159
chromium-alumina catalyst (Cr 2 O 3 /Al 2 O 3 ; with 18–20 wt% of Cr) is used for the
PDH reaction. Efficient reactor system to drive selective dehydrogenation of propane to propylene and regeneration of the catalyst are the most critical parameters
in designing Catofin PDH plants. Since the dehydrogenation reaction is endothermic, a high temperature is required to drive the reaction which leads to the coke
deposition on the catalyst. Thus, dehydrogenation and catalyst regeneration steps
are carried out in short intervals of every 10–12 min with short periods of purging
and evacuation operations in-between. Coke deposition results in loss of catalyst
activity and decrease bed temperature. Regeneration of the catalyst is achieved by
burning deposited coke on the catalyst by blowing hot air on the catalyst bed which
simultaneously recovers the bed temperature under oxidizing conditions. The average lifetime of the catalyst is 2–3 years in industrial operation and the catalyst activity gradually decreases over the time due to the loss of active metal and sintering of
the active metal particles.
Another key feature of Catofin PDH technology is the use of heat generating
material (HGM) [34] developed by Clariant. HGM is a proprietary metal-oxide
material suitable to produce heat and drive the endothermic dehydrogenation reaction to increase yields. HGM also reduces energy requirement and emissions. As a
result, HGM enhances the performance advantages of Catofin technology and catalysts. A number of (>10 Nos) Catofin PDH plants are operational in the world and
INEOS, Europe’s largest petrochemicals company, is constructing one of the largest
Catofin PDH plants (having capacity of 750,000 tons/year) at Antwerp, Belgium
which is expected to come on stream in 2023 [35].
Oleflex ™ PDH process developed by UOP is a continuous catalytic dehydrogenation process. In Oleflex process, a fluidized bed reactor along with catalyst regeneration unit is used. Propane dehydrogenation is performed over Pt-Sn-based
catalyst at the temperature range of 630–650 °C and 1–3 bar pressure. The catalyst
is regenerated by burning coke and re-dispersing Pt by chlorine-air mixture. The life
of the catalyst is 1–3 years. UOP has continuously improved catalyst performance
for the Oleflex process since the arrival of the first-generation catalyst (DeH-6) in
1990 followed by second Generation catalyst (DeH-8, in 1992), third Gen
(DeH-10 in 1993), fourth Gen (DeH-12 in 1996), fifth Gen (DeH-14 in 2001), sixth
Gen (DeH-16 in 2007), seventh Gen (DeH-18 in 2014), and further improvement to
DeH-24 and DeH-26 [36]. The new generation DeH catalyst is based on alkaline
metal-doped Pt/Al 2 O 3 catalyst with 0.3–0.5 wt% Pt loading promoted with a second
metal such as Sn, Zn, or Cu. The continuous improvement in the next generation
catalyst performance indicates there is tremendous scope in improving the activity
and stability of a catalyst system by optimizing metal loading, modifying synthesis
parameters, and introducing a second metal to optimize the cost as well as the performance of the catalyst. The new generation DeH catalyst provides 30% higher
coking stability and has much higher attrition resistant while offering superior activity and selectivity. The superior performance and improved attrition resistance have
helped UOP to design >1000 KTA PDH plant. The main advantages of the Oleflex
process are the ability to continuously regenerate catalysts without interrupting propylene production and low energy consumption. Because of this, Oleflex process
C3-Based Petrochemicals: Recent Advances in Processes and Catalysts
chromium-alumina catalyst (Cr 2 O 3 /Al 2 O 3 ; with 18–20 wt% of Cr) is used for the
PDH reaction. Efficient reactor system to drive selective dehydrogenation of propane to propylene and regeneration of the catalyst are the most critical parameters
in designing Catofin PDH plants. Since the dehydrogenation reaction is endothermic, a high temperature is required to drive the reaction which leads to the coke
deposition on the catalyst. Thus, dehydrogenation and catalyst regeneration steps
are carried out in short intervals of every 10–12 min with short periods of purging
and evacuation operations in-between. Coke deposition results in loss of catalyst
activity and decrease bed temperature. Regeneration of the catalyst is achieved by
burning deposited coke on the catalyst by blowing hot air on the catalyst bed which
simultaneously recovers the bed temperature under oxidizing conditions. The average lifetime of the catalyst is 2–3 years in industrial operation and the catalyst activity gradually decreases over the time due to the loss of active metal and sintering of
the active metal particles.
Another key feature of Catofin PDH technology is the use of heat generating
material (HGM) [34] developed by Clariant. HGM is a proprietary metal-oxide
material suitable to produce heat and drive the endothermic dehydrogenation reaction to increase yields. HGM also reduces energy requirement and emissions. As a
result, HGM enhances the performance advantages of Catofin technology and catalysts. A number of (>10 Nos) Catofin PDH plants are operational in the world and
INEOS, Europe’s largest petrochemicals company, is constructing one of the largest
Catofin PDH plants (having capacity of 750,000 tons/year) at Antwerp, Belgium
which is expected to come on stream in 2023 [35].
Oleflex ™ PDH process developed by UOP is a continuous catalytic dehydrogenation process. In Oleflex process, a fluidized bed reactor along with catalyst regeneration unit is used. Propane dehydrogenation is performed over Pt-Sn-based
catalyst at the temperature range of 630–650 °C and 1–3 bar pressure. The catalyst
is regenerated by burning coke and re-dispersing Pt by chlorine-air mixture. The life
of the catalyst is 1–3 years. UOP has continuously improved catalyst performance
for the Oleflex process since the arrival of the first-generation catalyst (DeH-6) in
1990 followed by second Generation catalyst (DeH-8, in 1992), third Gen
(DeH-10 in 1993), fourth Gen (DeH-12 in 1996), fifth Gen (DeH-14 in 2001), sixth
Gen (DeH-16 in 2007), seventh Gen (DeH-18 in 2014), and further improvement to
DeH-24 and DeH-26 [36]. The new generation DeH catalyst is based on alkaline
metal-doped Pt/Al 2 O 3 catalyst with 0.3–0.5 wt% Pt loading promoted with a second
metal such as Sn, Zn, or Cu. The continuous improvement in the next generation
catalyst performance indicates there is tremendous scope in improving the activity
and stability of a catalyst system by optimizing metal loading, modifying synthesis
parameters, and introducing a second metal to optimize the cost as well as the performance of the catalyst. The new generation DeH catalyst provides 30% higher
coking stability and has much higher attrition resistant while offering superior activity and selectivity. The superior performance and improved attrition resistance have
helped UOP to design >1000 KTA PDH plant. The main advantages of the Oleflex
process are the ability to continuously regenerate catalysts without interrupting propylene production and low energy consumption. Because of this, Oleflex process
C3-Based Petrochemicals: Recent Advances in Processes and Catalysts