before entering into the first reactor. Thus, the reactors are continuously supplied
with freshly regenerated catalyst, and product yields are maintained at a constant
level. The regeneration and reactor sections of the unit are easily isolated to permit
a shutdown of the regeneration system for normal inspection or maintenance
without interrupting the processing of naphtha feed.
A few years after the introduction of the UOP CCR Platforming process, another
continuously regenerable process design was offered by the Institut Franc ¸ais du
Pe ´trole (IFP). The IFP continuous reforming units designed by the Institut Franc ¸ais
du Pe ´trole employ reactors that are located side by side, and the catalyst transfer is
accomplished through a conveying system with piping between reactors.
Secondary Recovery
The need for effective liquid recovery is more critical for the low pressure operations of the CCR unit. The advantage of the increased aromatic, hydrogen, and C 5 +
yields at low pressure can be lost if the proper recovery system is not installed. At
low pressure in the gas-liquid separator, the flash pressure has been reduced
allowing heavier hydrocarbons (C 4 –C 6 +) to leave with the vapor resulting in lost
C 5 + product and lower purity hydrogen gas.
One improved separation scheme involves first separating the reactor effluent in
the separator into vapor and liquid followed by recompressing the vapor with a
net gas booster compressor with discharge into a drum or absorber vessel.
The liquid from the separator is also pumped into the same drum/absorber for
recontacting at higher pressure. This will allow a better gas-liquid separation
leading to increased liquid recovery and higher purity hydrogen. Another
method involves chilling the net separator gas with a refrigeration system and
performing vapor-liquid separation at a low temperature. Other proprietary
systems have been developed such as UOP’s Recovery Plus
TM system
(Lapinski et al. 2004).
Unit Improvements
The design of reforming units has been constantly improved over time with
innovations in equipment and process features. After many decades in operation,
many reforming units need replacement of equipment to maintain good reliability.
Improved design features include updated reactor internals including improved
inlet distributors and higher strength center pipes, logic systems that minimize
mechanical stresses during start-ups and shutdowns, improved valves in the catalyst
transfer lines for lower catalyst abrasion and attrition, and improved catalyst lift
lines to reduce impact of the catalyst pills with the reactor walls. Another improvement is the replacement of older electronic systems that control the regeneration
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M.P. Lapinski et al.
with freshly regenerated catalyst, and product yields are maintained at a constant
level. The regeneration and reactor sections of the unit are easily isolated to permit
a shutdown of the regeneration system for normal inspection or maintenance
without interrupting the processing of naphtha feed.
A few years after the introduction of the UOP CCR Platforming process, another
continuously regenerable process design was offered by the Institut Franc ¸ais du
Pe ´trole (IFP). The IFP continuous reforming units designed by the Institut Franc ¸ais
du Pe ´trole employ reactors that are located side by side, and the catalyst transfer is
accomplished through a conveying system with piping between reactors.
Secondary Recovery
The need for effective liquid recovery is more critical for the low pressure operations of the CCR unit. The advantage of the increased aromatic, hydrogen, and C 5 +
yields at low pressure can be lost if the proper recovery system is not installed. At
low pressure in the gas-liquid separator, the flash pressure has been reduced
allowing heavier hydrocarbons (C 4 –C 6 +) to leave with the vapor resulting in lost
C 5 + product and lower purity hydrogen gas.
One improved separation scheme involves first separating the reactor effluent in
the separator into vapor and liquid followed by recompressing the vapor with a
net gas booster compressor with discharge into a drum or absorber vessel.
The liquid from the separator is also pumped into the same drum/absorber for
recontacting at higher pressure. This will allow a better gas-liquid separation
leading to increased liquid recovery and higher purity hydrogen. Another
method involves chilling the net separator gas with a refrigeration system and
performing vapor-liquid separation at a low temperature. Other proprietary
systems have been developed such as UOP’s Recovery Plus
TM system
(Lapinski et al. 2004).
Unit Improvements
The design of reforming units has been constantly improved over time with
innovations in equipment and process features. After many decades in operation,
many reforming units need replacement of equipment to maintain good reliability.
Improved design features include updated reactor internals including improved
inlet distributors and higher strength center pipes, logic systems that minimize
mechanical stresses during start-ups and shutdowns, improved valves in the catalyst
transfer lines for lower catalyst abrasion and attrition, and improved catalyst lift
lines to reduce impact of the catalyst pills with the reactor walls. Another improvement is the replacement of older electronic systems that control the regeneration
256
M.P. Lapinski et al.