March 18, 2009 / 12:27 AM / 10 years ago

FEATURE-Singapore firm aims to make vessel emissions ship-shape

By David Fogarty, Climate Change Correspondent, Asia

SINGAPORE, March 18 (Reuters) - When it comes to greenhouse gas emissions, the shipping industry is neither lean nor green.

Ships carry about 90 percent of global trade, and until recently, such has been the demand for coal, cars and electronics, that there has been little concerted effort to rein in the growth of polluting emissions from ships.

But pressure is growing in the United Nations and from the European Union to make ships more efficient and their smokestacks more climate friendly.

Just a few kilometres from one of the busiest ports in the world, a Singapore firm says it has the answer that can help the shipping industry clean up its act.

Ecospec says it has invented and tested a patented method that removes planet-warming carbon dioxide and nitrogen oxides, sulphur dioxide, which causes acid rain, and soot from ship exhausts.

The process, which uses very alkaline sea water sprayed into the exhaust funnel to scrub out the gases and soot, has already been tested on a tanker and earned the backing of the American Bureau of Shipping.

Inventor Chew Hwee Hong said his firm had already developed non-chemical methods of water treatment and in 2008 was given a challenge by a large Middle Eastern tanker firm to find a way to scrub out CO2 emissions.

The trick was to find a method that didn’t cause secondary environmental damage and cleaned up the other polluting gases in the exhaust as well, he said.

"Today, the Kyoto Protocol and the awareness about CO2 contributing to global warming means you can’t say I don’t care about the rest of the gases. You have to look at the whole thing as one solution."


Shipping contributes about four percent of global emissions from burning fossil fuels, about double the emissions from aviation.

But the industry is less visible to most people than aviation and only very recently faced limits on some of the pollutants in funnel emissions, particularly nitrogen oxides (called NOx) and sulphur dioxide.

Nitrous oxide (N2O) and nitrogen dioxide (NO2) are powerful greenhouse gases. Many new ships have engines designed to emit much lower amounts of these gases, but thousands of older vessels do not, at least not without costly retro-fitting.

An internal report submitted to the International Maritime Organisation’s Marine Environment Protection Committee (MEPC) in 2007 estimated total CO2 emissions from shipping at 1.12 billion tonnes in 2007 and forecast 30 percent growth by 2020.

The MEPC is due to meet again in July and is expected to present a scheme to curb CO2 emissions from global shipping, although it’s unclear if it will be adopted by the IMO in time to be included in a broader climate pact by December.

The pact is expected to be finalised in the Danish capital Copenhagen in December when some 190 nations will try to agree on an expanded deal to replace the Kyoto Protocol, the United Nations’ main weapon to fight climate change.

The EU will include aviation in its emissions trading scheme from 2012 and has threatened to include shipping from 2013 unless there is a U.N.-backed international pact to regulate maritime air pollution by the end of 2011.

While aviation is easier to regulate and monitor, shipping is much tougher. It’s unclear if the flag state, owner or operator are responsible for the greenhouse gas pollution and which agency would assess current emissions or allocate allowances.

Chew said individual methods exist to scrub out CO2, SO2 and nitrogen oxides, but he says his method is the only one to date that can tackle all three, plus clean up the soot.

Tests have shown the process, called CSNOX, can remove about 90 percent of SO2, 80 percent of NOx and nearly 75 percent of CO2, he said.

"We don’t want to use chemicals in CSNOX," Chew explained. "We wanted to use a pure physical method to do it so you don’t cause secondary pollution".

The secret of CSNOX is pure chemistry, says Chew, the firm’s managing director and a marine engineer by training who nearly failed chemistry in high school.

The process uses electrolysis and ultra-low frequency waves to raise the alkalinity of sea water to a pH of 10 from a normal level of 8.1. Kitchen bleach has a pH of about 13, while battery acid is at the other end of the scale at about 0.

Seawater is pumped into a tank, the alkalinity is quickly raised and then the water is sprayed into the exhaust funnel where the dirty water is collected, filtered and pumped into an aft tank for further processing.

It would cost between US$500,000 and about $1 million to fit the system to most ships.


Chew said the water that is pumped back into the sea is more alkaline than normal and contains sulphates, nitrates and carbonates that sea life need.

This was a beneficial byproduct because the world’s oceans are becoming more acidic as global atmospheric levels of CO2 rise from burning fossil fuels.

Oceans are a major carbon sink, soaking up large amounts of CO2 in a process that creates carbonic acid. Recent Australian research has shown that rising acidity has trimmed the shell weights of tiny marine animals.

Exiting methods to remove sulphur dioxide from ship exhausts release CO2, Chew explained. A Canadian study found that removing SO2 from ship exhausts actually contributed to global warming.

"If you scrub out one kilogram of SO2, you produce 2.75 kg of CO2," he said.

But by using highly alkaline seawater, the CSNOX process avoided this side-effect because it neutralised the SO2.

Ecospec, which first announced details of the CSNOX process in January, has since received nearly 60 enquiries, among them from major shipping lines and oil companies. A firm that invests in projects that could yield tradable carbon credits was also among those interested.

"The trend is just irreversible. You have to go this way. You can’t be a ship builder without knowing how to install or how to design (emissions-control technology)," Chew said.

He said the company was now looking to adapt the process to clean up emissions from power stations, steel and cement makers and pulp-and-paper mills, as well as rubbish incinerators.

That would be a major growth area for the firm and potentially lucrative, since around 90 percent of mankind’s greenhouse gas emissions come from sources onshore.

(Editing by Megan Goldin)

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