China Bans Discharge From Open-Loop Scrubbers in Coastal Waters

China's maritime authority has banned the discharge of "wash water" used in ships to strip hazardous sulphur emissions from engine exhaust gases from Jan. 1, in an effort to curb pollution of its coastal seas.

The ban on discharges from so-called open-loop scrubbers affects all rivers and ports along China's coastline and includes the Bohai Sea, according to an official from the China's Maritime Safety Administration (MSA).

The measure mirrors a similar move made in Singapore ahead of International Maritime Organization (IMO) rules that will ban ships from using marine fuels with a sulphur content of more than 0.5 percent from 2020, unless they are equipped with exhaust "scrubbers" to clean up sulphur emissions.

"We adopted the ban in designated regions mainly out of consideration to protect the environment and prevent sulphur content pollution in more acidic waters," said the official.

The ban, however, will not be extended to all of China's territorial waters because of the increased costs for the shipping industry, said the official.

China imposed tighter rules from the start of 2019 on sulphur and nitrogen oxide emissions from vessels in coastal areas, Hainan waters, and inland Yangtze and Xijiang river areas, according to the Ministry of Transport.

The wash water ban also took effect on the first day of 2019, MSA said. Ship operators are also not allowed to discharge any residue from wash water or burn it on the ships, it said.

"The bans will limit the use of scrubbers, and therefore high-sulphur fuel oil, in China, suggesting a strong uptick in diesel demand," said research consultancy Energy Aspects in an email alert to clients on Tuesday.

To comply with the ban on wash water discharge in designated waters, shippers will have to switch to a closed-loop scrubber system or to low-sulphur bunker fuels such as gasoil, or diesel, and low-sulphur fuel oil.

Open-loop scrubbers use seawater to capture sulphur from engine exhausts before discharging this wash water back into the ocean after treatment. In closed-loop systems, scrubbing is performed using water treated with additives, recycling the liquid internally. Hybrid scrubbers are a combination of both.

China's effective ban on open-loop scrubbers is similar to action Singapore took in November to outlaw the discharge of wash water in port waters there from Jan. 1, 2020.

Singapore is the world's biggest hub for ship refuelling, or bunkering. Some Chinese port cities are also increasingly targeting the multi-billion dollar bunkering industry, taking steps to show that they will be ready to meet the new IMO fuel standards. 

(Reuters, Reporting by Meng Meng in BEIJING, and Chen Aizhu and Roslan Khasawneh in SINGAPORE; Editing by Tom Hogue)