MarEx Print Article: Pressure on Propulsion

The urgency to achieve a cleaner carbon footprint is perhaps felt more strongly in the highly visible passenger vessel sector than anywhere else. Fortunately, it turns out there’s more than one way to reach the Promised Land.
By MarEx Staff

Baseline
Compliance with the International Maritime Organization’s (IMO) new standards governing SOx emissions from ships affects both ship design and operation. The IMO isn’t the only regulator in the game, of course. Local Emission Control Areas (ECAs) also muddy the waters. Meeting SOx emission regulations is, therefore, no longer a lofty goal to strive for; it’s the law. Shipowners do have options. Compliance can be achieved by using low-sulfur fuel, utilizing more efficient engines or by cleaning exhaust gases using SOx scrubbers. Beyond this, regulatory compliance is only one part of the puzzle. Proving that a particular power system meets emissions standards will be quite another.

The Case for Scrubbers
SOx scrubbers have been used, with great success, for shoreside power plants for many decades. Now – and in response to growing pressure from environmental regulations – these devices are being specifically designed for the requirements of ship’s power. And where engine design and lowering sulfur content for marine fuels prove insufficient to meet global and local emission standards, scrubbers can be the ticket to compliance.
Simply stated, a scrubber is an after treatment technology for cleaning exhaust gases of sulfuric oxides. SOx scrubbers can be installed both for new buildings and as a retrofit to existing ships. Combustion units can be diesel engines of any make, type, or application, 2-stroke or 4-stroke. The working principle of freshwater scrubbers is based on a closed loop system. Within the process sulfur oxides in the exhaust gas stream are captured and neutralized by scrubbing water. The scrubbing water is based on freshwater boosted with alkali, typically sodium hydroxide (NaOH). As a result of the chemical process, sulfur oxides from the exhaust gas are neutralized to sulfates in the scrubbing water.

The IMO and other regulators will gradually limit the sulfur content in marine fuels. The most common fuels used in marine diesel engines are heavy fuel oils with sulfur contents typically of 1.5 to 3.5 percent. Such engines can readily burn low-sulfur fuel oils as well, though the associated problems are known and suitable operating guidance is available. Scrubbing exhaust gases is an environmentally friendly and cost-effective alternative for reducing SOx emissions down to 0.1 percent.

A list of current SOx ECAs includes the Baltic Sea, North Sea and English Channel. In the future, this will expand to North America and most likely to other sensitive areas. Beyond this, the IMO Marine Environmental Protection Committee adopted “Guidelines for Exhaust Gas Cleaning Systems,” IMO Resolution MEPC.184(59), in July 2009. The guidelines include rules for certification, verification and documentation of scrubbers and regulations for monitoring and discharge of washwater.

In the ocean-shipping game – and certainly the past 18 months have been difficult – the bottom line is everything. Hence, the cleanest ship in the world is of no value unless it can also turn a profit. With more stringent regulations approved by the IMO, SOx-scrubbing will be an increasingly attractive way of minimizing operational costs by using heavy fuel oil in an environmentally friendly way. In Sox ECAs, the cost savings will be immediate, increasing this year as the price premium for low-sulfur fuel is expected to increase. In 2015, the cost savings will potentially be dramatic, with ROI on unit installation achieved within as little as one year.

The Wärtsilä Scrubber Solution
After performing successfully in a series of tests, the Wärtsilä SOx scrubber has been granted the Sulfur Emission Control Area (SECA) Compliance Certificate by the classification societies Det Norske Veritas and Germanisher Lloyd. Wärtsilä’s solution is the first marine scrubber to be awarded this certification.
The use of scrubbers as an efficient and cost-effective alternative to low-sulfur fuel for reducing SOx emissions from ships has long been questioned. In response, Arnauld Filancia, Director of Marketing Services at Wärtsilä, insists, “This certification demonstrates very clearly that the Wärtsilä scrubbing technology works well and is an efficient solution in marine applications.”

The full-size SOx scrubber test plant was installed on board the MS Suula and was used to clean exhaust gases from the ship’s 4-cylinder, in-line Wärtsilä 20 auxiliary diesel engine. This Neste Oil-owned product tanker operates mainly in the SECA Baltic Sea area, where regulations governing SOx emissions are stringent. Testing was performed with both high (3.4 percent) and low (1.5 percent) sulfur heavy fuel oils and verified that the Wärtsilä system efficiently removes SOx from the exhaust gases. The measurements, which were part of the certification process and made by an accredited independent body, demonstrated a sulfur dioxide removal efficiency rate exceeding 99 percent in all operating conditions, even when using high-sulfur fuel. This high level of efficiency was consistent throughout the load range and with all fuels. The efficiency of nitrogen oxide removal was three to seven percent. The removal of particulate matter was in the range of 30 to 60 percent.
The Wärtsilä SOx scrubber system complies with the new IMO guidelines, adopted in July 2009, for cleaning exhaust emissions from all 2- and 4-stroke engines, including main and auxiliary units, as well as from oil-fired boilers, in both retrofits and newbuildings.

Caterpillar Marine Power Systems: Suddenly a Force in the Larger Cruise Ship Markets
Caterpillar Marine Power Systems, headquartered in Hamburg, has quietly emerged as a real force in the propulsion game for larger cruise ships. Starting from a minor position in a market long dominated by others, Cat has shown an impressive track record in providing power solutions to the big cruise ship builders. The noticeable move for customers who are gravitating to Caterpillar’s MaK-branded engines did not happen by accident.

Under the MaK label, Cat introduced in the late 1990s a 1000 kW/cylinder engine, which was finally made available as a Vee-type version in 2005. This in-line engine, called M43C, is a bestseller for ocean-going ships, utpacing any other brand in its power range with more than 800 units sold so far. Notably, Caterpillar claims to have reduced the number of parts by more than 40 percent compared with its predecessor. Built to meet demanding emission standards, this product fits nicely into the power envelope of today’s cruise ship designs.
Cruise customers like Carnival and NCL seem attracted by Cat’s simple, rugged design: straightforward with fewer multifunctional components that last longer and need less maintenance. The basic long-stroke concept of the MaK engines provides a clean combustion process by design. MaK engines in today’s cruise ships are equipped with FCT (Flexible Camshaft Technology), which allows adjusting valve and injection timing for improved emissions and efficiency. As a result, the M43C can be started up and operated under any load condition without producing any visible smoke.

Ship operators – spurred on by an onerous regulatory process – are setting demanding targets, which will be met by different makers with different technical solutions. At Cat, the general philosophy is, “There is still a lot to invent in engine room and ship design.” Focusing on the larger ocean-going cruise ships built for the main operators, Cat envisions these ships being powered with the MaK M43C line of marine engines. Ships are currently under construction or in service for Costa (Vista Class), Holland America (Signature Class), AIDA (Sphinx Class) and Norwegian (F3 Class), as well as Cunard’s new Queen Elizabeth. In addition, Cat-branded engines are powering cruise ferries and some river cruise vessels.

Caterpillar Motoren is working on a huge investment program costing more than $300 million to optimize production processes and increase capacity up to 2012. A range of projects has already been launched at the German manufacturing sites in Kiel and Rostock and in Guangdong in China. These efforts will result in a doubling of the annual production of MaK marine engines to as many as 1,000 units – up from only 200 just a few years ago.

Yet Another Approach: MTU Engine With SCR Meets Stringent Emissions Standards for a Californi Ferry
A pair of the nation’s greenest ferrie has recently been launched by the Water Emergency Transportation Authority (WETA), California’s agency responsible for developing and operating a waterborne transit system in San Francisco Bay. The vessels feature an eco-friendly propulsion system that includes a compact pollution control unit and a powerful but clean running marine engine from MTU.

The vessels were originally opposed by local environmentalists who contended they would generate more pollution per person than other means of transportation. Studies conducted on three ferries in the Bay Area proved that the diesel engines actually generated less pollution than projected. As a compromise, WETA agreed to a strict pollution specification, requiring cruise emissions to be 85 percent below the EPA’s Tier 2 marine requirements at a vessel speed of 25 knots and 85 percent load—an emissions level one-tenth that of any other ferry operating in California waters.

The emissions specification was placed in the contract WETA offered for four new ferries. After the contract was awarded, the task of meeting the requirement fell to local MTU distributor Pacific Power Products Company in Ridgefield, Washington. “Pacific Power was confident that an environmentally friendly MTU marine engine could do the job with an assist from an accompanying pollution-treatment system,” says Bill Mossey, Corporate Sales Manager for Pacific Power.

Pacific Power chose the MTU Series 2000, which can operate on a blend of biodiesel and ultra-low-sulfur diesel fuel. Even without a pollution-treatment system, the MTU engine exceeds EPA Tier 2 marine emission requirements. “The Series 2000 engine was a key part of our solution to this tough emissions problem,” says Mossey. But beyond being environmentally friendly, it features the highest horsepower in its class. A pair of these powerful engines helps each ferry meet WETA’s demanding 25-knot speed requirement.

Deciding what type of pollutiontreatment system would be paired with the MTU engines to bring emissions down to the required level was Job One. The firm had previous experience equipping a ferry with a system for selective catalytic reduction (SCR), an after-treatment that uses aqueous ammonia in the form of urea to convert smog-producing NOx in diesel engine exhaust into harmless nitrogen gas and water vapor. “An SCR system can be thought of as a catalytic converter for a diesel engine,” Mossey explains.

When used to treat diesel exhaust, SCR can reduce NOx in excess of 95 percent and allow combustion optimization for lowest fuel consumption and particulate matter emissions. Long in use to reduce pollution from stationary sources, the size and weight of SCR systems have made them impractical for many mobile applications. “For stationary applications, space and weight aren’t a concern. But on a ship, they’re important factors,” Mossey notes.

Nevertheless, Pacific Power decided that SCR would be the best pollutiontreatment option to package with the MTU engines. But the WETA ferry application would require a custom-designed treatment solution that would be less bulky and lighter than conventional SCR equipment. Accordingly, a “Compact SCR” system – about one-fifth the size and weight of systems developed for stationary pollution sources – was designed.
Extensive dynamometer emissions testing ensured that the system was feasible. Later, acceptance testing done by WETA confirmed that the MTU engine/SCR package did the job—and then some. Actual emissions were nearly 97 percent below EPA emission standards for Tier 2 marine engines. What’s more, no particulate filter was required to reach the emissions target due to the exceptionally cleanrunning MTU engine. The MTU engine/SCR package proved to be clean enough to meet the WETA requirement even if the engine were burning low-sulfur No. 2 diesel fuel rather than the ultra-lowsulfur diesel fuel mandated by California.
The testing results equate to net tailpipe emissions that would approximate EPA Marine Tier 4 standard levels, which go into effect beginning in 2016. Tier 4 requires a 70 percent reduction in NOx emissions and a 90 percent reduction in particulate matter from current Tier 2 requirements. With the MTU engine/SCR pollution-control package approved for duty, two of the ferries ordered by WETA, Gemini and Pisces, are now in operation in San Francisco Bay. The other two should be plying the same waters by the middle of this year.
Delivered by Kvichak Marine Industries, the vessels are excellent examples of what Kvichak does best: producing “green” boats in the US and internationally. Kvichak’s most recent projects not only include the four WETA passenger ferries, but three all weather fast Dutch Pilot Boats, as well. Notably, the pilot and patrol boats built by Kvichak include materials, construction techniques, and weld designs that allow the vessel(s) to survive the most severe conditions.

Ensuring Compliance and Proving It Too: WRSystems Refines the Art of Continuous Emissions Monitoring
Emissions compliance is only half the battle. Proving adherence to the rules is just as important. In fact, MARPOL Annex VI Maritime Emissions Regulations mandate strict emissions reporting, compliance, and enforcement beginning July 1, 2010.

In direct response, W R Systems, Ltd. (WRSystems) will soon begin marketing its patent-pending Continuous Emissions Monitoring System (Emsys™), a new technology that collects and measures exhaust-stack emissions to help vessels reduce pollutants and meet new environmental regulations.

According to Dave Edwards, Director of WRSystems’ Engineering Services, Emsys™ is the first technology integration of its kind. The laser-driven single enclosure device can continuously monitor emissions and provide automated analysis and data recordings from multiple stacks and boilers. GPS interface data tracks actual vessel position to support regulatory requirements in ECA zones, which usually begin 20 to 25 miles off the coast of major ports and cities. The compact (3’ x 5’ x 2’) and relatively light (400 lb.) device analyzes and records nitrogen oxide (NOx), nitrogen dioxide (NO2), sulfur oxide (SO2), and carbon dioxide (CO2) as well as particulate matter (PM). Emsys ™ is a total emissions inventory system, providing requisite data for the vessel and fleet owners to enter the emissions-trading market. These markets include Green House Gases (GHG) tracking for carbontrading schemes and the European Union (EU) emissions-trading market. As an added bonus, the manufacturer says that Emsys also provides value by assisting in engine optimization for fuel savings.

In the wake of a successful land-based test in August of 2009, the Emsys™ prototype recently passed a trans-Atlantic, at-sea testing. According to WRSystems management, certification by the American Bureau of Shipping (ABS) is projected for February 2010. Expected to go on the market worldwide shortly thereafter, the projected price for Emsys™ is under $140,000 each.

WRSystems is not new to emissions monitoring and sensor systems.For more than a decade it has been developing sophisticated, high-reliability critical sensor systems for the U.S. Department of Defense. Recently, the firm landed a Navy contract that – if all options are exercise – could grow from $27 million to $140 million. WRSystems has also provide high-reliability monitoring systems to the public transit industry.

Steaming Ahead: A Clean Wake in Choppy Waters
The future of energy production on board will probably be less spectacular than we all may wish: The combustion engine will be around for the time being. Regulations and public pressure will eventually lead to zero-emission solutions. To this end, engine makers and others are working to provide the optimum solution, which will not only meet emission requirements but do so economically. With fuel prices expected to escalate in the long term, the fate of engine technology manufacturers will ultimately be tied to the profitability of shipowners. Hence the regulatory pressure on marine propulsion systems eventually promises to yield the positive results from industry that we’ve all come to expect. In fact, you can count on it.

On the Web:
Wärtsilä: wartsila.com
Caterpillar: cat.com.
WRSystems and Emsys™: wrsystems.com
MTU: mtu-online.com
Kvichak Marine Industries: kvichak.com