D. Bazer-Bachi, Axens, Salindres, France; M. HUTCHINSON, Axens,
Princeton, New Jersey (U.S.); P.-Y. LE GOFF, F. LE PELTIER and C.
PIERRE, Axens, Rueil-Malmaison, France
Even in the context of the energy transition—with gasoline demand expected
catalytic reforming process will continue to be a key process in refineries around
the world to produce high-octane gasoline and aromatics. High-octane gasoline
will meet the needs of high-compression engines and increase the efficiency of the
internal combustion engine fleet. Refiners are also being challenged to process
more difficult feedstock (including highly paraffinic bio-naphtha), requiring
higher severity and improved catalyst formulations. Additionally, some refiners
will have a viable alternative to reduce their Scope 3 emissions by extracting
the aromatics produced by catalytic reformers to be used as petrochemical feedstock.
Hydrogen (H2) will also remain an important byproduct used in distillate
hydrotreaters, especially as more difficult-to-treat bioprocess diesels are
mixed in the pool.
The principle means of obtaining an increase in octane
and aromatics is the conversion of paraffins and cycloparaffins (naphthenes)
into aromatics (FIG. 1).
To achieve these objectives, specialized
multi-functional precious metal catalysts are employed in fixed-bed or moving-bed
This article is divided into two sections: the first recalls
the initial work performed in the early 2000s to improve the manufacture of continuous
catalytic reforming (CCR) catalysts, while the second section is devoted to recent
developments in the fixed-bed and CCR catalysts fields. The objective is to highlight
that, even if catalyst development in reforming has been ongoing for more than
60 yr, opportunities can be seized to improve unit profitability.
initIal work on catalyst manufacturing optimiZation
To improve the economics, the key point is to mitigate
side reactions such as hydrogenolysis and hydrocracking (FIG. 2). To achieve this target,
various additives, also called modifiers, have been used over the past few decades.2
A key challenge, however, is the scale-up of the laboratory recipe to industrial
scale while ensuring a homogenous distribution of the additives throughout the
carrier. The impact of this homogenous distribution is described in literature3
and even patented.4
an example of such developments, a significant amount of work was completed in
the early 2000s by the authors’ company on the Pt/Sn catalyst formulation to
ensure better distribution of tin and its interaction with platinum. FIG. 3 illustrates
the close control of the Pt/Sn ratio throughout the catalyst particle diameter
for two catalysts, A and B.
As seen in TABLE 1, an
improvement in Pt-Sn metallic phase homogeneity (A vs. B) leads to a
substantial enhancement in catalytic performance.5
knowledge acquired in the last 20 yr has been applied to improve and develop
new generations of reforming catalysts. The impact is discussed below, first
for fixed-bed platinum rhenium formulated catalyst and then for CCR type platinum
Fixed-bed/cyclic catalyst developments
the catalyst manufacturing process. Using a microprobe
analysis (FIG. 4),
it is possible to obtain a two-dimensional picture of the distribution of modifiers
on the catalyst particle—higher
concentration areas are represented by large red spots, while a more homogenous
distribution appears similar to a starry sky with little red spots. The pictures
in FIG. 4 taken
of catalyst using different production schemes show how the modifier is added
can significantly impact the distribution of the modifier and have a direct impact
on unit performance, as seen in the pilot test results in FIG. 5.
start-of-run conditions, the activity improvement is 4°C–5°C, while the de-activation
rate is reduced by almost 25%.
improvements, for the same catalytic formation, are achieved with a slightly
higher selectivity. In reforming, there is typically a tradeoff between
activity and selectivity—the
higher the activity, the lower the selectivity—but this is not the case with improvement in the
manufacturing process. This definitively supports that a factor of paramount
importance is the control of the quality of the modifiers distribution all
across the carrier, leading to both improvement in activity and selectivity.
Catalyst manufacturing scale-up and formulation
optimization. This progression of catalyst scale-up has also provided
new opportunities for formulations that initially lacked activity and
stability. Indeed, low-activity and low-stability catalysts have a direct
impact on unit profitability, as they reduce either the time-of-stream factor
or necessitate a reduction in unit capacity. Therefore, such catalysts, even if
selectivity was on the high side, could not find their place on the market.
the optimization of the manufacturing scheme, it is now possible—while maintaining the
same selectivity (orange squares and blue dots in FIG. 6)—to improve the activity by 10°C and improve the stability
by decreasing the deactivation rate by a factor of two.
to platinum/rhenium reforming catalyst without modifier, the optimized
manufacturing scheme makes it possible to achieve the same stability with a
significant selectivity improvement of ~1.6 wt%.
the same formulation, the activity and stability improvements (linked to the
optimized manufacturing scheme) have led to the development of a new family of reforming
catalysts to respond more specifically to each customer’s needs. Given that
each unit has specific constraints (activity, stability, specific naphtha diet),
a one-size-fits-all approach does not allow the customer to maximize
Impact on economics. Based on these improvements, comparative
economic studies were conducted to determine the economic benefit a customer can
expect switching to this new generation catalyst compared to the previous
catalyst generation. The study was based on a 40,000-bpd reformer capacity for Cases
1, 2 and 4 and for a 44,000-bpd capacity for Case 3. The product valorizations
are given in TABLE 2.
on local unit constraints, these new products enable increased capacity, improved
catalyst activity and higher unit profitability.
added value detailed in TABLE
3 is defined in Eq. 1, where the index i considers H2, fuel gas, liquefied
petroleum gas (LPG) and reformate production:
Added value = ∑4i=1 pricei × flowi – CostNaphtha × flownaphtha (1)
CCR catalyst developments. For CCR catalysts, the same
optimizations in manufacturing and formulation were applied. First, an
optimization of the catalytic formulation showed it was possible to achieve
higher selectivity for almost all activity compared to the base catalyst, as
shown in FIG. 7
with blue dots and grey triangles, respectively.
to the platinum rhenium catalyst used in fixed-bed reformers, some units have
margins in terms of activity where the optimization of the catalyst design is of
paramount importance. If the activity debit was initially quite large (green diamonds
in FIG. 7)
following an adjustment of manufacturing, it is possible to maintain the
same selectivity while improving the activity by 5°C (green diamonds and orange squares in FIG. 7).
with any CCR catalyst change, the propensity for coke production must be
considered. For the latest generation catalyst, a slight increase in coke make
is projected and should be fully compatible with a unit over-design coke
is particularly true considering the high hydrothermal stability of these catalysts,
which allow the regenerator to operate at higher oxygen content at the burning
inlet of the regenerator with minimal impact on the surface area loss.
cases, units running at lower-than-design severity and non-continuous
regenerator operation can take advantage of this slight increase in coke make
to resume continuous regenerator operation.
production vs. the Base case for the same operating conditions and time on-stream
is shown in TABLE 4.
Based on these improvements,
considering the same basis as those of TABLE 2, significant economic benefit can be
achieved (TABLE 5).
in FIG. 8,
it is ultimately possible to fine-tune catalyst formulation to unit constraints
(coke burning capacity and maximum operating temperature).
addition to these selectivity improvements, the higher H2 production
has a direct impact on CO2 emissions. Presently, the main source of H2
comes from steam methane reforming (SMR)—for each ton of pure H2, 8 t–12 t of CO2
are produced, leading to the grey hydrogen classification.6
TABLE 6 considers
a 50,000-bpd reforming unit to demonstrate the CO2 emissions
reduction linked to the reduction of grey hydrogen importation. As a result,
for units having the margin for reduced activity, this generation of new catalyst
also leads to a reduction in CO2 emissions.
reforming catalysts were based on platinum, platinum rhenium or platinum tin on
chlorinated alumina.7 To increase the selectivity of these catalysts,
modifiers are added by certain manufacturers to improve unit profitability by
increasing selectivity while sacrificing catalyst activity.8 An
additional side effect of using these modifiers is a more complex manufacturing
scheme. After the optimization of the manufacturing scheme, it is possible to
unlock this typical selectivity/activity trend by improving activity and/or
selectivity without offsetting the other.
Moreover, these process optimizations make it possible
to reconsider the use of some old high-selectivity formulations, which were
limited by low stability and low activity. These R&D activities and
manufacturing improvements allow the catalyst to be fine-tuned, depending on
customer constraints, by moving away from the one-size-fits-all approach. HP
DELPHINE BAZER-BACHI is Development
and Industrialization Team Manager, Industrial Operations Business Division, for
Axens. She began her professional career in 2005 as a Research Engineer at IFPEN. She
acquired 10 yr of R&D experience in the field of heterogeneous catalysis,
with a focus on inorganic chemistry and carrier shaping applied to various
topics such as hydrocracking, biodiesel, separations and reforming. In 2016,
she joined Axens as a Development and Industrialization Engineer and is in
charge of the development of different catalysts and their industrialization in
Axens industrial sites, with a specialization in reforming catalysts and
carriers (alumina synthesis, shaping and catalyst formulation). Dr. Bazer-Bachi
holds an engineering degree from the École Nationale Supérieure des Industries
Chimiques in Nancy (ENSIC) and a PhD (chemical engineering) from Université de Lorraine.
MATTHEW HUTCHINSON is Senior Technology
Manager, Gasoline and Petrochemical Technologies, for Axens. He brings more than 25 yr of refining experience to
his current role at Axens, where manages the Reforming and Aromatic Technology
team. In this role, his group is responsible for process licensing (grassroots
and revamps solutions) and technical catalyst support, projections and technical
service. Hutchinson has played a key role in the North American reforming
support, development of improved reforming internals and implementation of
Connect’In, Axens’ digital monitoring solution over the last 7 yr. He graduated
from Cornell University with a BS degree in chemical engineering.
PIERRE-YVES LE GOFF is Global Market Manager Reforming and Paraffin Isomerization, Commercial Business
Division, Commercial Strategy and Customer Marketing Department, for Axens.
He began his professional career in 1995 as a Research Engineer
at Rhone Poulenc in France, where he acquired extensive R&D experience in a
variety of programs with major emphasis on inorganic synthesis and carrier
shaping. He joined Axens in 2000 as a Technical Manager for reforming and
naphtha hydrotreating applications. After several years in that position, Dr. le
Goff joined the Technology Development and Innovation department, where he was
in charge of mainly R&D projects in the field of reforming and aromatics.
He was appointed to his current position at the end of
2018, and is now responsible for the strategy and development of technical and
commercial departments in connection with R&D. Dr. le Goff holds an engineering
degree from the École
de Chimie de Mulhouse, an MBA from Université de la Sorbonne in Paris, and a PhD from
FABIENNE LE PELTIER is Product Development
Manager, New Development and Transformation Business Division, for Axens. She began her professional career as a Research Engineer at IFPEN
in the field of heterogeneous catalysis, specializing in metallic supported
catalysts for hydrogenation, dehydrogenation and reforming applications. She
joined the Axens Technical Service group in 2001 as Technical Advisor, and created
a laboratory network to organize spent catalysts and petroleum products
analysis and an analysis database to support technical service engineers in
their troubleshooting activities. In 2013, Dr. le Peltier joined the New
Development and Transformation Business Division, where she has also been
involved in the field of new product development and has set up various
characterization methods of catalysts. Dr. le Peltier holds an engineering degree from the École
de Chimie de Rennes, and a PhD in petroleum science from the Université de Paris VI.
CHRISTOPHE PIERRE is Reforming Product Line
Manager, Gasoline Product Line Technology and Technical Support Business
Division, for Axens. He joined
Axens in 2002 as a Process Engineer in the engineering department and moved
later as Project Manager for reforming and gasoline projects. Pierre joined the
technology group in 2007 and was in charge of reforming and isomerization
technologies related to gasoline pool problematics. In 2014, he became Technology
Team Manager in charge of aromatics proposals, and then gasoline proposals. In
2022, he was appointed as Reforming Product Line Manager in the Gasoline
Product Line Technology and Technical Support Business Division. Pierre holds
an engineering degree from the École Nationale Supérieure des Industries Chimiques and was post-graduated from IFP