Low sulfur fuel

The European Union (EU) directive 2005/33/EC, which came into force January 2010, requires ships to burn fuel with better than 0.1% sulfur by mass, at berth in EU ports.

This requirement does not distinguish between steam ships or motor ships. To comply with this requirement Shell undertook a study on the impact of low sulfur (LS) marine gas oil (MGO) in marine boilers for their LNG carriers. The writeup on this study was published in Marine Engineers Review (MER) March 2010.

This article should be of interest to Canadian and US regulators, as well as the Great Lakes fleet operators, in their discussions on the implementation of an environmental control area (ECA) for the Great Lakes.

Shell found that LSMGO can be burnt in marine boilers, but it requires some system changes. Traditionally boilers are fired by heavy fuel oil (HFO) which must be heated, on the other hand LSMGO must be cold to avoid gassing in the supply line. Compared to HFO, LSMGO has a 6% higher calorific value, poorer lubrication characteristics and a 10% shorter flame length, etc. In closing the article states that their "study of the use of LSMGO in main and auxiliary engines resulted in a proposal for modification of vessel equipment and operations to enable the safe and robust changeover to LSMGO fuel". Stating that the low viscosity and lubrication characteristics are a concern for some rotating equipment in marine engines.

What the article suggests is that the exemption of US flagged steamers from LS fuel requirements and the economic hardship exemptions for motor ships, as contemplated by the US regulator is based on economics and disregards the reason why the USA and Canada petitioned IMO for the ECA designation.