Oily black smoke belching from Star Ferry vessels plying Victoria Harbour could become a thing of the past if trials of new exhaust-scrubber technology prove successful.
The Star Ferry has already fitted one vessel with a system that uses seawater to remove sulphur dioxide from the black exhaust, and the company is now working with the University of Hong Kong on an enhanced version to remove nitrogen oxide.
The upgrade would substantially reduce the amount of soot pumped into the atmosphere by the firm's ferries and cut the harmful effects of the emissions on the public.
Civic Exchange, the public policy think tank, estimated that about 3.8 million people live in close proximity to Hong Kong port, including Kwai Chung, and risked direct exposure to shipping and port-related emissions high in sulphur dioxide, nitrogen dioxide and other pollutants.
Star Ferry general manager Johnny Leung Tak-hing said the use of the scrubber technology, which has been developed in conjunction with the ferry company, university and a Canadian expert, would offer a more cost-effective solution than using ultra-low sulphur diesel.
A 740-day trial using ultra-low-sulphur diesel onboard the Day Star resulted in several engine-related issues including a 10 per cent loss of power and uneven cylinder liner wear. The low sulphur fuel was also about HK$1 per litre more expensive than conventional marine diesel, adding around HK$1.5 million a year to the firm's fuel costs.
Leung said the seawater scrubber can reduce '90 per cent of sulphur dioxide which is comparable to using ultra-low sulphur dioxide'. The scrubber also 'significantly removed visible smoke' while pollution in seawater used to clean the exhaust emissions was within regulatory limits.
But Leung added the scrubber had less of an impact in removing other pollutants. 'We were not content with the overall result so we are working with Hong Kong University on a nitrogen oxide prototype.'
Leung said the research team hoped to make a submission to the Environmental Protection Department's pilot green transport fund in the next two months to finance the prototype. He hoped a three-month trial to assess the overall operating efficiency of the system could start early next year.
Leung estimated it would cost around HK$1 million to install the integrated emissions scrubber on each of the company's 11 ships. But a final decision whether to invest the money would depend on the results from the trial and the Star Ferry's long-term investment strategy.
The number of years Star Ferry's vessels have been sailing across Victoria Harbour, after services were started by steamboat in 1880