The Wolfson Centre for Bulk Solids Handling Technology

Scrubbers perform better than required

(Posted on 02/03/20)

Scrubber reliability and their emissions reducing efficiency were addressed in February 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.

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 panel members said that their EGCS installations were removing substantially more sulphur emissions than the 0.50% required to comply with the global sulphur cap.

With almost ten years’ experience operating ECGS, Arne Hubregtse, technical director and a member of the Spliethoff executive board, said: “We have not had any major problems; we don't see any corrosion issues or any breakdown issues. We are satisfied with our decision to install scrubbers and we look forward to operating these systems for a long time. From an environmental perspective, if you look at the total picture, scrubbers are still the best intermediate solution we have until a zero-emission propulsion solution is found.”

Italy’s Grimaldi Group, which operates about 100 EGCS-fitted vessels, reported similar success.

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%.

Bocchetti said the decision to install the system was to “go beyond the legislation”. Grimaldi Group’s scrubber installations are achieving about 90% up-time.

Genco Shipping and Trading, which has installed open-loop EGCS to 17 Capesize bulkers, the most recent of which entered service in January, offered similar sentiment. chief operating officer, Capt. Robert Hughes, explained: “We've had no breakdowns. But a lot of that is due to good planning, planning for performance. You must do the mental heavy lifting ahead of time, chose the right supplier, and identify where there could be some limitations and vulnerability. We haven't experienced any issues.”

While scrubbers have been operating successfully over many years in land-based power stations, the marinization of the technology has led to some concern over corrosion. However, the panellists said this can easily be avoided by applying “proper countermeasures”.

Although none of the panellists’ vessels have experienced scrubber-related corrosion issues, Hubregtse said: “You do need to do your homework. You know what's potentially going to go wrong so focus on that.”

“We operate in a saltwater environment and things do rust out. If you're working on anything in the marine environment, it will break down, so you need to have a plan of action in place as you would with any system,” he said. Ultimately the goal here is investing in a well-trained crew united in their focus on cleaner emissions.”

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 panellists advised that only in limited cases, say on some smaller vessels, alternative emissions reducing technology may be the better option.