Heavy Fuel Oil

Basics

• Often Abbreviated as HFO
• A Category of Fuel Consisting of Viscous Tar-Like Hydrocarbons
• Also often called #6 Fuel Oil, Sixth Oil, or Bunker Oil/Bunker Fuel (This is derived from the concept of it’s use in shipping and the historical concept of a Coal Bunker , most Marine Fueling Operations are called “Bunkering” as well)
• Largely being phased out for Marine Diesel Oil and/or LNG
• Often tends to have a high sulfur content as well, although recent IMO Regulations and such have effected this
• Also related are the concepts of “Residuals” either from conventional Fractional Distillation or from the Vacuum Distillation Unit , HFO and Asphalt / Bitumen are the main products of the lowest fractions of these
• Due to it’s viscous nature, cleanup can be more challenging than other materials ( Oil Spill Adsorbents don’t wick it up as well)

Use

As a Fuel

• Storage is complicated by the high sulfur content, and viscosity issues
• More Frequent/Intense Tank Cleaning may be needed
• Tank Heater Coils and potentially even Insulated Tanks may be needed as compared to a conventional Atmospheric Storage Tank for Gasoline , Diesel Fuel , or Marine Diesel Oil
• Due to the complicated handling process, the fuel is typically reserved to Large Marine Vessels and Power Plants which can already handle the complexity and take advantage of the lower cost of the fuel itself
• Use for Process Heat via Direct Fired Heaters or in a Furnace etc is also a large use case (Although Natural Gas is far easier to run and in many cases cheaper)

As a Chemical Feedstock

• It can be Upgraded or “Cracked” to Lighter fractions via Thermal Cracking or via Fluid Catalytic Cracking and/or Hydrocracking
• It is also used in the Asphalt industry for Asphalt Concrete etc as an additive

OSE Context

• Given OSE currently doesn’t do much Refining this isn’t too big of a concern
• Pyrolysis of wood/biomass can create a Bio-Tar which can have comprable properties, if large volumes were collected, HFO would be a decent “industry standard” to work with
• If Pyrolysis-Oil / HTL Bio-Crude is investigated/ramped up, Vacuum Distillation Unit Residuals / Refinery Slops may become a large enough flow to warrant study+management

Internal Links

• Bitumen / Tar (Related Concepts)
• Mazut (The USSR/Russian Federation Standards/Name for this type of fuel)
• Refinery Slops / Slops Tank
  • While more related to PCW / FOG , to an extent Refinery Slops can be funneled into much of the same process such as Entrained Flow Gasification etc

External Links

• A RBN Energy Post Titled “ Yo Ho Ho And A Cargo Of Bunkers – The Gulf Coast Market For Fuel Oil”
  • Dives into Classifications a bit, need to check the Wikipedia page as well, but at the end of the day need to grab the proper ISO + IMO standards, and maybe supplement with ASTM/API ones