Tuesday, June 11, 2013




Short term:
-          Reduced fuel sulfur level in SO2 Emission Control Areas (SECAs) from 1.5% to 0.5%.
-          Include SO2 /PM related health effects in addition to impacts on air, sea, and land as justification for SECA.
-          Enhance SECA program to high ship-traffic areas in Mediterranean, North Atlantic and Pacific Rim.
-          Regional limits in coastal places, inland channels and at ports.
Medium term:
0.5% sulfur fuel worlwide

Long term:
Synchronization with on-road diesel fuels (500 ppm to 10-15 ppm, in the long-term)
-          International requirements (IMO)

New engines

Short term:
-          NO2 standards 40% percent below present IMO standards (Year 2000 level).
-          PM levels
-          Encourage new technology developments

Medium term:
-          NO2 standards 95% percent below present IMO standards (Year 2000 level)
-          PM levels further cut down
-          Encourage new technology developments

Long term:
Encourage the application of advanced systems, particularly near-zero emission technologies in potential applications.
-          International standards (IMO)

New vessels

Short term:
-          Adopt global requirements for on-land power standardization.
-          All newly-built ships with onshore electricity capability, particularly ferries and cruise ship.

Long term: Promote the utilization of modern ship-design principles for potentially efficient applications
-          Promoting contracting of cleanest carriers.
-          Environmentally sensitive fees and charges.
-          International standards (IMO).

Existing vessels and engines

Short term:
-          Apply emissions operating standards by ship class and engine properties depending on observed retrofit potential.
-          Study viability and potential benefits of programs to promote early vessel retirement and environmentally-viable decommissioning.
-          International levels (IMO)
-          Promoting contracting of cleanest carriers
-          Environmentally sensitive fees and charges.

At port

Short term:
Select strategy that provides benefits for optimum reduction of emissions, based on local fuel availability and environmental application of electricity power generation
-          Onshore electricity
-          Least sulfur on-road fuel and NO2 and PM post-treatment.

Medium term: Market-based approaches to promote low- or non-carbon fuel sources to service onshore electricity for berthed vessels
-          Port authorization needed.
-          Promoting contracting of cleanest carriers.
-          Environmentally sensitive fees and charges.

Short term:
-          Implement inventory of GHG emission and fleet baseline
-          Market-based methods for ships.
-          Implement fuel economy requirements by ship type and engine properties for new vessels.

Medium term:
Implement fuel economy requirements by vessel type and engine class for existing ships.
-          Promoting contracting of cleanest carriers
-          Environmentally sensitive fees and charges.
-          Cap and trade program for maritime industry alone.

-          International requirements (IMO).

Assessment of potential reduction of emissions

Assessment of potential reduction of emissions

Potential for reduction of CO2 emissions
5.76 Several options for efficiency improvements have been considered in earlier paragraphs. The potential for energy saving by combining these steps is very vital.

Nevertheless, costs, lack of incentives and other obstacles block many of them from being implemented. Hence, when assessing the potential savings, we also establish clear assumptions regarding the extent of compromise, effort and extra costs that are needed.

An evaluation of potentials for saving energy using present technology and methods is presented in table 5-2. The values given in this table exhibit the variations in benefits for various ship types and the level of motivation to achieve savings.

5.77 Projected efficiency improvements are presented as scenarios in Chapter 7. The high values presented in table 5-2 relate fairly well to the scenario with the highest improvement in energy consumption, in which net improvements, without the use of low-carbon fuels, range from 58% to 75% in 2050, depending on the type ship. This assumption, including indicators of historical transport efficiency for various ship types, is portrayed in figure 5-1. The historical background for the generation of efficiency data is shown in Chapter 9.

Renewable energy from shore

Renewable energy from shore
5.45 Renewable energy is generated on land using wind generators, hydroelectric plants, geothermal plants, solar-energy plants, etc. Potentially, power from such providers could be harnessed to run ships if a suitable energy carrier was available. However, as long as there is a shortfall of renewable power onshore, there is little prospect for using land-based renewable energy to propel ships. A noteworthy exception is the use of land-generated power while a ship is berthed.
15. Ideally, fuel cells, solar-power, wind kites, etc. are all potential alternative technologies; but they are often seen as auxiliary power sources and not viable replacements for the main propulsion systems on a ship.

14. Other fuel sources may also play a role and bio-fuels can be utilized in operating ships. However, with the amount of fuel used by the maritime industry and the present economic instability, the industry would deem it wise for lawmakers to investigate more clearly the impact of a significant take-up of bio-fuels by such a big consumer as global shipping before arriving at any decisions.
5.2 Present propulsion systems using carbon-based fuels are seen as the only realistic large volume fuel for vessels over the next two decades years and even longer.

Use of natural gas is presently leading in terms of a lower carbon fuel for the short-medium term, either as compressed natural gas (CNG) or liquefied natural gas (LNG). With existing available propulsion equipment, its use could attain around 20% reduction in CO2 emissions in comparison to residual or diesel-oil fuels.
5.3 Ultimately, hydrogen could become a viable source. Sustainable bio-fuel may also have a role to play if enough fuel were provided to shipping. Alternatively, new and radical fuels and/or technologies may play a vital role.

Fuels with lower fuel-cycle CO2 emissions
5.46 Emissions of CO2 can be reduced by using fuels with lesser overall emissions through the full-fuel process (i.e., production, refining, distribution and consumption). The conversion from residual fuels to distillate fuels, implied by the sulphur regulation in the revised MARPOL Annex VI, has already been accepted; hence, there is no point considering the potential benefits and disadvantages of this move on the emission of CO2 now. Other fuel alternatives with bright prospects for cutting the production of CO2 include bio-fuels and natural gas.

5.47 Current-day bio-fuels (also known as “first-generation” bio-fuels) come from sugar, starch, vegetable oil, or animal fats. Many of these fuels can be readily used for ship diesels with no (or minor) alteration of the engine. Bio-fuels can be upgraded (hydrogenated) in a refinery. As such, the end-result is of high-quality and the practical problems mentioned do not apply. This upgrade process requires energy and leads to additional emissions.
5.48 The net benefits on emissions of CO2 vary among many types of bio-fuels. Not all bio-fuels provide a CO2 benefit. Bio-fuels, in fact, have in certain instances led to a 7% to 10% increase in the NO2 emissions.
5.51 In summary, the current potential for cutting COemissions from ships by using bio-fuels is inadequate. This is not only because of technology issues but also of cost, of limited availability and of other factors based on the production of bio-fuels and their use. Moreover, the bio-fuels are significantly more costly today than petroleum fuels.

Liquefied natural gas (LNG)
5.52 Liquefied natural gas is an alternative fuel in the maritime industry. Having a higher hydrogen-to-carbon ratio compared with oil-based fuels, this fuel produces lower specific CO2 emissions (kg of CO2/kg of fuel). Moreover, LNG is a clean fuel since it contains no sulphur; this eliminates the SOx emissions and almost eliminates the emissions of particulate matter.

Furthermore, the NO2 emissions are cut by up to 90% due to decreased peak temperatures in the process of combustion. Unfortunately, LNG use will increase methane (CH4) emissions, thus cutting the net global warming benefit to 15% instead of 25%.
5.54 One of the primary obstacles for LNG use as a fuel for vessels is finding sufficient space for onboard fuel storage. Energy content being held equal, LNG is 1.8-times larger than diesel oil in terms of volume. Nevertheless, the large pressure storage tank needs ample space, and the final volume requirement reaches to three times that of diesel oil.
Shifting from diesel propulsion to LNG propulsion is possible, but LNG is mostly applicable for new ship construction since significant alteration of engines and allocation of addition storage capacity is needed.
5.56 In summary, the current potential for cutting emissions of CO2 from vessels through LNG use is relatively small, since it is generally suited for newly-built ships and because  LNG bunkering choices are limited today.

The cost of LNG is currently substantially lower than the cost of distillate fuels, justifying an economic incentive to shift to LNG.

As to alternative fuels, only LNG is a viable competitor for replacing conventional fuels. The problematic issue of on-vessel storage and containment systems and the land-based infrastructure needed for resupply adversely limits the option for this fuel. The operational distance of ships utilizing LNG is constrained by the fuel storage size and boil-off standards. LNG is seen by industry as more fitted to short sea-navigation than the deep ocean trade. In fact, several ferry routes with dedicated land-based supply infrastructure in Scandinavia presently use LNG as fuel for main propulsion.

The shipping industry is a multi-service industry, and provides many various functions for society.

Nuclear energy is technically viable for sea vessels with many instance of nuclear-powered commercial and military ships. Safety and acceptability issues are, naturally, predominant in this ongoing debate. Nuclear powered ships require a delicate infrastructure and disaster response scheme. Due to common apprehensions among countries, nuclear propulsion will not play an important role in commercial vessels. Nuclear power, though put to effective use in the 1960s, would not be viable commercially or acceptable socially. If it were to be considered at all, it would be more acceptably and efficiently used for synthesizing marine fuels on land.

According to a research that IMO commissioned, technologies could cut fuel use and oil consumption by as much as “30–40%”. However, some of these approaches have been applied by merchants and the fall below their expectations.

Non-conventional technologies presently being evaluated for application, for instance, the sky-sail concept, twin-propeller and the under-hull air cushion give serious prospects.

The kite-system developer believes that the system may cut a ship‘s fuel consumption by an average of 10–35% annually, based on wind power availability. However, new tests have shown  a low passing grade for this system. Within ideal wind conditions, fuel usage can be cut temporarily by up to 50%. (528.pdf)

Emission-reduction technologies
5.57 Although COremoved by chemical conversion from flue gases, it is not deemed viable. Emission-cutting methods are generally applicable to pollutants within exhaust gases, NO2, SO2, PM, CH4 and NMVOC.

Emission-reduction options for NO2
5.58 NO2 emissions from diesel engines can be cut by using certain measures, such as:
- Fuel conversion.
- Modification of the combustion process.
- Modification of the charge air.
- Exhaust gas treatment (selective catalytic reduction, SCR).
5.59 A fuel’s sulphur content and its deposit-producing tendency can affect the possibilities for other emission-cutting technologies, such as exhaust-gas recirculation (EGR) or selective catalytic reduction (SCR). Usage and quality of water are problems met by options utiizing water.
5.61 LNG fuel usage is both a fuel switch and a combustion-process shift.
5.62 Reduction of NO2 by 15-20% from the present levels can be attained with changes in the internal-combustion process. Currently, cutting NO2 emissions to Tier III limits (~80% reduction) can only be reached by using selective catalytic reduction (SCR) post-treatment or LNG and lean, premixed combustion.

Emission-reduction options for SO2
5.65 Exhaust-gas scrubbing systems can be utilized to cut sulphur dioxide (SO2) levels. Two primary principles apply here: open-loop seawater scrubbers and closed-loop scrubbers. Both scrubber systems may also remove PM and reduce amounts of NO2.
Scrubbing of exhaust gases utilizes energy which is calculated in the range of 1-2% of the MCR.
5.66 Removal of SOthrough scrubbing reduces the exhaust gas temperature. On the other option, SCR technology needs high temperatures of exhaust gas and also produces low sulphur and PM content. Combining SCR with scrubbing to remove SO2 does not seem viable.
5.67 Polluting substances coming from the exhaust is carried by the wash-water.

Sulphur oxides react with seawater to produce stable compounds that are generally common in seawater and not considered dangerous to the environment in many places. However, particulates in the exhaust that are eventually disposed into the seawater may harm the environment. The revised IMO Scrubber Guidelines [31] establish limits for the effluent, including limits for Polycyclic Aromatic Hydrocarbons (PAH), pH, nitrates, turbidity and other materials. Port State standards for effluent pollutants will have a substantial impact on the possible use of seawater scrubbers. To achieve these standards, an effluent-treatment system must be installed. Normally, the more SO2 and PM removed by the scrubber from the exhaust, the more pollutants will need to be removed from the effluent.

Emission-reduction options for PM
5.70 Some PM emissions from fuels high in sulphur content can be cut by scrubbing with seawater. The potential reduction of PM levels are said to be from 90% to 20%, depending on the source. With low-sulphur fuels, PM emissions can be cut significantly by optimizing combustion to attain greater oxidation of soot and of PM, reducing the use of lube oil and certain additives in lube oil. Burning emulsions of fuel and water can also reduce PM emissions to a certain level.

Emission-reduction options for CH4 and NMVOC
5.72 Engine-exhausts containing methane (CH4) and non-methane volatile organic compounds (NMVOC) are relatively low. Limited reductions may be attained by optimizing the process of combustion. NMVOC can also be oxidized using a catalyst. These catalysts are commonly used in connection with SCR systems, where they oxidize unused ammonia and removing ammonia emissions.
5.73 CH4 emissions can be cut substantially through meticulous design to prevent crevices. However, a little CH4 emission is inevitable. Using a catalyst, this CH4 can be oxidized, although this is not as straightforward as cutting NMVOC levels. Further research and development are required in this area.
5.74 Emissions of CH4 from gas-powered engines can be practically removed through high-pressure gas injection instead of lean premixed-combustion. This alternative principle is believed to be well suited for big two-stroke engines. The disadvantage, however, is that NO2 emission reduction through direct injection is lower than what can be attained with the lean premixed-combustion option.

Alternatives for reducing HFC emissions and other refrigerants

5.75 Hydrofluorocarbons (HFC) emissions are connection to leaks during the operation and maintenance of refrigeration systems. Technical steps to cut down leaks include designs less affected by corrosion, vibration and other stresses, decreasing the effect of leaks by cutting down the refrigerant charge (i.e., by cooling indirectly) and compartmentalizing the piping design in order to isolate a leakage.

Wind and sun

Wind and sun:

Renewable energy sources
5.39 Renewable energy can be utilized directly on board ships (by using solar, wave and wind energy) or energy can be generated on-land and converted and stored in an energy carrier to produce energy, such as electricity from batteries.

Wind power, onboard use
5.40 Wind power can be harnessed in many ways and used as the motive power for ships, for example by:
.1 Conventional sails;
.2 Solid wing sails;
.3 Kites; and
.4 Flettner-type rotors.
5.41 These systems have varying properties. Wind conditions vary depending on location; hence, certain regions have greater potential for wind power use and as routes than others. This study showed that the potential for wind energy was better in the North Atlantic and North Pacific than in the South Pacific. Fuel reductions were slightly higher at faster speeds.
However, in terms of percentages, the fuel savings were higher at lower speeds, due to the reduced total demand for propulsion power. In percentage terms, savings were typically about 5% at 15 knots, increasing to about 20% at 10 knots.
5.42 Present-day exposure to these technologies on board large vessels is limited, and modelling data are, therefore, hard to confirm. However, wind-assisted energy appears to have good prospects for saving fuel in the short and long run.
5.4 Solar and wind energy could also add to reduced CO2 emissions; but as a auxiliary source of energy rather than a single source. Propulsion using nuclear energy has been effectively operated in navy ships.

Solar power, onboard use
5.43 Present solar-cell technology is enough to address a mere portion of the auxiliary energy needs of a tanker, even though the whole deck space were installed with photovoltaic cells.

Obviously, during certain periods and in certain places, solar energy will be more than sufficient and the auxiliary power requirements could be supplied. Furthermore, since solar energy is not continuously available (e.g., at night), backup supply would be required. Hence, solar power seems to be of interest generally as a supplementary source of energy. With available technology, only a small percentage of savings on the total energy requirements can be realized, even with wide use of solar energy.

Moreover, currents price levels and efficiency put solar energy within the bottom end of the cost-effectiveness list [9].

Wave power, onboard use

5.44 This involves concepts for harnessing wave energy and/or vessel motion. For instance, gyro-based internal systems and wavefoils for external systems, stern flaps or relative motion between multiple hulled-vessels (such as trimarans) can augment a vessel’s power needs. These systems are highly complex and technical, not highly energy-efficient and are not considered potential sources of auxiliary energy.

Energy saving by operations

Fleet management, logistics and incentives

5.22 Energy efficiency can be enhanced by utilizing the appropriate ships in a transport system.Generally speaking, efficiency improves when we concentrate cargoes in larger ships as much as possible. Obviously, larger ships that are not fully loaded are not efficient when they do sail. Smaller ships, on the other hand, end up having higher net energy efficiency for being able to fill their cargo hold to capacity and having access to more ports and cargo types, [7].

5.23 Reductions in scheduled speed (i.e., accepting longer voyage periods) will enhance efficiency although it will result in more ships being required. Nevertheless, there is a trade-off between freight rates and fuel cost: with lower freight rates and higher fuel prices, it may be more advantageous to reduce speed.

Voyage optimization

5.29 Voyage optimization can be achieved by:

.1 choosing optimal routes to avoid adverse weather and current conditions will minimize energy consumption (weather routeing);
.3 ballast optimization – preventing unnecessary ballast use. Attaining optimal ballast may sometimes be difficult since it also affects the safety and comfort of the crew; and
.4 trim optimization – determining and operating at the proper trim.

5.31 Weather routeing can bring substantial savings for ships on particular navigational courses. Certain types of weather routeing systems, performance monitoring systems and technical support systems and other procedures can be used to help attain optimal voyage performance.

Energy management

There are certain cargoes, such as special crude oils, bitumen, heavy fuel oils, etc., that need heating.

The heat required may partly be provided by producing steam or using exhaust heat. However, in many instances an extra steam boiler is required to supply enough steam. Steam from exhaust gas is usually sufficient to heat the heavy fuel oil used on most vessels; in port, however, steam from an auxiliary boiler may be required.

5.35 It is often feasible to decrease energy use on board by achieving more conscious and optimal operation of ship systems. Examples of measures to under taken include:
.1 avoiding unnecessary use of energy;
.2 avoiding parallel running of electrical generators;
.3 optimizing steam plants (tankers);
.4 optimizing the fuel clarifier/separator;
.5 optimizing HVAC operation on board;
.6 cleaning heat exchangers and the economiser; and
.7 detecting and repairing leakages in boilers and compressed-air systems, etc.

A lot of savings may be achieved by upgrading automation and process control, for example, automatic temperature control, flow control (automatic speed control of pumps and fans) and automatic lights. The potential for attaining energy-savings using energy-management measures is hard to determine, since that depends on the ship’s previous operational efficiency and on the contribution of auxiliary power use in the overall energy scheme. A 10% savings on auxiliary power may be a practical target for many vessels. This amounts to about 1 to 2% of the total fuel consumption, depending on actual conditions.

5.37 Optimal maintenance and tuning up of main engines.
5.38 Maintaining a clean hull and propeller is vital in achieving fuel efficiency.

Selecting more effective hull coatings.

16. Reducing navigational for ships is often seen as a “quick win” in terms of reducing carbon emissions from vessels.

Recent studies reveal that many abatement technologies are available, and cost-effective, such as:

-          Slide valves reduce NO2 on slow-speed engines by 20%, very inexpensive, fit easily and are cost-effective.
-          In-engine controls could reduce new engine NO2 by 30%.
-          Selective Catalytic Reduction cuts NO2 by 90%.
-          Water Injection/Humid Air Motor cuts NO2 by 50%/75%.
-          Scrubbing by sea-water cuts SO2 by 75%.

Reducing the emission of GHG (Engineering)

Reducing the emission of GHG (Engineering)

Depending on which organization we are talking about, there are varying technical and operational procedures required to reduce the emission of GHG. The International Council on Clean Transportation released a long list of recommendations that would reduce the GHG emission (Appendix I), while IMO through the Marine Environment Protection Committee (MEPC) identified different classifications for the same purpose.

On April 9, 2009, the MEPC released its second IMO GHG Study. In the study, MEPC identified four categories of options to reduce ships emissions, namely:

·         Improving energy efficiency, that is, burning less fuel to attain the same output by optimizing the design and operation.

·         Exploring renewable energy sources (sun and wind).

·         Using emission-reduction technologies (chemical conversion, capture and storage)

·         Using fuels that produce less emissions (natural gas and bio-fuels)

Improving energy efficiency through boiler design and operation

Optimizing ship design

The design technology is categorized as short to medium term; it has to be inputted during construction of new ships. However, some of these optimization steps can be applied to existing ships. Each new vessel’s design specifications, such as ship’s size and the targeted speed, are considered the main hurdle toward achieving the optimal energy efficiency for the ship. Furthermore, some ports and rivers may impose limitations on the ship’s draught which further reduces its efficiency.

Optimizing the hull and superstructure

Even if the ship’s hull and its superstructure may cause minimal resistance, there still exist areas for more optimization for attaining higher efficiency. Design optimization on the hull and superstructure minimizes air resistance and drifting, especially for large container ships which have huge superstructures. The latest technology to reduce the hull’s frictional surface resistance is through the use of the air-bubble system which involves blowing air bubbles underneath the ship’s hull, thus improving fuel-use efficiency.

Optimizing the Power systems

This technology requires recycling the energy from the exhaust system through the use of power turbines. This energy can be utilized to drive a motor to generate electricity and also to support the main engine. The recovered energy can augment 10% to the total power. Likewise, Diesel-electric propulsion systems allow design flexibility that will result in energy saving.

Optimizing the propulsion systems

Increase in the propulsion power by using propeller vanes, contra-rotating propellers and ducts can significantly improve the energy efficiency. In like manner, using high-efficiency and asymmetric rudders can help optimize propulsion.

Operational efficiencies

Operational improvements, such as enhanced weather routing, optimized trim and ballasting, better main and auxiliary engine maintenance and tuning, hull and propeller cleaning, speeding up ship unloading and slower steaming, can significantly affect the ship’s emissions. The IMO has estimated that a speed reduction of merely 10% across the global fleet by 2010 would result in more than 23% decrease in emissions.