ASTM D4463/D4463M-96(2013)e1
(Guide)Standard Guide for Metals Free Steam Deactivation of Fresh Fluid Cracking Catalysts
Standard Guide for Metals Free Steam Deactivation of Fresh Fluid Cracking Catalysts
SIGNIFICANCE AND USE
4.1 In general, steam treatment of FCC catalyst can be used either to compare a series of cracking catalysts at a simulated equilibrium condition or conditions, or to simulate the equilibrium condition of a specific cracking unit and a specific catalyst. This guide gives an example for the first purpose and an approach for the latter purpose.
SCOPE
1.1 This guide covers the deactivation of fresh fluid catalytic cracking (FCC) catalyst by hydrothermal treatment prior to the determination of the catalytic cracking activity in the microactivity test (MAT).
1.2 The hydrothermal treatment of fresh FCC catalyst, prior to the MAT, is important because the catalytic activity of the catalyst in its fresh state is an inadequate measure of its true commercial performance. During operation in a commercial cracking unit, the catalyst is deactivated by thermal, hydrothermal and chemical degradation. Therefore, to maintain catalytic activity, fresh catalyst is added (semi) continuously to the cracking unit, to replace catalyst lost through the stack or by withdrawal, or both. Under steady state conditions, the catalyst inventory of the unit is called equilibrium catalyst. This catalyst has an activity level substantially below that of fresh catalyst. Therefore, artificially deactivating a fresh catalyst prior to determination of its cracking activity should provide more meaningful catalyst performance data.
1.3 Due to the large variations in properties among fresh FCC catalyst types as well as between commercial cracking unit designs or operating conditions, or both, no single set of steam deactivation conditions is adequate to artificially simulate the equilibrium catalyst for all purposes.
1.3.1 In addition, there are many other factors that will influence the properties and performance of the equilibrium catalyst. These include, but are not limited to: deposition of heavy metals such as Ni, V, Cu; deposition of light metals such as Na; contamination from attrited refractory linings of vessel walls. Furthermore, commercially derived equilibrium catalyst represents a distribution of catalysts of different ages (from fresh to >300 days). Despite these apparent problems, it is possible to obtain reasonably close agreement between the performances of steam deactivated and equilibrium catalysts. It is also recognized that it is possible to steam deactivate a catalyst so that its properties and performance poorly represent the equilibrium. It is therefore recommended that when assessing the performance of different catalyst types, a common steaming condition be used. Catalyst deactivation by metals deposition is not addressed in this guide, but is addressed in Guide D7206/D7206M.
1.4 This guide offers two approaches to steam deactivate fresh catalysts. The first part provides specific sets of conditions (time, temperature and steam pressure) that can be used as general pre-treatments prior to comparison of fresh FCC catalyst MAT activities (Test Method D3907) or activities plus selectivities (Test Method D5154).
1.4.1 The second part provides guidance on how to pretreat catalysts to simulate their deactivation in a specific FCCU and suggests catalyst properties which can be used to judge adequacy of the simulation. This technique is especially useful when examining how different types of catalyst may perform in a specific FCCU, provided no other changes (catalyst addition rate, regenerator temperature, contaminant metals levels, etc.) occur. This approach covers catalyst physical properties that can be used as monitors to indicate the closeness to equilibrium catalyst properties.
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard....
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Designation: D4463/D4463M − 96 (Reapproved 2013)
Standard Guide for
Metals Free Steam Deactivation of Fresh Fluid Cracking
Catalysts
This standard is issued under the fixed designation D4463/D4463M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Editorially changed 1.3.1 and 2.1 in March 2013.
1. Scope fresh to >300 days). Despite these apparent problems, it is
possible to obtain reasonably close agreement between the
1.1 This guide covers the deactivation of fresh fluid cata-
performancesofsteamdeactivatedandequilibriumcatalysts.It
lytic cracking (FCC) catalyst by hydrothermal treatment prior
is also recognized that it is possible to steam deactivate a
to the determination of the catalytic cracking activity in the
catalyst so that its properties and performance poorly represent
microactivity test (MAT).
the equilibrium. It is therefore recommended that when assess-
1.2 The hydrothermal treatment of fresh FCC catalyst, prior
ing the performance of different catalyst types, a common
to the MAT, is important because the catalytic activity of the
steaming condition be used. Catalyst deactivation by metals
catalyst in its fresh state is an inadequate measure of its true
deposition is not addressed in this guide, but is addressed in
commercial performance. During operation in a commercial
Guide D7206/D7206M.
cracking unit, the catalyst is deactivated by thermal, hydrother-
1.4 This guide offers two approaches to steam deactivate
mal and chemical degradation. Therefore, to maintain catalytic
fresh catalysts. The first part provides specific sets of condi-
activity, fresh catalyst is added (semi) continuously to the
tions (time, temperature and steam pressure) that can be used
cracking unit, to replace catalyst lost through the stack or by
as general pre-treatments prior to comparison of fresh FCC
withdrawal, or both. Under steady state conditions, the catalyst
catalyst MAT activities (Test Method D3907) or activities plus
inventory of the unit is called equilibrium catalyst. This
selectivities (Test Method D5154).
catalyst has an activity level substantially below that of fresh
1.4.1 The second part provides guidance on how to pretreat
catalyst. Therefore, artificially deactivating a fresh catalyst
catalysts to simulate their deactivation in a specific FCCU and
prior to determination of its cracking activity should provide
suggests catalyst properties which can be used to judge
more meaningful catalyst performance data.
adequacy of the simulation. This technique is especially useful
1.3 Due to the large variations in properties among fresh
whenexamininghowdifferenttypesofcatalystmayperformin
FCC catalyst types as well as between commercial cracking
a specific FCCU, provided no other changes (catalyst addition
unit designs or operating conditions, or both, no single set of
rate, regenerator temperature, contaminant metals levels, etc.)
steam deactivation conditions is adequate to artificially simu-
occur. This approach covers catalyst physical properties that
late the equilibrium catalyst for all purposes.
canbeusedasmonitorstoindicatetheclosenesstoequilibrium
1.3.1 In addition, there are many other factors that will
catalyst properties.
influence the properties and performance of the equilibrium
1.5 The values stated in either SI units or inch-pound units
catalyst. These include, but are not limited to: deposition of
are to be regarded separately as standard. The values stated in
heavy metals such as Ni,V, Cu; deposition of light metals such
each system may not be exact equivalents; therefore, each
as Na; contamination from attrited refractory linings of vessel
system shall be used independently of the other. Combining
walls. Furthermore, commercially derived equilibrium catalyst
values from the two systems may result in non-conformance
represents a distribution of catalysts of different ages (from
with the standard.
1.6 This standard does not purport to address all of the
This guide is under the jurisdiction ofASTM Committee D32 on Catalysts and
safety concerns, if any, associated with its use. It is the
is the direct responsibility of Subcommittee D32.04 on Catalytic Properties.
responsibility of the user of this standard to establish appro-
Current edition approved March 1, 2013. Published March 2013. Originally
priate safety and health practices and determine the applica-
approved in 1985. Last previous edition approved in 2012 as D4463/
D4463M–96(2012)e1. DOI: 10.1520/D4463_D4463M-96R13E01.
bility of regulatory limitations prior to use.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D4463/D4463M − 96 (2013)
2. Referenced Documents 5.4 In fixed bed steaming, the temperature gradient through
2 the catalyst bed should be kept as small as possible and should
2.1 ASTM Standards:
not exceed 4°C [7.2°F]. In fluid bed steaming the bed tempera-
D3663 Test Method for Surface Area of Catalysts and
ture must be homogeneous.
Catalyst Carriers
D3907 Test Method for Testing Fluid Catalytic Cracking
5.5 Heating and cooling of the catalyst must be performed
(FCC) Catalysts by Microactivity Test in the reactor under a flow of dry nitrogen.
D3942 Test Method for Determination of the Unit Cell
5.6 Precautions must be taken to achieve uniform contact of
Dimension of a Faujasite-Type Zeolite
the steam with the bed.
D4365 Test Method for Determining Micropore Volume and
Zeolite Area of a Catalyst
6. Sampling
D5154 TestMethodforDeterminingActivityandSelectivity
6.1 Asuitable sampling procedure is needed. Practice E105
of Fluid Catalytic Cracking (FCC) Catalysts by Microac-
is appropriate.
tivity Test
D7206/D7206M Guide for Cyclic Deactivation of Fluid
7. Sample Preparation
Catalytic Cracking (FCC) Catalysts with Metals
E105 Practice for Probability Sampling of Materials
7.1 No sample preparation is necessary if the catalyst is
E177 Practice for Use of the Terms Precision and Bias in
heated slowly during preheating (non-shock steaming).
ASTM Test Methods
7.2 If the sample is introduced directly into a preheated
E456 Terminology Relating to Quality and Statistics
steaming reactor, (shock-steaming) it is desirable to predry the
E691 Practice for Conducting an Interlaboratory Study to
sample for about one hour at about 550°C [1022°F] to prevent
Determine the Precision of a Test Method
excessive catalyst loss.
3. Summary of Guide
8. Procedure
3.1 A sample of fresh fluid cracking catalyst is placed in a
reactor, either fixed bed or preferably fluid bed, and is
8.1 Procedure for fluid bed and fixed bed steam treatment
contacted with steam at elevated temperature. This treatment
(non-shock steaming):
causes partial deactivation of the catalyst.
8.1.1 With the reactor heated to 300°C [572°F] or lower,
load the reactor with catalyst.
NOTE 1—In a fixed bed reactor, material containing sulfates, chlorides,
etc. can result in significant additional chemical deactivation.
8.1.2 Start nitrogen flow to the reactor at a flow velocity of
3 cm/s [0.1 ft/s].
3.2 The catalyst is withdrawn from the reactor and may be
8.1.3 Heat the reactor at the maximum rate until a tempera-
subjected to an activity or activity plus selectivity
ture of 600°C [1112°F] is reached.
determination, by using the microactivity test (Test Methods
8.1.4 Keep the temperature constant at 600°C [1112°F] for
D3907 or D5154).
30 min in order to remove volatile material from the catalyst.
4. Significance and Use
8.1.5 Heat the reactor at the maximum rate until the desired
4.1 In general, steam treatment of FCC catalyst can be used steaming temperature is reached; for example, at 760, 788 or
either to compare a series of cracking catalysts at a simulated 800°C [1400, 1450 or 1472°F] 62°C [63.6°F].
equilibrium condition or conditions, or to simulate the equilib-
8.1.6 Stop the nitrogen flow and start a flow of undiluted
rium condition of a specific cracking unit and a specific
steam at atmospheric pressure and at constant temperature of
catalyst. This guide gives an example for the first purpose and
760, 788 or 800°C [1400, 1450 or 1472°F]. Continue this
an approach for the latter purpose.
steam flow for 5 hours. For fixed bed operation, keep the steam
flow velocity at 5 6 1 cm/s [0.16 6 0.
...
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