastics,’ Donald said. ‘We have already seen positive results and significant benefits from these systems, which are technologically advanced yet simple to use.’
Three systems in testing
Carnival Corp. is testing three different biodigester technologies, including systems that evaluate a variety of parameters and produce data such as the weight and volume of food waste digested, the net food waste reduced and the amount of CO2 reduced. All these parameters can be automatically uploaded to a cloud server and remotely monitored around the clock by shipboard and shoreside employees.
The biodigesters are placed in areas like galleys. The systems used in the pilot feature a screen filter at the bottom of each machine that captures any small plastics and other non-organic debris accidentally mixed with food waste.
Aboard the new Carnival Panorama
During an environmental tour of the newly inaugurated Carnival Panorama at Long Beach today, Rich Pruitt, VP environmental operations for Carnival Cruise Line, said the corporation had conducted massive research to hone in on the three technologies currently in testing.
Pruitt showed one of them, the ORCA system in the main galley. There, crew carefully sort food waste by hand before it goes into the machine that looks like a very large top-loading dishwasher. Biochips and microbial mixtures are added, then oxygen is introduced to trigger aerobic digestion. The food breaks down into smaller particles and, eventually, liquid. That goes through a super-fine, 0.5 millimeter screen to capture even the tiniest particles of plastic and other inorganic waste.
Pruitt said the system is capable of processing 50 pounds of food waste per hour, or 1,200 pounds per day.