As cruise ships venture into sensitive regions, waste and water management technologies have become de rigueur. And they are improving all the time, as Scanship’s innovative waste to energy system shows
If it is not clean, it is not green. The passenger ship industry is embracing a wide variety of waste-processing systems under the umbrella of cleantech as cruise ships push deeper into pristine regions with sensitive ecologies such as the Baltic Sea and Alaskan waters.
One company in the forefront is Norway’s Scanship, a division of Vow ASA, with, at last count, 253 systems in operation on cruise ships and a further 119 on order. But that was before MSC Cruises awarded a comprehensive three-pronged contract to deliver systems for general waste, food and water purification on four of its luxury-class vessels plus options for two more through Fincantieri in late August.
The latest orders give Scanship a bulging orderbook, with a confirmed value of €24.2M (US$28.6M) for seven newbuilds, plus options worth €9.2M for another five vessels. As a bonus, earlier in 2020 Fincantieri awarded the Oslo company another contract, this one for Virgin Voyages.
Simultaneously, Norwegian Cruise Line is retrofitting one of Scanship’s advanced water purification systems on a Nautica vessel that will process all grey and black waste water to the IMO’s blue-chip Marpol standard. Scanship must be doing something right – 19 of Norwegian Cruise Line’s ships are equipped with Scanship’s water purification systems. Scanship chief executive Henrik Badin says, “these contracts convey a strong message that the industry remains focused on the health of our oceans.”
The growth in the expedition cruise sector is boosting demand for cleantech that is keeping suppliers busy. As water technology group Enwa’s global sales director Kjetil Oxnevad tells Passenger Ship Technology, “We have seen a dramatic increase in requests from smaller and more exclusive cruise ships which will operate in more sensitive waters.”
Regulators such as the Arctic Council are putting pressure on the industry to constantly improve cleantech management systems right across the board as they enforce cleaner oceans. In one of the latest developments, in May 2020 China extended the convention on ballast water management to Hong Kong-flagged ships. This means that China, the fourth largest flag administration in the world by shipping tonnage, has extended the convention’s cover to more than 90% of all shipping. It is a measure of the progress in protecting the oceans that the convention now has 83 parties despite only entering into force in 2017.
Passengers as well as regulators are applying pressure. Operators tell PST that crews are constantly being plied with questions about how waste is disposed or handled, and need to be reassured their vessel is not contaminating the oceans.
Water management is a particularly high priority. With 4,000 or more passengers, cruise ships are massive consumers of water. Even a vessel of 2,200 passengers and 900 crew will use about 800-1,000 tonnes of water a day. Scanship estimates at least 200 passengers are required before its systems become viable.
The nub of the technology is reusability. For example, Scanship’s purification system cleans up water to the point that it can be recycled safely for uses including laundry, toilet flushing, ‘technical water’ for machinery, fuel water emulsions, and plant irrigation among other non-drinking and non-recreational uses. Nearly all the ship’s water is handled by the system including from galleys, staterooms, laundry (a big user), grease separators and toilets to the point where it meets the strictest standards. This is the result of a complex, multi-step process installed on board.
Nothing if not idealistic, Scanship is building on its latest flurry of contracts to develop environmentally virtuous energy. “We turn waste into bio-genetic fuels to help decarbonise industry,” Mr Badin tells PST. “And we convert plastic waste into fuel, clean energy and high-value pyrocarbon.”
As good as the boss’s word, after more than a decade including a six-year pilot scheme, the company has developed an industrial-scale onboard system that converts a variety of waste into gas. The system has already been sold to an unnamed cruise ship company, with others showing a keen interest in what is clearly a highly promising technology.
“We hope it is the start of something much bigger,” Scanship chief technical officer Henning Mohn tells PST. The energy is based on a feedstock of dried garbage, food waste and sludge that is created from a proprietary dewatering process developed over the last 20 years. The energy comes in the form of a clean gas which is immediately used in the boiler. Although it is early days for the cruise ship industry, the average fuel savings run at about 2% of total fuel costs, depending on the vessel’s operational profile.
“This is the ultimate,” says Mr Mohn, a Master of Science who has spent much of his working life in waste management. “The bottom line is that a significant amount of energy is recovered and used on board. And it means Scanship becomes much more than a waste management company.”
From any perspective, an onboard energy creation system represents a landmark for the industry, especially when you consider that until now, waste has primarily been treated for easier disposal rather than for energy. And it is certainly a giant step forward from dumping waste in the oceans. The technology is also a milestone in Scanship’s own journey. “We developed our knowledge from land-based applications,” says Mr Mohn. “We started with large hospital incinerators in the 1990s.”
One of the incentives for the company to move into shipping was the industry’s realisation that scientific processing of waste led to healthier ships – unprocessed wet food waste can be highly toxic. Scanship started by creating onboard vacuum tanks to dispose of food waste. In time they developed dewatering processes and other advanced systems such as for water purification, initially in response to the Alaska regulations. Then they combined the management of all three systems – food waste, general waste and water purification into one overarching interface that was sold in a total package.
Scanship has been ahead of the game. For instance, it was one of the first companies to develop a waste water purification system that met the Alaska standards as early as 2003 and, it claims, the first to gain approval for IMO’s standards for the Baltic Sea in 2013. By drying waste and reducing its volume, holding tanks can be smaller. Over the years, Scanship has shrunk the technology, saving valuable space for other more lucrative applications. Its latest technology treats all of the onboard waste water in an area only slightly bigger than the traditional black-water treatment plants. The operational savings add up – many cruise ships no longer have to pay in-port discharge fees.
And to think only a decade or so ago waste from passenger ships was treated as nothing more than rubbish.
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