Environmental Technology

The Greenhouse gas issue

Paul Gunton
Paul Gunton

09 November 2018

The Greenhouse gas issue

In recent years the issue of climate change, supposedly caused by the emission of greenhouse gases most notably carbon dioxide, has had an impact on many areas of industrial and social activity around the globe. There are other gases which are considered as causes of global warming but for some reason attention of regulators and politicians has been almost solely focussed on carbon dioxide.

Carbon dioxide or CO2 is an inevitable product of the combustion of any fuel containing carbon which is most fossil fuels including LNG. The air used to support combustion contains oxygen and this will combine with the carbon in the fuel to produce CO2 and other compounds. Any nitrogen in the fuel will be converted to NOx, hydrogen to H20 and sulphur to SOx.

Effectively, the only means of reducing CO2 while still burning fuel oil is to burn less which is the intention of the efficiency regulations developed by the IMO.

In 2011, after extensive work and debate, IMO adopted mandatory technical and operational energy efficiency measures; The energy efficiency design index (EEDI), Ship energy efficiency management plans (SEEMPs) and the energy efficiency operational index (EEOI) which were included in Annex VI and entered into force on 1 January 2013.

These measures are aimed at reducing the amount of CO2 produced per unit of work done which is crudely measured as moving one tonne of cargo over a distance of one kilometre. The EEDI mandates a regular reduction for new ships at five yearly intervals with the current framework due to cease in 2025 when ship emissions should be around 30% below those of vessels in service when the regulation began.

At MEPC72 in April 2018, the IMO announced an ambitious (some might say impossible) target for decarbonising the shipping industry. In particular, it set out the following programme of ambitions:

  • Carbon intensity of the ship to decline through implementation of further phases of the energy efficiency design index (EEDI) for new ships.

· Review with the aim to strengthen the energy efficiency design requirements for ships with the percentage improvement for each phase to be determined for each ship type, as appropriate;

· Carbon intensity of international shipping to decline

· To reduce CO2 emissions per transport work, as an average across international shipping, by at least 40% by 2030, pursuing efforts towards 70% by 2050, compared to 2008; and

· GHG emissions from international shipping to peak and decline

  • To peak GHG emissions from international shipping as soon as possible and to reduce the total annual GHG emissions by at least 50% by 2050 compared to 2008 whilst pursuing efforts towards phasing them out as called for in the Vision as a point on a pathway of CO2 emissions reduction consistent with the Paris Agreement temperature goals.

As things stand, it is impossible to completely decarbonise shipping as even the cleanest of fuels presently available do produce some CO2 and in some cases, the benefit compared to oil fuels is actually quite negligible. For the short to mid-term future these fuels may provide a bridge towards a lower carbon future but not much more. In the long-term other technologies would need to be developed.

US – a law unto itself

Concurrent with the development of MARPOL before emissions to air were included, the US was introducing its own regulations in the form of the Clean Water Act (CWA) passed by the US Congress in 1972 and covering cleaning up the territorial waters of the US. This was done through the National Pollutant Discharge Elimination System (NPDES) permit programme which controls water pollution by regulating sources that discharge pollutants into the nation’s waters. In most cases, the NPDES permit program is administered by individual states but for matters extending beyond individual states, the Environment Protection Agency (EPA) is the governing body.

Section 301(a) of the CWA prohibits the discharge of any “pollutant” unless authorised by an NPDES permit. Shortly after the enactment of the CWA, the EPA issued a regulation that exempted from NPDES permitting “any discharge of sewage from vessels, effluent from properly functioning marine engines, laundry, shower, and galley sink wastes, or any other discharge incidental to the normal operation of a vessel”.

After the turn of the century, environmentalists began legal actions in some states demanding ships should not be exempted from the regulations. In December 2003, the California federal district and appeals courts ruled that the EPA had exceeded its authority when it excluded ships’ discharges from the NPDES permitting system.

As a consequence EPA had to implement a permit system for a wide variety of vessel discharges which would affect all US-flagged vessel and foreign-flagged vessels trading to the US. This resulted in the introduction in 2008 of the Vessel General Permit (VGP) that would apply to all affected vessels whose owners filed a Notice of Intent. A VGP provides ‘NPDES permit coverage nationwide for discharges incidental to the normal operation of commercial vessels greater than 79 feet (24m) in length’.

The initial VGP did not cover ballast water and in the fact sheet that it issued as a guide to the VGP, the EPA emphasises that it fought efforts to require incidental discharges to be permitted not because it dismissed the significance of aquatic invasive species, or other environmental hazards resulting from these discharges, but rather because, in its view, permitting was not the best or most efficient way of addressing the problem. The EPA notes that Congress has already enacted legislation that directed the US Coast Guard, rather than the EPA, to address and come up with a regulatory programme for the discharge of ballast water and other discharges, and that nothing in the CWA prevented individual states from coming up with regulations to control ballast water discharges under state law.

In 2013, a new version of the VGP was introduced which should have run until 2018. This permit regulates 27 specific discharge categories and also provides for improvements to the efficiency of the permit process and clarifies discharge requirements. For the first time, the final 2013 VGP contains numeric ballast water discharge limits for most vessels. The permit generally aligns with requirements contained within the 2012 US Coast Guard ballast water rulemaking. Additionally, the VGP contains requirements to ensure ballast water treatment systems are functioning correctly. The final permit also provides additional environmental protection for certain vessels. For example, certain high-risk vessels entering the Great Lakes must conduct additional management measures to reduce the risk of introducing new invasive species to US waters. More details of the US rules pertaining to ballast water can be found in the dedicated ShipInsight ballast water guide.

Of far more interest to this guide, the final VGP also contains more stringent effluent limits for oil to sea interfaces such as propeller shaft seals and also exhaust gas scrubber washwater. These will be detailed in relevant chapters of this guide. EPA has also amended several of the VGP’s administrative requirements, including allowing electronic recordkeeping, requiring an annual report in lieu of the one-time report and annual non-compliance report, allowing combined annual reports for some vessel operators. The latest version of the VGP regulations and additional documents as well as any relevant notices can be accessed at the following website http://water.epa.gov/npdes/vessels-vgp

In September 2018 it was recognised by the US authorities that the renewal of the VGP regulations would not be completed in time to introduce on schedule. Thus the existing rules were extended to ships already covered by a VGP and those without recommended to apply before the end of the year or risk being excluded from US waters.

Initiatives elsewhere

Other areas of the globe either individual states or regional groupings also make regulations that affect shipping and result in new technology being needed onboard. Arguably the area with the most regulation is the EU which frequently seeks to impose requirements in excess of those covered under IMO rules or earlier than the IMO deadlines. This is despite the fact that individual member states of the EU are signatories to IMO conventions and codes.

One area where this is best exemplified is in connection with sulphur levels in fuels. The basic EU legislation for regulating sulphur emissions from ships was Directive 1999/32/EC. This was amended by Directive 2005/33/EC, which designated the Baltic Sea, the North Sea and the English Channel as sulphur emission control areas (SECAs) approved and adopted by the IMO and limited the maximum sulphur content of the fuels used by ships operating in these sea areas to 1.5%. The fuel standards also applied to passenger ships operating on regular service outside the controlled areas.

From 1st January 2010 when the 2005 directive came into force, as well as reinforcing the limits of sulphur for vessels operating in SECAs and limiting the sulphur content of fuels used ashore in the EU, it also introduced legislation governing the maximum sulphur content of fuels used by inland waterway vessels and ships at berth in Ports which are part of the European Community. The limit for ships in ports was set at 0.1% Sulphur, which is the maximum sulphur content of Gas Oil under ISO standards.

The rules permit some leeway in that they allow ‘sufficient time’ for the crew to complete any necessary fuel changeover operation as soon as possible after arrival at the berth and as late as possible before departure. Ships in port for period less than one hour of those that connect to shore electricity supplies are exempt from the requirement.

Considering the IMO timeline for sulphur levels, the EU is now only out of step in applying the 0.1% limit to ports outside of the two SECA zones.

Away from the EU, China’s Air Pollution Control (Marine Light Diesel) Regulation 01/04/2014 introduced a new sulphur content cap of 0.05% for the locally supplied marine light diesel (MLD). Hong Kong’s Environmental Protection Department has required all ocean-going vessels to use low sulphur fuel, defined in the new legislation as fuel with sulphur content not exceeding 0.5% by weight, when at berth in Hong Kong waters. All such ships must initiate fuel switch upon arrival at berth, complete the switch to low sulphur fuel within one hour, then use low sulphur fuel throughout the berthing period until one hour after departure.

On 4 December 2015, China announced the establishment of further ship ECAs in the Pearl River Delta, the Yangtze River Delta and the Bohai Bay rim area. The regulation applies to all merchant ships navigating, anchored or under operation in the waters of the control areas. With effect from 1 January 2016, ships were required to follow the requirements current international conventions or local laws/regulations (whichever is stricter) on the emission control of SOx, particulates and NOx. If the port condition allows, ports within control areas may implement stricter requirements than current conventions, regulations such as requiring use of fuel with 0.5% m/m Sulphur content or below.

The implementation schedule for the new Chinese requirements is:

  • From 1 January 2016, some ports (if the port condition allows) within the control areas may implement the requirement for use of fuel with 0.5% m/m sulphur content or below when ships are alongside or at anchor. Note that this is for any port within the control area, not just the key/core ports;
  • From 1 January 2017, key/core ports of control areas shall implement the requirements for use of fuel with 0.5% m/m sulphur content or below when ships are alongside or at anchor;
  • From 1 January 2018, all ports within control areas shall implement requirements for use of fuel with 0.5% m/m sulphur content or below when ships are alongside or at anchor; and
  • From 1 January 2019, ships entering into control areas shall use fuel with 0.5% m/m sulphur content or below.

It should be noted that following an assessment of the effects of the above actions China will possibly implement requirements for use of fuel with 0.1% m/m Sulphur content or below after 31 December 2019. The requirements for ships at berth or at anchor are applicable from one hour after ships are berthed to one hour before departure. Ships may use other alternative measures to reduce emissions, such as shore power, clean energy systems or scrubbers.