Abstract
The “light ends” unit is the only process in a refinery configuration that is
designed to separate “almost” pure components from the crude oil. Its growth
initially resulted from the need of those components such as butanes and propanes to satisfy a market of portable cooking fuel and industrial fuels. The need
for modern gasolines has added to the demand for light ends to make high-octane
blending components. This chapter describes the process and design of units to
separate the light ends into useful products or into cuts for further processing in
the refinery. An example design is provided.
Keywords
Light ends • Butane • Propane • LPG • Refinery
Introduction
The “light ends” unit is the only process in a refinery configuration that is designed
to separate “almost” pure components from the crude oil. Its particular growth has
resulted from the need for those components such as butanes and propanes to satisfy
a market of portable cooking fuel and industrial fuels. That these products can be
suitably compressed and stored in small, easily handled containers at ambient
temperatures provided the market popularity for these products, suitably titled
butane LPG and propane LPG. The term LPG refers to liquefied petroleum gas.
The introduction of “no lead” gasoline in the late 1960s established the need of
octane sources additional to the aromatics provided by high severity catalytic
reforming. A source of such high-octane additives is found in some isomers of
butane and pentane. This added to the need for light ends processes which in many
cases included the separation of isobutanes from the butane stream and also
isopentanes from the light naphtha stream.
A Process Description of a “Light End” Unit
The “light ends” of crude oil are considered to be those fractions in the crude that
have a boiling point below cyclohexane. The “light ends” distillation units however
include the light naphtha cut separation, which is predominately pentanes and
cyclopentanes, from heavy naphtha which contains the hexanes and heavier hydrocarbons necessary for the catalytic reformer feed. The feed to the “light ends”
distillation process is usually the full range naphtha distillate from the atmospheric
crude distillation unit overhead condensate drum. In many cases the distillates from
stabilizing cracker and reformer products are added to the crude unit overhead
distillate to be included in the “light ends” unit feed.
A typical process configuration for this unit is given in the flow diagram (Fig. 1).
200
D.S.J. Jones
The “light ends” unit is the only process in a refinery configuration that is
designed to separate “almost” pure components from the crude oil. Its growth
initially resulted from the need of those components such as butanes and propanes to satisfy a market of portable cooking fuel and industrial fuels. The need
for modern gasolines has added to the demand for light ends to make high-octane
blending components. This chapter describes the process and design of units to
separate the light ends into useful products or into cuts for further processing in
the refinery. An example design is provided.
Keywords
Light ends • Butane • Propane • LPG • Refinery
Introduction
The “light ends” unit is the only process in a refinery configuration that is designed
to separate “almost” pure components from the crude oil. Its particular growth has
resulted from the need for those components such as butanes and propanes to satisfy
a market of portable cooking fuel and industrial fuels. That these products can be
suitably compressed and stored in small, easily handled containers at ambient
temperatures provided the market popularity for these products, suitably titled
butane LPG and propane LPG. The term LPG refers to liquefied petroleum gas.
The introduction of “no lead” gasoline in the late 1960s established the need of
octane sources additional to the aromatics provided by high severity catalytic
reforming. A source of such high-octane additives is found in some isomers of
butane and pentane. This added to the need for light ends processes which in many
cases included the separation of isobutanes from the butane stream and also
isopentanes from the light naphtha stream.
A Process Description of a “Light End” Unit
The “light ends” of crude oil are considered to be those fractions in the crude that
have a boiling point below cyclohexane. The “light ends” distillation units however
include the light naphtha cut separation, which is predominately pentanes and
cyclopentanes, from heavy naphtha which contains the hexanes and heavier hydrocarbons necessary for the catalytic reformer feed. The feed to the “light ends”
distillation process is usually the full range naphtha distillate from the atmospheric
crude distillation unit overhead condensate drum. In many cases the distillates from
stabilizing cracker and reformer products are added to the crude unit overhead
distillate to be included in the “light ends” unit feed.
A typical process configuration for this unit is given in the flow diagram (Fig. 1).
200
D.S.J. Jones