Alternative fuels: Options, availability and regulations of cleaner fuels

The marine shipping industry has been facing challenges to reduce engine exhaust emissions and greenhouse gases (GHGs) — in particular, carbon dioxide (CO2) from their ships. That is because international regulatory bodies such as the International Maritime Organization (IMO) and national environmental agencies of many countries have issued rules and regulations that drastically reduce GHG and emissions emanating from marine sources.

Indeed, at the moment, the majority of ships run on a combination of heavy fuel oil (HFO) and marine diesel oil (MDO). However, recent factors – like new sulfur limits and fuel efficiency regulations – have given ship owners a strong incentive to look for more environment-friendly fuel options.

Fortunately, there are many viable alternative fuel options which are becoming increasingly available to ship operators. These include LNG (liquefied natural gas) and hybrid fuels containing a blend of biofuels, methanol and ethane. Read on to find out more about these alternative fuels, and their advantages and disadvantages when it comes to the shipping industry

Alternative fuels in shipping:

There are two main available options of alternative fuels for shipping:

1-      Biofuels:

Biofuels are alternative fuels that include bio-oil; renewable diesel made from wood waste or fats such as used cooking oil; as well as mixtures of these biobased feedstocks with petroleum-based feedstocks including petroleum, natural gas and coal.

Liquid biofuels that are available for marine use today are:

–          Biodiesel

–          Fatty acid methyl ester (FAME)

–          Algae fuels

–          Methanol

–          Hydrogenation‐derived renewable diesel (HDRD) also known as second‐generation biodiesel

–          Pyrolysis oil.

2-      Gaseous Fuels:

Gaseous fuels are another option but require a different type of fuel handling system, fuel tanks and gas burning engines that are not currently in use on most ships.

The gaseous fuels that are available for marine use are:

–          Natural gas (CNG or LNG)*

–          Propane (liquid propane gas or LPG).

*Note: Natural gas can be carried as a compressed fuel called compressed natural gas (CNG) or in a liquid state called liquefied natural gas (LNG).

Advantages and disadvantages of alternative fuels.

The alternative fuels industry has grown dramatically for alternative fuels, and all of them have various advantages and disadvantages from the standpoint of the shipping industry. It is hard to assess their impact and availability just yet, given that implementation of these fuels has begun only years ago. However, we can still draw some clear perks and problems about the most used alternative fuels.

1- When it comes to biofuels, the advantages are clear, as its use reduces emanations of toxic chemicals like sulfur and CO2 drastically. However, unfortunately it costs more than regular diesel fuel which can be a big obstacle for many shipowners. Moreover, biofuels can be corrosive to rubber engine parts, and thickens greatly in cold temperatures, which makes it burn poorly under cold conditions.

2- For ethanol, a major plus is that it can be synthesized and does not need to be drawn from the ground or imported. On the other hand, ethanol procures less energy per unit volume, which can be a problem for longer trips.

3- As for compressed natural gas, it has been established that its usage significantly reduces emission of toxic gases such as carbon monoxide and nitrogen oxides. CNG is plentiful, burns more cleanly than gasoline, contributes to engine efficiency and does not pose a significant health hazard if accidentally spilled. CNG does however have several disadvantages, including increased costs of purchasing a vehicle that runs on CNG and more frequent stops are needed for refueling those vehicles.

In conclusion, it is an inevitable fact that the shipping industry is relying more and more on alternative fuels, driven by the firm regulations set by the relevant authorities to protect our environment. There are fortunately many alternative fuel options, and each ship owner has to find the best solution for their ships. The industry is sure to move forward towards its sustainability goals with these positive changes.