Tag Archives: pollution from ships

Scrubbing Sulfur Pollution

From January 2020, the United Nations International Maritime Organization (IMO) will ban ships from using fuels with a sulphur content above 0.5%, compared with 3.5% now.The rules herald the biggest leap in how ships are powered since they switched from burning coal to oil over a century ago, but vessels will still be allowed to use higher-sulphur fuel if fitted with cleaning devices called scrubbers.  Closed-loop scrubbers keep most of the water used for sulphur removal onboard for disposal at port. Open-loop systems, however, remove sulphur coming through a ship’s smokestack with water that can then be pumped overboard.

Years of studies have examined whether open-loop scrubbers introduce into waterways acidic sulphur harmful to marine life, cancer-causing hydrocarbons, nitrates leading to algal blooms and metals that impair organ function and cause birth defects.  The results have largely been inconclusive and the IMO itself has encouraged further study into the environmental impact of scrubbers.

The stated aim of the new IMO measures is to improve human health..  A study in the journal Nature last year found ship emissions with current sulphur levels caused about 400,000 premature deaths from lung cancer and cardiovascular disease as well as around 14 million childhood asthma cases every year.

Singapore and Fujairah in the United Arab Emirates have banned the use of open-loop scrubbers from the start of next year. China is also set to extend a ban on scrubber discharge to more coastal regions. 

Excerpts from Noah Browning, Going overboard? Shipping rules seen shifting pollution from air to sea, Reuters, Oct. 21, 2019

Cleaning Up Dirty Shipping

Making shipping cleaner is made more urgent by the decision of the International Maritime Organisation (IMO), the United Nations body responsible for the world’s shipping, to reduce the amount of sulphur allowed in bunker fuel from 3.5% to 0.5% by 2020. Sulphur is nasty stuff. When burned, it forms sulphates, which cause acid rain and pollute the air. A paper published in February 2017 in Nature Communications, by Mikhail Sofiev of the Finnish Meteorological Institute, found that the imo’s new rule could stop between 139,000 and 396,000 premature deaths a year.

The trouble is that sulphates also scatter sunlight and help to form and thicken clouds, which reflect solar radiation away from Earth. As a result, shipping is thought to reduce rather than increase man-made global warming—by 7% throughout the 20th century, according to one study. Dr Sofiev’s research showed that this cooling effect could fall by 80% after 2020, with the new low-sulphur standard in place…

The obvious way to offset the loss of sulphur-related cooling is by steep cuts to shipping’s planet-cooking carbon-dioxide emissions. The IMO wants these to fall by half, compared with 2008 levels, by 2050, regardless of how many vessels then ply the seas. But unlike desulphurisation, which is both imminent and legally binding, the CO2 target looks fuzzy and lacks any enforcement mechanism. An attempt to begin fleshing it out, at a meeting of  IMO member states which concluded in London on October 26, 2018 foundered.

One way to cut fuel consumption is to reduce drag by redesigning hulls and propellers. This is happening. In the past five or so years many ships’ propellers have been fitted with tip fins analogous to the turbulence-reducing upturned winglets on aeroplanes.  Further percentage points can be shaved away by smoothing hulls. This means, in particular, stopping barnacles and other creatures growing on them. Tin-based antifouling paints are now banned as toxic to sea life, so paintmakers are returning to an 18th-century solution to the fouling problem—copper.   Hulls can be scraped smooth, too, but restrictions on littering waters with paint chips and species from foreign parts have made such cleaning problematic. This may change, though, thanks to an underwater drone described by its Norwegian maker, ecosubsea, as “a cross between a vacuum cleaner and a lawnmower”. Rather than scour hulls with a metal brush, ecosubsea’s robots blast water at an angle almost parallel with the hull’s surface, which mostly spares paint from abrasion but hits marine growth perpendicularly, and thus hard. 

Many have hopes of returning to wind propulsion, and engineers have devised various modern versions of the sail. None has yet succeeded. A system developed by SkySails, a firm in Hamburg, for example, relied on kites to pull ships along. It was installed on five ships from 2008-11, but proved fiddly to use and maintain…

Some hope to cut marine emissions by employing batteries and electric motors. For transoceanic shipping this looks a long-shot. But local shipping might benefit. Norway, for instance, has started to introduce battery-powered ferries. And a Dutch company called Port-Liner is building electric canal barges for transporting shipping containers. The technology is expensive. Without taxpayer subsidy it would hardly be a runner—a fact also true of the Norwegian ferries.

The problem of shifting emissions around rather than eliminating them also applies to the idea of powering ocean-going vessels using fuel-cells. These generate electricity by reacting hydrogen and oxygen together. Given that electric propulsion more usually disguises emissions than eliminates them, some suggest the most practical approach to reducing shipping’s contribution to global warming is to switch to low-carbon fuel systems rather than conducting a futile search for no-carbon fuels. One alternative is diesel-electric propulsion.  Liquefied natural gas (lng) is another option. 

Excerpts  from Marine Technology of the Future: In Need for a Cean Up, Economist,  Nov. 3, 2018, at 75

The 2020 Deadline for Fuel Oil

Circle January 2020 on your calendar for what could be a major disruption to the energy market and a jolt to the global economy.The origin of the problem isn’t some oil cartel’s machinations, a looming war or even a technological shift — it is a bureaucratic body that few people have heard of: the International Maritime Organization. Just 30 months from now the cargo vessels that are the lifeblood of global trade will be required to cut the sulfur content in their fuel from 3.5% to 0.5%.

Ships move more than 10 billion tons of cargo a year and do it far more efficiently than road or rail, but it comes at a high cost in terms of overall pollution because ships use fuel oil, which is just about the cheapest, dirtiest stuff to come out of refineries. About 9% of all sulfur dioxide emitted globally comes from ships, contributing to acid rain and many premature deaths annually. Even the new cap is 500 times the sulfur content of most road diesel.

Even with significant investment, refiners may not be ready and ships may have to burn more expensive marine diesel.”Marine diesel affects land diesel which affects jet fuel which affects gasoline,” explains Mr. Tallett. That could cause the prices of those fuels to go up by 10% to 20%.

The only solution may be to simply refine more oil, which means increasing overall demand, to get enough low-sulfur fuel out of the world’s refineries. The International Energy Agency worried about the impact in a February 2017 report, yet it assumes many ships will install marine scrubbers to clean the dirty fuel and that refiners will add units to reduce sulfur content — both expensive propositions.

Excerpts from High Seas are to Deliver a Shock to Energy Sector, Wall Street Journal, June 7, 2017