Scrubber reliability and their emissions reducing efficiency were addressed recently during a technical seminar in which members of the Clean Shipping Alliance (CSA) 2020 reported on the installation and performance of their respective exhaust gas cleaning systems (EGCS). Members agreed that their EGCS were removing more sulphur emissions than the required 0.5%.
Addressing industry delegates at the CSA 2020 event in London, on 20 February, Dario Bocchetti, head of Grimaldi’s corporate energy saving and innovation department, explained the company has fitted the technology to about 70% of its fleet, with installations capable of reducing sulphur emissions down to 0.10%.
A shipowner panel comprising Grimaldi Group, Genco Shipping and Trading, and Spliethoff informed delegates that, despite initial installation problems, there had been little by way of mechanical breakdown, corrosion or non-compliant operation.
All panelists agreed that their EGCS installations were removing substantially more sulphur emissions than the 0.50% required to comply with the global sulphur cap, with Bocchetti remarking that the decision to install the system was to “go beyond the legislation”. Grimaldi Group’s scrubber installations are achieving about 90% up-time.
Ship stability
With exhaust gas cleaning systems weighing between 10t and 100t and taking up additional space, ship stability and cargo capacity must be carefully assessed. However, the panelists advised that only in limited cases, say on some smaller vessels, alternative emissions reducing technology may be the better option.
Bocchetti suggested that there can be some cargo capacity loss, but any losses would be significantly more with an LNG retrofit. He said that retrofitting scrubbers has almost always been possible for about 90% of the company’s vessels.
Spliethoff, which has a variety of ro-ro, multipurpose vessels, and heavy lift vessels fitted out with EGCS has, in some cases, sacrificed a fuel tank to create more space for installation. Apart from a minor deadweight reduction, the company does not see any impact on cargo capability.
The future of scrubbers
In answer to a question from the floor on the future of marine exhaust gas cleaning systems, the panelists agreed that new alternative fuels and propulsion technologies will emerge, but scrubbers could also have a wider role to play.
“Where we will be in ten years is difficult to say,” said Spliethoff’s technical director and a member of the executive board, Arne Hubregtse. “We do need greener fuels, but there are many technologies and challenges to overcome: energy density, storage, operating temperatures and pressures. There is a lot of research going on by engine manufacturers to find a solution.”
Grimaldi’s Bocchetti remarked that any new technology developed will have to be applied on a large scale. He added that scrubber-operating vessels will continue to exist in ten years and the technology could even be developed to reduce other emissions, such as CO2.
