Mario Michan, a researcher at EPFL's Swiss Plasma Center says nanostructured filters not only reduce sulfur emissions, but NOx emissions as well.
Mario Michan, a researcher at Ecole polytechnique fédérale de Lausanne's (EPFL's) Swiss Plasma Center says that nanostructured filters, when installed on vessel exhaust stacks, could offer a low cost solution for Emission Control Area (ECA) compliance.
Michan says the technology is not only capable of reducing sulfur emissions, but nitrogen oxide (NOx) emissions as well.
The technology is said to utilise thin titanium plates, which are nanostructured to increase surface area and coated with a number of substances in "extremely" thin layers.
Then plates are then arranged to create channels that capture gases as exhaust passes through; "this approach is considered eco-friendly because the substances in the filter are designed to be recycled. And the exhaust gas itself becomes inert and could be used in a variety of products, such as fertilizer."
Mario Michan, Researcher, Swiss Plasma Center, EPFL
Other technologies that have been proposed... only cut down on sulfur emissions without addressing the problem of nitrogen oxide
"Marine diesel fuel is cleaner but much more expensive and would drive up fuel costs by 50 percent, according to ship owners. And the other technologies that have been proposed cannot be used on boats or they only cut down on sulfur emissions without addressing the problem of nitrogen oxide," says Michan.
Current laboratory tests are said to have shown that the nanostructured filter is capable of reducing sulfur emissions to below 1 percent,and NOx emissions to 15 percent below current standards, although the bunker's sulfur content for the tests was not specified.
While current ECA rules require a 0.10 percent sulfur limit, and a global sulfur cap expected in 2020 will mandate 0.5 percent sulfur bunkers, the technology is nevertheless promising.
The Swiss Plasma Center is now said to be working toward bringing the technology's cost down, fitting the filters to large surfaces, and producing a prototype that can be tested according to "real-world conditions."
In March, Peter Hall, CEO of the International Bunker Industry Association (IBIA), said the uncertainty over how many vessels will adopt technology for ECA compliance - rather than simply switch the fuel they used - was adding further complications for refiners trying to determine what quantity of different types of fuel will be required by marine when the eventual 0.5 percent global sulfur cap comes into force.