Alternative Fuels used for Shipping
Alternative Fuels used as fuel in shipping is not very wide spread currently but LNG (mainly sea going vessels) and vessels using electric drive with batteries or hydrogen (fuel cells) as energy storage (in small vessel applications and in ferries) are gaining attention. Also, several “drop-in” Alternative Fuels have been applied for shipping on an experimental basis.
Alternative Fuels for Shipping which will be reported on the EAFO portal are: Liquefied natural gas (LNG), Electricity (energy carrier), Hydrogen, Biofuels, Methanol, Dimethyl ether (DME), LPG. Most of the reporting in EAFO will be on demonstration projects using Alternative Fuels in Shipping and technology developments.
For sea going vessels, LNG is the most used alternative fuel. Concerning geographic scope, for sea going ships a global approach will be followed with more detail if available for the European operating area. For LNG, a traditional use is LNG carriers where most carriers use dual fuel diesel engines capable of using any combination of LNG and bunker fuels, using the LNG cargo boil off for fuel. Other sea going vessel types are already operational as well. Application of alternative fuels for inland shipping is limited and mainly aimed at trials.
LNG is also an attractive fuel option for vessels in particular to meet the new limits for Sulphur content in marine fuels decreasing from 1 % to 0.1 % from 1 January 2015 in Sulphur Emission Control Areas (SECAs) in the Baltic Sea, North Sea and English Channel as set by the International Maritime Organisation (IMO)19. These obligations will be relevant for about half of the 10,000 ships currently engaged in intra-EU shipping. LNG is an attractive economic alternative also for shipping outside SECAs, where Sulphur limits will decrease from 3.5% to 0.5% from 1 January 2020, and globally.
The use of alternative fuels is regarded today as a key relevant area of technological development for sustainable transport. In shipping, like in other transport modes, there is today a consistent focus given to the potential application of different cleaner fuel solutions, with some of them posing significant challenges to ship design. The gradual adoption of these fuels, and the example set by first movers has been fundamental in paving the way to a wider use of alternative fuels for the future.
Taking into account the large share contribution of shipping to the in the worldwide transport market (accounting for over 80% of world trade by volume, 3% of global greenhouse gas emissions and contributing to air pollution close to coastal areas and ports), the gradual adoption of alternative fuels by shipping would have a significant positive immediate environmental impact.
One common challenge, however, posed by the adoption of most alternative fuels are their physico-chemical characteristics, typically with associated low flashpoints, higher volatilities, different energy content per unit mass and, in some cases, even toxicity. The adoption and entry into force of the draft International Code of Safety for Ships using Gases or other Low flashpoint Fuels (IGF Code), along with proposed amendments to make the Code mandatory under SOLAS, by MSC95, on 11 June 2015, was a decisive step forward in addressing those challenges, at the regulatory level. The IGF Code includes mandatory provisions for the arrangement, installation, control and monitoring of machinery, equipment and systems using low flashpoint fuels, such as liquefied natural gas (LNG), to minimize the risk to the ship, its crew and the environment, having regard to the nature of the fuels involved. LNG has been the first focus of the IGF Code; however provisions for Methyl/Ethyl alcohols, Fuels Cells and Low Flashpoint Oil Fuels are being drafted for the expected first revision of the code, in 2020/21.
There is a long list of fuels or energy carriers that can be used in shipping. The ones most commonly considered today are Liquefied Natural Gas (LNG), Electricity, Biodiesel, and Methanol. Other fuels that could play a role in the future are Liquefied Petroleum Gas (LPG), Ethanol, Dimethyl Ether (DME), Biogas, Synthetic Fuels, Hydrogen (particularly for use in fuel cells), and Nuclear fuel. All these fuels are virtually sulphur free, and can be used for compliance with sulphur content regulations. They can be used either in combination with conventional, oil-based marine fuels, thus covering only part of a vessel’s energy demand, or to completely replace conventional fuels. The type of alternative fuel selected and the proportion of conventional fuel substituted will have a direct impact on the vessel’s emissions, including GHG, NOx, and SOx.
Being international in its operation and organization, the maritime sector is regulated by the International Maritime Organization (IMO) under the UN. IMO handles issues regarding safety, security and pollution associated with international shipping. A major issue of pollution from shipping are the particles emitted due to the high levels of sulphur in the fuels. The IMO has put forward strict regulation of the fuel sulphur levels. Emission Control Areas (ECAs) have been set up in coastal waters in Europe, North America, and Asia. Within these areas only 0.1% low- sulphur fuels are allowed, and from 2020 ships sailing in non-ECA areas will need to use less than 0.5% sulphur in their fuel. If low sulphur fuels are not used, scrubbers needs to be installed in order to remove the SOx emissions.
These regulations means that an estimated 70% of the fuels currently used by the sector needs to be modified or changed. Greenhouse gas emissions, i.e. CO2 are currently not regulated, but expectations are that regulation of CO2 emissions will be implemented in the short to medium term.
The sector is currently looking at solving the issue of reducing sulphur levels by using more refined fuels, an operation done at the oil refinery. This will not only add an extra cost, but it will also increase the CO2 emissions associated with the fuel as more refining will be required. The low sulphur fuels currently introduced are labelled Very low Sulphur Fuel Oil (VLSFO) having between 0.1 to 0.5% sulphur and Ultralow Sulphur Fuel Oil (ULSFO) having below 0.1% sulphur content. Another solution to reduced sulphur emissions is to use liquefied natural gas (LNG) as fuel, but this requires a refitting of the engines, just as pressurized fuel storage needs to be installed onboard. Other fuels such as methanol are used to a smaller degree with the latest generation of diesel engine technology, but are still at a supply infrastructure premature state.
Biofuels have very low sulphur levels and low CO2 emissions, as such they are a technically viable solution to low-sulphur fuels meeting either the VLSFO or ULSFO requirements. The immediate challenge is that the shipping sector has little knowledge on handling and applying biofuels as part of their fuel supply. Another challenge is that the volumes of biofuels required to supply the shipping sector are large. A single very large ship may consume the annual production from a single medium sized biofuel facility e.g. 100 mio. liters. The market entry for biofuels in the marine sector is therefore most favorable onboard smaller vessels for coastal waters or for use as auxiliary ultra-low sulphur fuel in ports. Of the current biofuels commercially available, only plant biodiesel derived from plant oil or pulping residues and bioethanol are produced at a level where they can supply significant volumes of fuel. The current renewable diesel type fuels are mainly produced from plant based oils or products thereof e.g. used cooking oil (UCO), and the potential supply of sustainable renewable diesel with the current technology is an estimated 10-20 Mt. Another issue is that the plant oil based fuels are the main fuel type currently used at a significant scale for bio jet fuels, leading to competition for feedstocks between the shipping and aviation sectors.
Sources: DG MOVE, EMSA, IEA Bioenergy