The continued use of heavy fuel oil with an exhaust gas cleaning system (EGCS) is the most environmentally beneficial means of meeting global greenhouse gas (GHG) emissions targets, Chief Scientist Dr. Elizabeth Lindstad concluded in a study published by Norway’s SINTEF.
“Studies indicate that two-stroke engines with Exhaust Gas Recirculation (EGR) and scrubbers represent the most cost- and GHG-effective way of meeting both IMO Tier 3 NOx rules and the 2020 sulphur cap,” Dr. Lindstad said.
Dr. Lindstad stated that based on the energy consumed during the global production of distillate fuels, the continued use of residual fuel will have a positive impact on global GHG emissions, given the energy required to produce distillates would result in higher levels of CO2 being released into the atmosphere.
“With new modern refineries set up to convert crude into higher priced products, HSFO will, from 2020, be delivered from existing refineries where its share of energy consumption can be considered to be next to nothing. The explanation is that the heavy bunker oil coming out from the refinery is the bottom of the barrel. If we acknowledge the lower energy consumption in delivering HSFO and deduct the refining we get 9 to 10g of CO2 equivalent per MJ for HFO, rather than 13 to 15 of CO2 equivalent per MJ for LSFO/MGO.”
Dr. Lindstad also believes that emissions abatement rules need to be reviewed to consider pollution problems in different areas.
“To meet climate targets, i.e. reduce global GHG emissions, we can no longer afford to have standards that are strict in areas where we do not have local pollution problems, while areas with high pollution may need even stricter rules than today,” Dr. Lindstad told the Clean Shipping Alliance 2020 (CSA 2020).
Ian Adams, CSA 2020 Executive Director, noted that the industry has long realized that there was an energy penalty differential in the production of fuels.
“Using higher sulphur fuels with an exhaust gas cleaning system will have a beneficial impact on the global reduction of sulphur and nitrogen oxides emissions, and also on GHG emissions,” Adams concluded.