In an effort to find ways to reduce air pollution from existing marine engines, APL is retrofitting one of its containerships with three promising innovations.
The pilot project involves APL’s post-Panamax 64,502-gross-ton, 5,108-TEU containership APL Singapore. The ship’s two stroke, 66,398-hp MAN B&W 11K90MC-C diesel engine will be fitted with:
• a water-fuel emulsion system developed by Sea to Sky Pollution Solutions Corp. in Vancouver, British Columbia; the system is known by the acronym WIFEOD, which stands for water in fuel emulsion on demand
• a new lube oil system
• and an advanced design fuel injector slide valve system.
• a new lube oil system
• and an advanced design fuel injector slide valve system.
The project hopes to demonstrate the feasibility of using these technologies with stricter standards for marine diesels, which will take effect in California in January 2008.
The benefits of adding water to diesel fuel or directly into the actual combustion cylinders have been understood throughout diesel engine developments beginning in the early 1900s. In more recent years, the goal has been the reduction of pollution emissions. The primary methods under development were fuel water emulsification and direct water injection. However, maintaining engine reliability and performance with either system continue to be a challenge.
The WIFEOD system will offer advantages over other existing fuel-water emulsification systems, according to Eric Hutchingame, president of Sea to Sky Pollution Solutions. The WIFEOD water-fuel mixture is produced on demand just before combustion. As a result, storage tank fuel capacity is not reduced, and the risk of water-fuel separation during storage is eliminated.
The introduction of water with the fuel in the engine cylinders lowers the peak combustion temperature. This in turn reduces the formation of NOx and improves the atomization of the fuel, resulting in more complete combustion.
The WIFEOD system is expected to cut NOx emissions by 1 percent for every 1 percent concentration of water in the emulsion. The system allows water content of up to 50 percent, Hutchingame noted. The tests of different concentrations of water will determine the most efficient engine operation level with a goal of achieving NOx reductions up to 25 percent.
Improved fuel atomization will result in less unburned fuel, and therefore less particulate matter, while improving overall fuel consumption.
In addition, retrofitting the slide valves has the potential to cut particulate matter emissions by 25 percent. Slide valves developed by MAN B&W produce a spray pattern that reduces fuel drips from the injector into the cylinder combustion area after combustion.
Changes to the engine lubricating system can cut oil consumption by up to 50 percent, according to APL.
The APL Singapore project is part of the California Air Resources Board’s Maritime Working Group’s public-private program to develop ways to retrofit existing vessels with state-of-the-art, cost-effective emission reduction technologies to meet California’s upcoming environmental standards. For the tests with APL Singapore, public funds will pay for purchase and installation of the control technology and the emissions testing costs, according to the Santa Barbara Air Pollution Control District.
Looking ahead, John Bowe, APL president-Americas, said the three retrofit components of water in fuel emulsion, conversion to the slide valve fuel injectors and installation of the new lube oil system should result in a “significant reduction” in NOx and particulate matter, possibly to the same levels that could be achieved by using low-sulfur diesel fuel.
