ASTM D4824-13(2018)
(Test Method)Standard Test Method for Determination of Catalyst Acidity by Ammonia Chemisorption
Standard Test Method for Determination of Catalyst Acidity by Ammonia Chemisorption
SIGNIFICANCE AND USE
5.1 This test method can be used to determine the acidity of catalysts and catalyst carriers by ammonia chemisorption for materials specifications, manufacturing control, and research and development in the evaluation of catalysts.
SCOPE
1.1 This test method covers the determination of acidity of catalysts and catalyst carriers by ammonia chemisorption. A volumetric measuring system is used to obtain the amount of chemisorbed ammonia.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4824 − 13 (Reapproved 2018)
Standard Test Method for
Determination of Catalyst Acidity by Ammonia
Chemisorption
This standard is issued under the fixed designation D4824; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This test method involves the measurement of total catalyst acidity by chemisorption of ammonia
in a static volumetric system.Acidity is a very important property in determining catalyst activity and
selectivity in many commercial reactions. Zeolite based catalysts used in the petroleum industry for
catalytic cracking are a prime example. This test method describes a simple procedure employing
inexpensive equipment that could readily be assembled in most laboratories.
1. Scope Determine the Precision of a Test Method
1.1 This test method covers the determination of acidity of
3. Terminology
catalysts and catalyst carriers by ammonia chemisorption. A
volumetric measuring system is used to obtain the amount of
3.1 Definitions—See Terminology D3766.
chemisorbed ammonia.
3.2 Symbols:
1.2 The values stated in SI units are to be regarded as
standard. The values given in parentheses after SI units are
V = calibrated expansion volume, cm .
providedforinformationonlyandarenotconsideredstandard.
k
T = temperature of V at initial ammonia pressure, K.
1 k
1.3 This standard does not purport to address all of the
T = temperature of V at final ammonia pressure, K.
2 k
safety concerns, if any, associated with its use. It is the
P = initial ammonia pressure, torr.
responsibility of the user of this standard to establish appro-
P = final ammonia pressure, torr.
priate safety, health, and environmental practices and deter-
W = mass of sample, g.
s
mine the applicability of regulatory limitations prior to use.
W = tare of sample tube, g.
1.4 This international standard was developed in accor-
W = sample mass plus tare of tube, g.
dance with internationally recognized principles on standard- P = initial ammonia pressure corrected to standard
1T
ization established in the Decision on Principles for the
temperature, torr.
Development of International Standards, Guides and Recom- P = final ammonia pressure corrected to standard
2T
mendations issued by the World Trade Organization Technical temperature, torr.
Barriers to Trade (TBT) Committee.
4. Summary of Test Method
2. Referenced Documents
4.1 Asample is degassed by heating in a vacuum to remove
2.1 ASTM Standards:
adsorbed vapors from the surface. The sample is then exposed
D3766Terminology Relating to Catalysts and Catalysis
to an excess of gaseous ammonia and the excess ammonia is
E691Practice for Conducting an Interlaboratory Study to
removed by freezing it into a trap cooled with liquid nitrogen.
The chemisorbed ammonia is calculated as the difference
between the volume of ammonia before exposure and the
This test method is under the jurisdiction of ASTM Committee D32 on
volume recovered in the liquid nitrogen trap.
Catalysts and is the direct responsibility of Subcommittee D32.01 on Physical-
Chemical Properties.
Current edition approved Nov. 1, 2018. Published December 2018. Originally
5. Significance and Use
approved in 1988. Last previous edition approved in 2013 as D4824 –13. DOI:
10.1520/D4824-13R18.
5.1 This test method can be used to determine the acidity of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
catalysts and catalyst carriers by ammonia chemisorption for
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
materials specifications, manufacturing control, and research
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. and development in the evaluation of catalysts.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4824 − 13 (2018)
6. Apparatus 7. Reagents
6.1 Aschematic diagram of one type of apparatus is shown
7.1 Ammonia Gas, at least 99.9% pure.
in Fig. 1. It may be constructed of glass or metal and may
7.2 Liquid Nitrogen.
operate manually or automatically. It has the following fea-
tures: 7.3 Nitrogen Gas, at least 99.9% pure, passed through
6.1.1 Vacuum System, capable of attaining and maintaining drying tube.
−4
pressures below 10 torr (0.01 Pa) in the absence of catalyst.
6.1.2 Expansion Vessel, having a volume between 300 to 8. Procedure
3 3
500 cm (V ) known to the nearest 0.01 cm (Note 1). This
k
8.1 Weigh sample tubes to 0.1 mg and record as W . Place
volume is defined as the volume between stopcocks V and V
7 8
approximately2gof sample into the sample tube.
and includes the pressure gage and ammonia bulb.
8.2 Attach the sample tube to the apparatus.
NOTE 1—An expansion vessel of smaller volume is recommended for
materials of low surface area or smaller sample size.
8.3 Open the sample valves (V or V , or both).
5 6
6.1.3 Pressure Sensing Device or Pressure Transducer,
8.4 Slowly open the valve to the vacuum system (V ),
−1
capable of measuring 0 to 250 torr to the nearest 10 torr (10
monitoring the rate of pressure decrease to avoid too high a
Pa).
rate, which might lead to excessive fluidization of powdered
6.1.4 Pressure Sensing Device or Pressure Transducer,
samples.
−3
capableofmeasuring0to1000torrtothenearest10 torr(0.1
8.5 Place a heating mantle or furnace around each sample
Pa).
and raise the temperature to 673 K.
6.1.5 Valve, (V ) from ammonia supply to the expansion
volume.
NOTE 2—Take special precautions if the moisture content exceeds
6.1.6 Sample Tubes, with volume bet
...
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D4824 − 13 (Reapproved 2018)
Standard Test Method for
Determination of Catalyst Acidity by Ammonia
Chemisorption
This standard is issued under the fixed designation D4824; 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.
INTRODUCTION
This test method involves the measurement of total catalyst acidity by chemisorption of ammonia
in a static volumetric system. Acidity is a very important property in determining catalyst activity and
selectivity in many commercial reactions. Zeolite based catalysts used in the petroleum industry for
catalytic cracking are a prime example. This test method describes a simple procedure employing
inexpensive equipment that could readily be assembled in most laboratories.
1. Scope Determine the Precision of a Test Method
1.1 This test method covers the determination of acidity of
3. Terminology
catalysts and catalyst carriers by ammonia chemisorption. A
volumetric measuring system is used to obtain the amount of
3.1 Definitions—See Terminology D3766.
chemisorbed ammonia.
3.2 Symbols:
1.2 The values stated in SI units are to be regarded as
standard. The values given in parentheses after SI units are
V = calibrated expansion volume, cm .
provided for information only and are not considered standard. k
T = temperature of V at initial ammonia pressure, K.
1 k
1.3 This standard does not purport to address all of the
T = temperature of V at final ammonia pressure, K.
2 k
safety concerns, if any, associated with its use. It is the
P = initial ammonia pressure, torr.
responsibility of the user of this standard to establish appro-
P = final ammonia pressure, torr.
priate safety, health, and environmental practices and deter-
W = mass of sample, g.
s
mine the applicability of regulatory limitations prior to use.
W = tare of sample tube, g.
1.4 This international standard was developed in accor-
W = sample mass plus tare of tube, g.
dance with internationally recognized principles on standard-
P = initial ammonia pressure corrected to standard
1T
ization established in the Decision on Principles for the temperature, torr.
Development of International Standards, Guides and Recom- P = final ammonia pressure corrected to standard
2T
mendations issued by the World Trade Organization Technical temperature, torr.
Barriers to Trade (TBT) Committee.
4. Summary of Test Method
2. Referenced Documents
4.1 A sample is degassed by heating in a vacuum to remove
2.1 ASTM Standards:
adsorbed vapors from the surface. The sample is then exposed
D3766 Terminology Relating to Catalysts and Catalysis
to an excess of gaseous ammonia and the excess ammonia is
E691 Practice for Conducting an Interlaboratory Study to
removed by freezing it into a trap cooled with liquid nitrogen.
The chemisorbed ammonia is calculated as the difference
between the volume of ammonia before exposure and the
This test method is under the jurisdiction of ASTM Committee D32 on
volume recovered in the liquid nitrogen trap.
Catalysts and is the direct responsibility of Subcommittee D32.01 on Physical-
Chemical Properties.
Current edition approved Nov. 1, 2018. Published December 2018. Originally
5. Significance and Use
approved in 1988. Last previous edition approved in 2013 as D4824 – 13. DOI:
10.1520/D4824-13R18.
5.1 This test method can be used to determine the acidity of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
catalysts and catalyst carriers by ammonia chemisorption for
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
materials specifications, manufacturing control, and research
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. and development in the evaluation of catalysts.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4824 − 13 (2018)
6. Apparatus 7. Reagents
6.1 A schematic diagram of one type of apparatus is shown
7.1 Ammonia Gas, at least 99.9 % pure.
in Fig. 1. It may be constructed of glass or metal and may
7.2 Liquid Nitrogen.
operate manually or automatically. It has the following fea-
tures: 7.3 Nitrogen Gas, at least 99.9 % pure, passed through
6.1.1 Vacuum System, capable of attaining and maintaining drying tube.
−4
pressures below 10 torr (0.01 Pa) in the absence of catalyst.
6.1.2 Expansion Vessel, having a volume between 300 to
8. Procedure
3 3
500 cm (V ) known to the nearest 0.01 cm (Note 1). This
k
8.1 Weigh sample tubes to 0.1 mg and record as W . Place
volume is defined as the volume between stopcocks V and V
7 8
approximately 2 g of sample into the sample tube.
and includes the pressure gage and ammonia bulb.
8.2 Attach the sample tube to the apparatus.
NOTE 1—An expansion vessel of smaller volume is recommended for
materials of low surface area or smaller sample size.
8.3 Open the sample valves (V or V , or both).
5 6
6.1.3 Pressure Sensing Device or Pressure Transducer,
8.4 Slowly open the valve to the vacuum system (V ),
−1
capable of measuring 0 to 250 torr to the nearest 10 torr (10
monitoring the rate of pressure decrease to avoid too high a
Pa).
rate, which might lead to excessive fluidization of powdered
6.1.4 Pressure Sensing Device or Pressure Transducer,
samples.
−3
capable of measuring 0 to 1000 torr to the nearest 10 torr (0.1
8.5 Place a heating mantle or furnace around each sample
Pa).
and raise the temperature to 673 K.
6.1.5 Valve, (V ) from ammonia supply to the expansion
volume.
NOTE 2—Take special precautions if the moisture content exceeds
6.1.6 Sample Tubes, with volume between 5 and 25 cm .
approximately 5 % to avoid “bumping” of powdered sample. It is
The sample tube
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D4824 − 13 D4824 − 13 (Reapproved 2018)
Standard Test Method for
Determination of Catalyst Acidity by Ammonia
Chemisorption
This standard is issued under the fixed designation D4824; 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.
INTRODUCTION
This test method involves the measurement of total catalyst acidity by chemisorption of ammonia
in a static volumetric system. Acidity is a very important property in determining catalyst activity and
selectivity in many commercial reactions. Zeolite based catalysts used in the petroleum industry for
catalytic cracking are a prime example. This test method describes a simple procedure employing
inexpensive equipment that could readily be assembled in most laboratories.
1. Scope
1.1 This test method covers the determination of acidity of catalysts and catalyst carriers by ammonia chemisorption. A
volumetric measuring system is used to obtain the amount of chemisorbed ammonia.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.after
SI units are provided for information only and are not considered standard.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D3766 Terminology Relating to Catalysts and Catalysis
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions—See Terminology D3766.
3.2 Symbols:
V = calibrated expansion volume, cm .
k
T = temperature of V at initial ammonia pressure, K.
1 k
T = temperature of V at final ammonia pressure, K.
2 k
P = initial ammonia pressure, torr.
P = final ammonia pressure, torr.
W = mass of sample, g.
s
This test method is under the jurisdiction of ASTM Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.01 on Physical-Chemical
Properties.
Current edition approved April 1, 2013Nov. 1, 2018. Published August 2013December 2018. Originally approved in 1988. Last previous edition approved in 20082013
as D4824 – 03(2008).– 13. DOI: 10.1520/D4824-13.10.1520/D4824-13R18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4824 − 13 (2018)
W = tare of sample tube, g.
W = sample mass plus tare of tube, g.
P = initial ammonia pressure corrected to standard temperature, torr.
1T
P = final ammonia pressure corrected to standard temperature, torr.
2T
4. Summary of Test Method
4.1 A sample is degassed by heating in a vacuum to remove adsorbed vapors from the surface. The sample is then exposed to
an excess of gaseous ammonia and the excess ammonia is removed by freezing it into a trap cooled with liquid nitrogen. The
chemisorbed ammonia is calculated as the difference between the volume of ammonia before exposure and the volume recovered
in the liquid nitrogen trap.
5. Significance and Use
5.1 This test method can be used to determine the acidity of catalysts and catalyst carriers by ammonia chemisorption for
materials specifications, manufacturing control, and research and development in the evaluation of catalysts.
6. Apparatus
6.1 A schematic diagram of one type of apparatus is shown in Fig. 1. It may be constructed of glass or metal and may operate
manually or automatically. It has the following features:
−4
6.1.1 Vacuum System, capable of attaining and maintaining pressures below 10 torr (0.01 Pa) in the absence of catalyst.
3 3
6.1.2 Expansion Vessel, having a volume between 300 to 500 cm (V ) known to the nearest 0.01 cm (Note 1). This volume
k
is defined as the volume between stopcocks V and V and includes the pressure gage and ammonia bulb.
7 8
NOTE 1—An expansion vessel of smaller volume is recommended for materials of low surface area or smaller sample size.
−1
6.1.3 Pressure Sensing Device or Pressure Transducer, capable of measuring 0 to 250 torr to the nearest 10 torr (10 Pa).
−3
6.1.4 Pressure Sensing Device or Pressure Transducer, capable of measuring 0 to 1000 torr to the nearest 10 torr (0.1 Pa).
6.1.5 Valve, (V ) from ammonia supply to the expansion volume.
6.1.6 Sample Tubes, with volume between 5 and 25 cm . The sample tube(s) may be connected to the apparatus with standard
taper joints, glass-to-glass seals, or compression fittings.
6.1.7 Dewar Flask(s), for immersion of ammonia (freeze-back bulb) in liquid nitrogen.
6.1.8 Thermometer or Thermocouple, for measuring the temperature of the expansion volume, V . Alternatively, the expansion
k
volume may be thermostatted a few degrees above ambient to obviate the necessity of recording this temperature.
6.1.9 Heating Mantle or Small Furnace, for each sample tube.
6.1.10 Balance, with 0.1-mg sensitivity.
6.1.11 Thermometer or Thermocouple, for measuring the temperature of the sa
...
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