The maritime industry’s emissions statistics tell an ugly story. They show that, by 2050, shipping operations may generate up to 17% of the world’s carbon dioxide emissions unless decisive measures are taken. Aviation and shipping together are anticipated to account for almost 40% of global carbon dioxide emissions.

To stave off the environmental effects of shipping, stricter limits have already been imposed on sulphur oxide emissions, and these restrictions are likely to expand in the near future. Accelerating global warming is encouraging companies to make sustainable decisions and reduce the environmental impact of maritime operations voluntarily.

Scrubbers are environmentally-friendly, cost-efficient investments

To meet the stricter limits for sulphur within the Sulphur Emission Control Area (SECA), maritime companies must either use low-sulphur fuel or an exhaust gas cleaning system. Low-sulphur fuel is more expensive than the standard heavy fuel oils.

‘A scrubber system allows a ship to use cheaper fuel and the shipping company does not have to worry about any fluctuations in oil prices having an impact on the company’s costs. As a means of reducing emissions, scrubbers are as effective as changing to low-sulphur fuel,’ explains Mertjärvi.

Some ships that normally use cheaper fuel with a higher sulphur content change to low-sulphur fuel before entering the SECA area. This solution is not without its risks because fuel changeover may cause a failure in the main engine and result in a hazardous situation in bad weather. These risks can be avoided with a scrubber.

Making a durable scrubber expansion joint requires experience and the right materials

Expansion joints are an essential component in the scrubber. Manufactured in Ylöjärvi in Finland, Masino’s expansion joints are a result of more than four decades of product development. The materials used for them have been approved by a maritime classification society.

The materials are among the most critical properties of an expansion joint, and a manufacturer must have expertise in strength calculations and access to the correct tools for processing the metal. Not all materials behave the same way when the bellows of the expansion joint are bent.

‘Even though scrubber technology is a relatively new innovation in the maritime industry, we have decades of experience of making expansion joints for other industrial applications. We know the materials used and how they should be processed. We know which metals are resistant to the mechanical and chemical wear that scrubbers and expansion joints are typically exposed to,’ says Mertjärvi. 

For example, an unsuitable material may corrode prematurely. A hole in a corroded bellow may allow exhaust gases to enter the indoor spaces of the vessel.

‘An expansion joint made of an unsuitable material may have to be replaced after a couple of months. The worst case scenario is that the ship has to be docked for this.’
– Jussi Mertjärvi, Sales Director, Masino Industry

Masino delivers expansion joints to Asia and Europe for use in a wide range of scrubbers made of various materials. The company also stores materials to enable it to deliver products on a tight schedule.

An experienced scrubber supplier factors in the limited space available on a ship

Particularly when retrofitting a scrubber to a vessel, a supplier must take space limitations into account. Mertjärvi is often personally involved in the design of scrubbers. One way of saving space is to make the pipe system simpler.

‘We always design the scrubber and expansion joints installed in it in collaboration with the scrubber supplier. This way, we can avoid pipe systems that are unnecessarily long or convoluted, which also makes the system more reliable,’ explains Mertjärvi.

Fact box

• In 2015, the highest permitted sulphur content in shipping fuel was reduced from 1.00 to 0.10 per cent.
• Currently, these restrictions only apply to the SECA (Sulphur Emission Control Area).
• The SECA area covers the Baltic Sea, the North Sea, the English Channel and sea areas extending 200 nautical miles offshore from the United States and Canada.
• These restrictions are likely to be extended to other sea areas in the near future.