Article: Route to cleaner shipping

By DAVID FOGARTY

Singapore firm aims to make vessel emissions ship-shape.

WHEN it comes to greenhouse gas emissions, the shipping industry is neither lean nor green.

Ships carry about 90% 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 (CO2) 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.

Shipping contributes about 4% 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 Marine Environment Protection Committee of the International Maritime Organisation (IMO) in 2007 estimated total CO2 emissions from shipping at 1.12 billion tonnes in 2007 and forecast 30% growth by 2020.

The committee 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’ (UN) main weapon to fight climate change.

The European Union will include aviation in its emissions trading scheme from 2012 and has threatened to include shipping from 2013 unless there is a UN-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, sulphur dioxide and NOx, 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% of sulphur dioxide, 80% of NOx and nearly 7% 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.

Sea water 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 US$1mil (RM1.85mil to RM3.7mil) 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 is 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.

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

“If you scrub out 1kg of sulphur dioxide, you produce 2.75 kg of CO2,” he said. But by using highly alkaline seawater, the CSNOX process avoids this side-effect because it neutralises the sulphur dioxide.

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.

“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.– Reuters

This article was taken from: The Star Online: Lifestyle: Focus 14 April 2009