MARINE FUELS

INTRODUCTION

• Intermediate Fuel Oil (IFO) is a combination of Distillate and Residual Fuel.

• Distillate and residual fuels are blended into various combinations to derive

the different grades of marine fuel oil.

• In terms of cost, distillates are more expensive than intermediates, and

residual fuels are the least expensive.

• Distillates and/or residual fuel oil stocks are blended with blending

components or cutter stocks to achieve internationally accepted product

specifications provided by the 1987 (revised in 1996) international standard,

ISO 8217, that defines the requirements for fuel grades for use in marine diesel

engines.

TYPES OF MARINE FUELS

FUEL TYPE FUEL GRADE COLLOQUIAL INDUSTRY NAME

Distillate DMX, DMA, DMB, DMC MGO & MDO

IntermediateRME/F – 25 RMG/H – 35

Marine Diesel Fuel or Intermediate Fuel Oil (IFO 180, IFO 380, IFO 500 &

IFO 700)

ResidualRMA – RMH, RMK &

RMLFuel Oil or Residual Fuel Oil

BLENDING STOCKS

STRAIGHT RUN REFINERY

Produce Straight Run Stocks used in marine fuel blending.

Includes light diesel, heavy diesel and straight run residue.

COMPLEX REFINERY

Derive similar blending stock components as the output from FCC unit.

Includes light & heavy diesel as well as LCO & HCO. HCO also comes from residual output from visbreaker units.

These blending stocks are further mixed with existing product streams from a refinery to manufacture a variety of marine fuel grades.

MARINE GAS OIL

MGO LCO + Distillate Oil

Highest Marine Fuel grade

Expensive

Lighter fraction and better quality fuel.

For faster moving engines

MARINE DISTILLATE OIL

MDO KERO + LGO + DGO orDMC + Residual Fuel (10 – 15%)

DMA & DMB used in small to medium size vessels.

DMC is heavier fuel but sometimes called as intermediate fuel as it can be blended with residual fuel.

Expensive if compared to intermediate fuels.

INTERMEDIATE FUEL OIL

IFO RMG – 35 or IFO 380 the most commonly used grade.

Manufactured at refinery

Visbroken Residue + HCO + LCO

High sulfur content, i.e. 5%

RME – 25 or IFO 180 another well known grade.

Lower viscosity and metal content but the same sulfur content.