ASTM D4463-96(2006)
(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
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.
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 D 3907) or activities plus selectivities (Test Method D 5154).
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 SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicabili...
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Designation:D4463–96 (Reapproved 2006)
Standard Guide for
Metals Free Steam Deactivation of Fresh Fluid Cracking
Catalysts
This standard is issued under the fixed designation D4463; 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.
1. Scope ing the performance of different catalyst types, a common
steaming condition be used. Catalyst deactivation by metals
1.1 This guide covers the deactivation of fresh fluid cata-
deposition is not addressed in this guide.
lytic cracking (FCC) catalyst by hydrothermal treatment prior
1.4 This guide offers two approaches to steam deactivate
to the determination of the catalytic cracking activity in the
fresh catalysts. The first part provides specific sets of condi-
microactivity test (MAT).
tions (time, temperature and steam pressure) that can be used
1.2 The hydrothermal treatment of fresh FCC catalyst, prior
as general pre-treatments prior to comparison of fresh FCC
to the MAT, is important because the catalytic activity of the
catalyst MAT activities (Test Method D3907) or activities plus
catalyst in its fresh state is an inadequate measure of its true
selectivities (Test Method D5154).
commercial performance. During operation in a commercial
1.4.1 The second part provides guidance on how to pretreat
cracking unit, the catalyst is deactivated by thermal, hydrother-
catalysts to simulate their deactivation in a specific FCCU and
mal and chemical degradation. Therefore, to maintain catalytic
suggests catalyst properties which can be used to judge
activity, fresh catalyst is added (semi) continuously to the
adequacy of the simulation. This technique is especially useful
cracking unit, to replace catalyst lost through the stack or by
whenexamininghowdifferenttypesofcatalystmayperformin
withdrawal, or both. Under steady state conditions, the catalyst
a specific FCCU, provided no other changes (catalyst addition
inventory of the unit is called equilibrium catalyst. This
rate, regenerator temperature, contaminant metals levels, etc.)
catalyst has an activity level substantially below that of fresh
occur. This approach covers catalyst physical properties that
catalyst. Therefore, artificially deactivating a fresh catalyst
canbeusedasmonitorstoindicatetheclosenesstoequilibrium
prior to determination of its cracking activity should provide
catalyst properties.
more meaningful catalyst performance data.
1.5 The values stated in SI units are to be regarded as
1.3 Due to the large variations in properties among fresh
standard. The values given in parentheses are for information
FCC catalyst types as well as between commercial cracking
only.
unit designs or operating conditions, or both, no single set of
1.6 This standard does not purport to address all of the
steam deactivation conditions is adequate to artificially simu-
safety concerns, if any, associated with its use. It is the
late the equilibrium catalyst for all purposes.
responsibility of the user of this standard to establish appro-
1.3.1 In addition, there are many other factors that will
priate safety and health practices and determine the applica-
influence the properties and performance of the equilibrium
bility of regulatory limitations prior to use.
catalyst. These include, but are not limited to: deposition of
heavy metals such as Ni,V, Cu; deposition of light metals such
2. Referenced Documents
as Na; contamination from attrited refractory linings of vessel
2.1 ASTM Standards:
walls. Furthermore, commercially derived equilibrium catalyst
D3663 Test Method for Surface Area of Catalysts and
represents a distribution of catalysts of different ages (from
Catalyst Carriers
fresh to >300 days). Despite these apparent problems, it is
D3907 Test Method for Testing Fluid Catalytic Cracking
possible to obtain reasonably close agreement between the
(FCC) Catalysts by Microactivity Test
performancesofsteamdeactivatedandequilibriumcatalysts.It
D3942 Test Method for Determination of the Unit Cell
is also recognized that it is possible to steam deactivate a
Dimension of a Faujasite-Type Zeolite
catalyst so that its properties and performance poorly represent
D4365 Test Method for Determining Micropore Volume
the equilibrium. It is therefore recommended that when assess-
and Zeolite Area of a Catalyst
This guide is under the jurisdiction ofASTM Committee D32 on Catalysts and
is the direct responsibility of Subcommittee D32.04 on Catalytic Properties. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2006. Published November 2006. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1985. Last previous edition approved in 2001 as D4463–96(2001). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D4463-96R06. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4463–96 (2006)
D5154 Test Method for Determining Activity and Selectiv- 7.2 If the sample is introduced directly into a preheated
ity of Fluid Catalytic Cracking (FCC) Catalysts by Micro- steaming reactor, (shock-steaming) it is desirable to predry the
activity Test sample for about one hour at about 550°C (1022°F) to prevent
E105 Practice for Probability Sampling Of Materials excessive catalyst loss.
E177 Practice for Use of the Terms Precision and Bias in
ASTM Test Methods 8. Procedure
E456 Terminology Relating to Quality and Statistics
8.1 Procedure for fluid bed and fixed bed steam treatment
E691 Practice for Conducting an Interlaboratory Study to
(non-shock steaming):
Determine the Precision of a Test Method
8.1.1 With the reactor heated to 300°C (572°F) or lower,
load the reactor with catalyst.
3. Summary of Guide
8.1.2 Start nitrogen flow to the reactor at a flow velocity of
3.1 A sample of fresh fluid cracking catalyst is placed in a
3 cm/s (0.1 ft/s).
reactor, either fixed bed or preferably fluid bed, and is 8.1.3 Heat the reactor at the maximum rate until a tempera-
contacted with steam at elevated temperature. This treatment
ture of 600°C (1112°F) is reached.
causes partial deactivation of the catalyst. 8.1.4 Keep the temperature constant at 600°C (1112°F) for
30 min in order to remove volatile material from the catalyst.
NOTE 1—In a fixed bed reactor, material containing sulfates, chlorides,
8.1.5 Heat the reactor at the maximum rate until the desired
etc. can result in significant additional chemical deactivation.
steaming temperature is reached; for example, at 760, 788 or
3.2 The catalyst is withdrawn from the reactor and may be
800°C (1400, 1450 or 1472°F) 6 2°C (6 3.6°F).
subjected to an activity or activity plus selectivity determina-
8.1.6 Stop the nitrogen flow and start a flow of undiluted
tion, by using the microactivity test (Test Methods D3907 or
steam at atmospheric pressure and at constant temperature
D5154).
(760, 788 or 800°C). Continue this steam flow for 5 hours. For
fixedbedoperation,keepthesteamflowvelocityat5 61cm/s
4. Significance and Use
(0.16 6 0.03 ft/s) at the desired deactivation temperature. For
4.1 In general, steam treatment of FCC catalyst can be used
fluidbedoperation,keepthesteamvelocityat3 61cm/s(0.10
either to compare a series of cracking catalysts at a simulated
6 0.03 ft/s).
equilibrium condition or conditions, or to simulate the equilib-
8.1.7 After 5 h, stop the steam flow and start nitrogen
rium condition of a specific cracking unit and a specific
flowing at 3 cm/s (0.10 ft/s) through the reactor.
catalyst. This guide gives an example for the first purpose and
8.1.8 Cooldownthereactortolessthan300°C(572°F).The
an approach for the latter purpose.
rate of cooling is not critical.
8.1.9 Remove the catalyst from the reactor and store in a
5. Apparatus
sealed bottle.
5.1 Fixed bed or fluid bed
...
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