Maritime traffic is the single largest contributor to air pollution – a single cruise ship emits as much pollution as one million cars. Several technologies are being explored to reduce the pollutants in the exhausts of ships’ diesel engines. Accelerator scientists have proposed a solution that involves breaking down particulate matter as well as molecules of sulphur and nitrogen oxides with an electron-beam accelerator of a few hundred kilovolts, before safely extracting them using water. The ARIES (Accelerator Research and Innovation for European Science and Society) Horizon 2020 project, coordinated by CERN, is working on a real-scale test of this technology.
A first test was performed recently on an old and rusty Soviet-era Latvian tugboat named Orkāns (“storm” in Latvian), moored at the Riga shipyard on the Baltic Sea. The small vessel, procured by the Riga Technical University in Latvia, has an old but powerful engine that could easily be made available for the duration of the tests.
A long pipe, equipped with several detectors, connected the tugboat to an accelerator-on-a-truck that was provided by the Fraunhofer FEP of Dresden in Germany. On the truck, the exhausts were treated in a specially built chamber, with the electrons from the accelerator inducing molecular excitation, ionisation and dissociation to break down the pollutant molecules. Before finally being released into the air, the pollutants from the exhausts were washed out using water in a small “wet scrubber”, designed and built by the Institute of Nuclear Chemistry and Technology (INCT) of Warsaw in Poland, who originally proposed this novel accelerator-based approach.
This long pipe actually connects two worlds, the world of shipping and the world of scientific particle accelerators. Their technologies and their languages are entirely different, but if we succeed in having them working together, we have the potential for a great advance.
– Test supervisor Toms Torims, Riga Technical University
The first measurements confirmed the expected reduction in pollutants. The final results will be made available only after a full analysis has been carried out at different engine powers and operating conditions. The data collected by this experiment will be used to finalise the proposal for the next step in the progress of this technology. A dedicated project will be submitted to Horizon 2020, with the goal of installing and testing a specially designed accelerator on a real cargo ship, to be made available by the Italian Grimaldi shipping company.