While these categories apply to refineries in general, a given refinery may have
aspects of more than one configuration as a result of history or market decisions.
Hence, the categories are not hard and fast.
The following discussion will describe each type of refinery and the implications
of the refinery configuration. More detailed discussion of economics can be found
in the chapter “▶ Petroleum Refinery Planning and Economics.”
Topping Refinery
A topping refinery is the simplest configuration. The refinery processing scheme
primarily consists of a crude unit making light ends (C 1 –C 4 ), naphtha, kerosene,
and some diesel. The atmospheric residue from the crude unit is normally sold as
fuel oil or an intermediate. The flowsheet for such a refinery is shown in Fig. 3.
Products from a topping refinery do not undergo much additional treatment.
Specifically, they do not undergo chemical processing to change their boiling range
(cracking, coking) or to improve the products’ characteristics (like reforming or
hydrotreating).
As a result of the limited process capabilities of this refinery, these facilities
are usually found in locations where environmental regulations are lax, where there
is a use for the intermediates, or at oil field processing facilities to stabilize the
crude.
One example of this type of facility has been in the Alaskan pipeline where
topping units are installed at pump stations to extract enough fuel from the crude to
power the pumping station. Some small refiners also top crude to recover the heavy
oil for asphalt production – this is where the definitions blur some.
Crude fed to a topping refinery is generally light, sweet material to get the most
value from the equipment. This limits crude options and flexibility.
The advantages of topping refineries lie in their simplicity and low cost. It is
relatively easy to operate a crude column. Compared to more complex refineries,
these are cheap to build, with flexibility in size.
The key disadvantages of topping are in the limited crude slate, products that
will not meet most environmental specifications and must be sold as intermediates,
Light Ends
To Fuel, Possible Butane Sales
SR Naphtha
To High S gasoline or Intermediate
Crude
SR Kerosene
To Jet or Intermediate
SR Diesel
To Offroad, Marine, or Intermediate
Atm Residuum To Fuel Oil or Asphalt
Atm
Crude
Unit
Fig. 3 Simple topping refinery flowsheet
Petroleum Products and a Refinery Configuration
83
aspects of more than one configuration as a result of history or market decisions.
Hence, the categories are not hard and fast.
The following discussion will describe each type of refinery and the implications
of the refinery configuration. More detailed discussion of economics can be found
in the chapter “▶ Petroleum Refinery Planning and Economics.”
Topping Refinery
A topping refinery is the simplest configuration. The refinery processing scheme
primarily consists of a crude unit making light ends (C 1 –C 4 ), naphtha, kerosene,
and some diesel. The atmospheric residue from the crude unit is normally sold as
fuel oil or an intermediate. The flowsheet for such a refinery is shown in Fig. 3.
Products from a topping refinery do not undergo much additional treatment.
Specifically, they do not undergo chemical processing to change their boiling range
(cracking, coking) or to improve the products’ characteristics (like reforming or
hydrotreating).
As a result of the limited process capabilities of this refinery, these facilities
are usually found in locations where environmental regulations are lax, where there
is a use for the intermediates, or at oil field processing facilities to stabilize the
crude.
One example of this type of facility has been in the Alaskan pipeline where
topping units are installed at pump stations to extract enough fuel from the crude to
power the pumping station. Some small refiners also top crude to recover the heavy
oil for asphalt production – this is where the definitions blur some.
Crude fed to a topping refinery is generally light, sweet material to get the most
value from the equipment. This limits crude options and flexibility.
The advantages of topping refineries lie in their simplicity and low cost. It is
relatively easy to operate a crude column. Compared to more complex refineries,
these are cheap to build, with flexibility in size.
The key disadvantages of topping are in the limited crude slate, products that
will not meet most environmental specifications and must be sold as intermediates,
Light Ends
To Fuel, Possible Butane Sales
SR Naphtha
To High S gasoline or Intermediate
Crude
SR Kerosene
To Jet or Intermediate
SR Diesel
To Offroad, Marine, or Intermediate
Atm Residuum To Fuel Oil or Asphalt
Atm
Crude
Unit
Fig. 3 Simple topping refinery flowsheet
Petroleum Products and a Refinery Configuration
83