(www.MaritimeCyprus.com) One of the major global environmental concerns today is the air pollution from maritime transportation. One of the main elements of pollution are the sulphur emissions (SOx), which exist due to the presence and burning of sulphur compound in the fuel on board ships.
The shipping industry is among the world's biggest sulfur emitters, with sulfur oxide content in heavy fuel oil up to 3,500 times higher than the latest European diesel standards for vehicles, and environmental groups.
THE GOAL OF IMPROVED ENERGY EFFICIENCY
The aim of improved energy efficiency for reduced air emissions can notably be achieved through actions in two main directions, at the level of design and at the level of operation of the vessel.
New strategies and technologies aiming at reducing ships' fuel consumption are currently a
priority for the industry. Some of the new technologies are the air cavity systems, wind power, fuel additives, twin propellers, new propeller blades, recovery of waste gas heat, and others. The cost related to new technologies can be divided into capital costs (construction, manpower, license fees, delivery of the installation, etc.) and operating costs which relate to annual expenditure.
IMO COMES IN FRONT
The International Maritime Organization (IMO) has approved and adopted a comprehensive set of guidelines to support the consistent implementation of the lower 0.50% limit on sulphur in ships’ fuel oil, which has entered into effect on 01 January 2020. Related draft MARPOL amendments were also approved.
The 2020 rule intend to bring in considerable benefits for the environment and human health. The stricter limit will be applicable globally under IMO’s MARPOL treaty. (In designated emission control areas (ECAs), the sulphur limit will remain at 0.10%.)
The 01 January 2020 implementation date was adopted in 2008 and confirmed in 2016. IMO has been working with Member States and the industry to support implementation of the new limit, including the preparation of amendments to MARPOL Annex VI and development of guidance and guidelines.
Enforcement, compliance with and monitoring of the 2020 sulphur limit is the remit and
responsibility of States Party to MARPOL Annex VI. Most ships are expected to utilize new blends of fuel oil which will be produced to meet the 0.50% limit on sulphur in fuel oil or compliant marine gas/diesel oil.
The IMO Marine Environment Protection Committee (MEPC), meeting for its 74th session adopted the 2019 Guidelines for consistent implementation of the 0.50% sulphur limit under MARPOL Annex VI, Resolution MEPC.320(74) - with sections on the impact on fuel and machinery systems resulting from new fuel blends or fuel types; verification issues and control mechanism and actions, including port State control and samples of fuel oil used on board; a standard reporting format for fuel oil non-availability (fuel oil non-availability report (FONAR); and possible safety implications relating to fuel oils meeting the 0.50% sulphur limit.
THE 2020 CHALLENGE
On and after 01 January 2020, the MARPOL permitted limit for sulphur content in ships’ bunker fuel oil has been reduced from 3.50% mass by mass (m/m) to 0.50% m/m for ships operating outside designated emission control areas.
The MARPOL Emission Control Area (ECA) limit of 0.10% still apply, as will any applicable local regulations.
The IMO’s Marine Environment Protection Committee (MEPC 73) has approved a prohibition on the carriage of noncompliant bunker fuel which has entered into force on 1 March 2020
(Regulation 14 MARPOL Annex VI), with certain caveats.
Ships fitted with exhaust gas cleaning systems (scrubbers), which are designed to remove sulphur oxides from the ship’s engine and boiler exhaust gases in order to reduce sulphur emissions to a level not exceeding the required fuel oil Sulphur limit, can continue to carry fuel with a sulphur content of more than 0.50%.
The IMO MARPOL regulations limit the sulphur content in fuel oil. So, ships need to use fuel oil which is inherently low enough in sulphur, in order to meet IMO requirements.
Refineries may blend fuel oil with a high (non-compliant) sulphur content with fuel oil with a sulphur content lower than the required sulphur content to achieve a compliant fuel oil.
Additives may be added to enhance other properties, such as lubricity. Some ships limit the air pollutants by installing exhaust gas cleaning systems, also known as “scrubbers”. This is accepted by flag States as an alternative means to meet the sulphur limit requirement.
These scrubbers are designed to remove sulphur oxides from the ship’s engine and boiler exhaust gases. So, a ship fitted with a scrubber can use heavy fuel oil, since the sulphur
oxides emissions will be reduced to a level equivalent to the required fuel oil sulphur limit.
Ships can have engines which can use different fuels, which may contain low or zero sulphur. For example, liquefied natural gas, or biofuels.
For more information, click on below image to download the Guidance paper:
Source: Dromon Bureau of Shipping