supplies to the manufacture of explosives. Though not readily biodegradable, one
of the earliest and still one of the most active detergent ingredients is
dodecylbenzene sulfonate. This was obtained by first alkylating dodecene with
benzene according to the technology developed independently by UOP and Standard Oil of California (now Chevron). Dodecene, or propylene tetramer, was
readily produced by the oligomerization of propylene over SPA catalyst.
Still, at the apex of its success, the catalytic condensation process was used
mostly for the production of gasoline. During World War II, an important component in the aviation fuels used in fighter airplanes of that time was hydrocodimer,
described more fully below. This together with cumene, also derived from phosphoric acid catalyst operations, was credited with being a significant factor in
Britain’s success in the Battle of Britain. The typical refinery product was known
as polymer gasoline or “polygasoline” even though in reality it consisted mostly of
fairly simple dimers and trimers. At one time there were as many as 300–400
catalytic condensation units producing gasoline alone. Today, production of polymer gasoline is less significant, but the catalytic condensation process is still the
preferred route to olefin dimers and oligomers and, despite the inroads made by
zeolitic catalysts, is still widely used for the production of cumene. Based on the
current demand for SPA catalyst, it may be estimated that about 40 % is for
gasoline, 40 % for higher olefins (plasticizer olefins), and the balance 20 % for
cumene applications.
Catalytic Condensation Process for Gasoline Production
Figure 1 illustrates a simplified process flow diagram for gasoline production using
a tubular reactor.
The tubular reactor system has the catalyst in the tubes, and condensate or boiler
feedwater is used to remove the exothermic heat of reaction and to raise steam on
the shell side. The reactants are circulated through the catalyst, and the effluent is
cooled and passed to a stabilizer column. An LPG (propane–butane) recycle may be
maintained to control the concentration of olefins in the feed and the heat release in
the system. Usually, the olefin concentration in the feed to the reactor is maintained
at not more than about 50 %. The gasoline produced is removed via the bottoms of
the stabilizer. Figure 2 illustrates a similar diagram using an adiabatic plug flow
reactor.
Adiabatic plug flow reactors do not have provisions for steam generation within
the reactor. Instead, an LPG interbed quench is used to control the temperature rise
within the reactor with as many as five catalyst beds being arranged within the
vessel. The product is sent to a flash drum in which partial condensation occurs, and
the liquid is sent to a stabilizer column. The bottom from this column is the final
gasoline product. With this type of reactor, the concentration of olefins in the feed is
usually limited to about 30 %. From an energy point of view, it is less efficient than
a tubular reactor, but it is more economical to build.
For practical purposes, the products made by either system are almost identical.
Olefin Condensation
461
of the earliest and still one of the most active detergent ingredients is
dodecylbenzene sulfonate. This was obtained by first alkylating dodecene with
benzene according to the technology developed independently by UOP and Standard Oil of California (now Chevron). Dodecene, or propylene tetramer, was
readily produced by the oligomerization of propylene over SPA catalyst.
Still, at the apex of its success, the catalytic condensation process was used
mostly for the production of gasoline. During World War II, an important component in the aviation fuels used in fighter airplanes of that time was hydrocodimer,
described more fully below. This together with cumene, also derived from phosphoric acid catalyst operations, was credited with being a significant factor in
Britain’s success in the Battle of Britain. The typical refinery product was known
as polymer gasoline or “polygasoline” even though in reality it consisted mostly of
fairly simple dimers and trimers. At one time there were as many as 300–400
catalytic condensation units producing gasoline alone. Today, production of polymer gasoline is less significant, but the catalytic condensation process is still the
preferred route to olefin dimers and oligomers and, despite the inroads made by
zeolitic catalysts, is still widely used for the production of cumene. Based on the
current demand for SPA catalyst, it may be estimated that about 40 % is for
gasoline, 40 % for higher olefins (plasticizer olefins), and the balance 20 % for
cumene applications.
Catalytic Condensation Process for Gasoline Production
Figure 1 illustrates a simplified process flow diagram for gasoline production using
a tubular reactor.
The tubular reactor system has the catalyst in the tubes, and condensate or boiler
feedwater is used to remove the exothermic heat of reaction and to raise steam on
the shell side. The reactants are circulated through the catalyst, and the effluent is
cooled and passed to a stabilizer column. An LPG (propane–butane) recycle may be
maintained to control the concentration of olefins in the feed and the heat release in
the system. Usually, the olefin concentration in the feed to the reactor is maintained
at not more than about 50 %. The gasoline produced is removed via the bottoms of
the stabilizer. Figure 2 illustrates a similar diagram using an adiabatic plug flow
reactor.
Adiabatic plug flow reactors do not have provisions for steam generation within
the reactor. Instead, an LPG interbed quench is used to control the temperature rise
within the reactor with as many as five catalyst beds being arranged within the
vessel. The product is sent to a flash drum in which partial condensation occurs, and
the liquid is sent to a stabilizer column. The bottom from this column is the final
gasoline product. With this type of reactor, the concentration of olefins in the feed is
usually limited to about 30 %. From an energy point of view, it is less efficient than
a tubular reactor, but it is more economical to build.
For practical purposes, the products made by either system are almost identical.
Olefin Condensation
461