More on the Scrubber conundrum

Mar 01 2019

As shipping enters the final lap in the race towards meeting the IMO sulfur cap by January 2020, the industry faces an expensive dilemma in making ships more environmentally sustainable, a meeting was told.

Some 112 delegates debated the potential of exhaust gas cleaning systems (EGCS) or scrubbers addressing the emissions regulations, at an IMarEST UAE branch seminar sponsored by Kamelia Cleantech, a Unique Group company.

Nikeel Idnani, IMarEST UAE’s branch Honorary Secretary, in his opening introduction, said that shipowners tread with caution in an industry that is no longer awash with money, yet must comply with what the regulators of the IMO have pledged to deliver against a firm timescale.

Idnani argued that scrubber bans ordered by some countries appeared to be merely ‘politically correct’ to follow by environmentalists, without necessarily having a scientific base to back up the decision. Nevertheless, he emphasised that this does not shred the economics of installing the systems, on a ship-specific basis.

In a double presentation, Kaisa Marton (Kamelia Cleantech managing director) and Dr Sharad Kumar (Group Director, Unique Group and Kamelia Cleantech COO) outlined the alternative solutions to comply with the IMO 2020 legislation, including OPEX, CAPEX and opportunity losses for the solutions. They then highlighted the cleaning efficiency required in 2020, including the washwater discharge rules.

While explaining the reaction chemistry between exhaust sulfur in contact with water, Marton admitted that the pH of the scrubbing effluent can be between 2.4 - 4.5 depending on the fuel sulfur content, scrubbing efficiency, amount of water used and engine load.

This could have corrosion implications and environmental challenges in selected locations with brackish waters, such as the Baltic Sea.

The use of closed loop scrubbing can be justified for these areas because the lack of natural alkalinity can be compensated by the addition of chemicals. Nonetheless, Seawater has excellent capacity to buffer changes in pH due to its alkalinity. Seawater salinity is a good indication of its alkalinity.

Dr Kumar explained the pros & cons of U-type and inline, as well as the working principle of open loop, closed loop and hybrid scrubbers.

Following best industry practices, he proposed a holistic and integrated approach to scrubber delivery, including contracting a shipyard for the installation work, an engineering company for the integration engineering, contracting a naval architect to check the designs and vessel integrity enabling seamless co-ordination of the four different parties resulting in an efficient working solution.

Marton highlighted that critical design factors to consider were engine sizes and performance criteria, funnel dimensions and existing space on the vessel, ship systems, ship geometry, class and flag.

For the project planning stage, it is important to factor ship operation patterns and schedules, drydocking schedules, opportunity losses if the ship is taken out of operation, possibilities to carry out as much work as possible while the vessel is in service, available accommodation on board for the riding gang, plus lifting arrangements on board and at strategic ports.

On a practical note, she shared Kamelia Cleantech’s experience with challenges faced during installation and operation and potential solutions and commented on Kamelia’s capability to offer turnkey solutions and on the voyage installation options available.

She admitted that heavy fuel consuming ships, mostly on long ocean passages, were the low hanging fruit from an economic perspective to install scrubbers. With a payback period ranging from six to 18 months, depending on the LSFO premium, amid the commercial realities facing the industry, this option is the more financially astute choice.

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