Piana - Filtre à Particules

Piana's particle filter


La Méridionale, historic shipping company serving Corsica, innovates to better its environmental performance. It is the first-ever shipowner in the world to have installed and tested a particle filter on-board one of its ferries, Piana, which sails to Ajaccio.
This state-of-the-art solution significantly reduces sulphur oxide (SOx) emissions and over 99.9% of particulate matter.

Towards more eco-friendly sea transportation

Since 1st January 2020, the IMO 2020 regulation has imposed a sulphur content limit in the Mediterranean.

Sulphur oxide emissions must not exceed 0.5%. To achieve this, the majority of ferries linking Corsica to the continent are fitted with water-based exhaust gas cleaning systems known as scrubbers, to capture toxic particles.

Although some use "closed" circuits, storing contaminated water and waste on-board that will be treated once on-land, other less virtuous discharge polluted water into the Mediterranean.


Development of the first particle filter

After researching and assessing the technologies used in the land-based waste treatment industry, our engineers chose a tried-and-tested solution developed by two world-renowned players, Solvay and Andritz, to "marinize" their dry exhaust-gas desulphurization technologies: the particle filter was created!

Tried-and-tested technology to reduce sulphur oxide from our ferry to Ajaccio

The particle filter fitted on Piana works as follows: 

Piana - Schéma de fonctionnement du filtre à particules
Piana - Schéma de fonctionnement du filtre à particules
  1. Sodium bicarbonate powder (neutral reagent for humans and the environment) is injected into the exhaust-gas manifold at the engine outlet
  2. The sodium bicarbonate chemically reacts on the sulphur oxides present in the gases by neutralizing them and capturing the particulate matter and heavy metals.
  3. The contaminated bicarbonate is stored on-board the ship during the Marseille-Ajaccio crossing, then treated on-land in a waste recovery facility. Once cleaned, the bicarbonate can be reused. 

Result: the filter reduces particulate matter emissions by over 99.9%!

This innovation is part of La Méridionale's initiative for sustainable development and environmental protection. The shipping company has rolled out tangible solutions on-board its ships to Corsica such as the REPCET system for observing and tracking cetaceans and CENAQ, its electrical shore-to-ship power (SSP), to reduce its business footprint. 

This commitment to protecting the Mediterranean was awarded the French shipowners association (Armateurs de France) Blue Charter Trophy (in 2013 and 2018) and the Sustainable Tourism Prize (Palme du Tourisme Durable) in 2018. 

In September 2021, during the 5th edition of the French "Port du futur" (Port of the Future) awards, organized by Cerema (French Centre for Studies on Risks, the Environment, Mobility and Urban Planning), La Méridionale won the "Equipment Award" for implementing its innovative particle filter on Piana.