Sulphur limit looms

Focus on scrubbers as cruise ships trial new systems
Sulphur limit looms

By Susan Parker |

Demonstrating just how fast the industry can move is the recent announcement that Carnival Cruise Lines is placing ships back in Baltimore and Norfolk, having pulled them out due to the North American Emission Control Area (ECA) 0.1% sulphur limit coming into force in 2015.

This about-turn is due to scrubber technology development and the exemptions secured under Regulation 3 Marpol Annex VI by parent Carnival Corporation & plc.
In a statement on 30 January, Carnival Cruise Lines said: “Scrubber technology will be installed on Carnival Pride prior to its Baltimore deployment in spring 2015. This new technology will enable the Carnival Pride to exceed the stricter air emission standards established for operation within the North American ECA.” Earlier in January the cruise brand had announced that a vessel – as yet undisclosed – will be placed in Norfolk, Virginia.

Tom Dow, VP Public Affairs at Carnival, says the company has secured permits from the relevant flag states to allow for the trial of the equipment to proceed for the 42 vessels from various of its brands that will be operating in the North American ECA.

This means the corporation has been granted exemptions from the ECA sulphur requirements whilst the scrubbers (about 100) are being installed and commissioned. The 42 vessels will each be fitted with between two and five scrubbers – depending on the itineraries to be sailed – during scheduled drydocks.

Dow explains: “We trialled one unit on Queen Victoria and will be installing more in 2014. I would consider this first installation as a beta test. Lessons from that will be incorporated into later editions.” All the vessels will be fitted by mid-2016 under an agreement with the Environmental Protection Agency.

Part of the research and development taking place involves the equipment and part of the design. Dow comments: “We are hopeful and we expect that as this technology is refined and developed, we will find it easier to install when the ships are in service so installation is not limited to drydock.”

The scrubber in question is an open-loop system but Carnival has yet to put a name to the manufacturer. The technology is constantly evolving, as Dow explains: “One of the significant advances is the pre-scrubber filtering system which removes contaminants so that after the exhaust goes through the seawater scrubber unit the only adjustment is to pH.”

Until recently the waste water following scrubbing was causing problems in how to clean it sufficiently before discharge. Dow explains that when using seawater in and out, pH adjustment may not be necessary depending on the salinity and temperature of the seawater used for the intake. Even if adjustment is required, he says this is “pretty easy to do compared to removing other solids and contaminants”.

Another significant development with the new generation of scrubbers is that they are much smaller so, instead of having to place them high up in the funnel, they can be fitted in existing spaces where the silencer once was – doubling up as they can for both functions. In addition, being lower in the ship and requiring less water to operate is advantageous from a trim point of view.

Installing the equipment on 42 different vessels with different engine configurations and itineraries will allow the corporation to “rapidly progress the R&D process because we want to bring them to commercial scale as quickly as possible”.

At about US$2m per unit, the investment is significant, says Dow. “The goal of the entire effort is to bring down cost as we become more efficient in fabrication and installation. We think we can do so.” He points out that in 2015, ships not equipped with scrubbers will effectively be using marine gas oil (MGO) all the time when in the ECA. “Depending on the port of purchase and the time of year, the premium on MGO is between 70% and 100%. It is well worth the investment.”

During the development stage, the ships are granted an exemption from the ECA but once installed and working, if the scrubbers are achieving as clean exhaust as required, they will graduate into equivalency – under Regulation 4 Alternative Marpol Annex VI – which has no time limit on it.

Dow concludes: “The beauty of this from our standpoint and the appeal to the regulators is that the end result is better than what can be achieved just using low-sulphur fuels because the scrubber removes particulate matter and carbon. From a health standpoint particulate matter is a problem. It is not often that you can say the solution is better than what was originally required.”

At Royal Caribbean Cruises Ltd, a number of different scrubbers are under test or being fitted to newbuildings. Rich Pruitt, VP Safety & Environmental Stewardship, explains: “The Green Tech Marine system on Liberty of the Seas has approximately 1,400 hours on both open and closed loop. We are continuing to learn from the trial. The system is currently being used to meet the North American ECA requirements of 1.0% but based on our exemption we are routinely below 0.1%.”

While the company has also been testing an Ecospec system on Independence of the Seas, this has been put on hold pending results from the above. For the three newbuildings, Pruitt agrees with Dow that it is “easier to start from a clean piece of paper” than retrofit. In this case Wärtsilä is supplying both the engines and the scrubbers for Quantum of the Seas and Anthem of the Seas, as well as Mein Schiff 3. The latter is a combined system for treating exhaust gases, incorporating desulphurisation equipment and a catalyser with a washwater treatment system. Having one supplier for both is not necessarily the way forward, as he explains: “We are still aggressively trying to find the best overall solution. It is not a ship-by-ship but engine-by-engine decision.”

This article appeared in the Spring/Summer 2014 edition of International Cruise & Ferry Review. To read the full article, you can subscribe to the magazine in printed or digital formats.

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