G74 催化剂基础标准与通用方法 标准查询与下载

ASTM D4513-97(2001)e1 筛分法测定催化材料的粒度分布的标准试验方法

1.1 This test method covers the determination of particle size distribution of catalytic powder material using a sieving instrument and is one of several found valuable for the measurement of particle size. This test method is particularly suitable for particles in the 20 to 420-956;m range. 1.2 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 applicability of regulatory limitations prior to use.

Standard Test Method for Particle Size Distribution of Catalytic Materials by Sieving

HG/T 2783-1996 分子筛抗压碎力试验方法

本标准规定了分子筛颗粒抗压碎力的试验方法。 本标准适用于各类分子筛颗粒抗压碎力的测定。

Molecular sieve crush resistance test method

HG/T 2782-1996 化肥催化剂颗粒抗压碎力的测定

Determination of resistance to crushing of fertilizer catalyst particles

HG/T 2780-1996 一氧化碳耐硫变换催化剂试验方法

本标准规定了一氧化碳耐硫变换催化剂产品的活性、点压抗压碎力、磨耗率、钴钼含量的测定和活性试验装置的校验。

Test method for carbon monoxide sulfur tolerant shift catalysts

HG/T 2781-1996 一氧化碳耐硫变换催化剂中钴钼含量的测定

本标准规定了B 301、B 301Q、B 302Q、B 303Q型等同系列一氧化碳耐硫变换催化剂中氧化钴和三氧化钼的测定方法。 本标准适用于以氧化钴、三氧化钼为活性组份的一氧化碳耐硫变换催化剂的组份测定。

Determination of Cobalt and Molybdenum Content in Carbon Monoxide Sulfur-tolerant Shift Catalyst

ASTM D4058-96 催化剂及其载体磨损的标准试验方法

1.1 This test method covers the determination of the attrition and abrasion resistance of catalysts and catalyst carriers. It is applicable to tablets, extrudate, spheres, and irregularly shaped particles larger than about 1/16 in. (1.6 mm) and smaller than about 3/4 in. (19 mm). The materials used in developing the method exhibited losses on attrition less than 7%; however, the method should be applicable to materials giving much higher attritions. 1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only. 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 and health practices and determine the applicability of regulatory limitations prior to use.

Standard Test Method for Attrition and Abrasion of Catalysts and Catalyst Carriers

ASTM D4463/D4463M-96(2013)e1 淡水分裂催化剂的金属自由蒸汽去活化作用的标准指南

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. 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 gt;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 ......

Standard Guide for Metals Free Steam Deactivation of Fresh Fluid Cracking Catalysts

ASTM D4463/D4463M-96(2012)e1 淡水分裂催化剂的金属自由蒸汽去活化作用的标准指南

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.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 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 stand......

Standard Guide for Metals Free Steam Deactivation of Fresh Fluid Cracking Catalysts

ASTM D4058-96(2011)e1 催化剂及载体磨耗性的标准试验方法

This test method is considered to be a measure of the propensity of a catalyst to produce fines in the course of transportation, handling, and use. However, there is no absolute level of acceptability. The values obtained are significant principally in relation to values for other materials (or other samples of the same material) of comparable size.1.1 This test method covers the determination of the attrition and abrasion resistance of catalysts and catalyst carriers. It is applicable to tablets, extrudate, spheres, and irregularly shaped particles larger than about 1/16 in. (1.6 mm) and smaller than about 3/4 in. (19 mm). The materials used in developing the method exhibited losses on attrition less than 7 %; however, the method should be applicable to materials giving much higher attritions. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that 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 and health practices and determine the applicability of regulatory limitations prior to use.

Standard Test Method for Attrition and Abrasion of Catalysts and Catalyst Carriers

ASTM D4058-96(2001) 催化剂及其载体磨损的标准试验方法

1.1 This test method covers the determination of the attrition and abrasion resistance of catalysts and catalyst carriers. It is applicable to tablets, extrudate, spheres, and irregularly shaped particles larger than about 1/16 in. (1.6 mm) and smaller than about 3/4 in. (19 mm). The materials used in developing the method exhibited losses on attrition less than 7%; however, the method should be applicable to materials giving much higher attritions. 1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only. 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 and health practices and determine the applicability of regulatory limitations prior to use.

Standard Test Method for Attrition and Abrasion of Catalysts and Catalyst Carriers

ASTM D4058-96(2006) 催化剂及其载体磨损的标准试验方法

This test method is considered to be a measure of the propensity of a catalyst to produce fines in the course of transportation, handling, and use. However, there is no absolute level of acceptability. The values obtained are significant principally in relation to values for other materials (or other samples of the same material) of comparable size.1.1 This test method covers the determination of the attrition and abrasion resistance of catalysts and catalyst carriers. It is applicable to tablets, extrudate, spheres, and irregularly shaped particles larger than about 1/16 in. (1.6 mm) and smaller than about 3/4 in. (19 mm). The materials used in developing the method exhibited losses on attrition less than 7 %; however, the method should be applicable to materials giving much higher attritions.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.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 applicability of regulatory limitations prior to use.

Standard Test Method for Attrition and Abrasion of Catalysts and Catalyst Carriers

ASTM D4463-96(2006) 淡水分裂催化剂的金属自由蒸汽去活化作用标准指南

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.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 an......

Standard Guide for Metals Free Steam Deactivation of Fresh Fluid Cracking Catalysts

ASTM D4463-96(2001) 淡水分裂催化剂的金属自由蒸汽去活化作用标准指南

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 and/or operating conditions, 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 performance 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) and selectivities.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 standard. The values given in parentheses are provided 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 applicability of regulatory limitations prior to use.

Standard Guide for Metals Free Steam Deactivation of Fresh Fluid Cracking Catalysts

ASTM D4463-96 淡水分裂催化剂的金属自由蒸汽去活化作用标准指南

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 and/or operating conditions, 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 performance 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) and selectivities.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 standard. The values given in parentheses are provided 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 applicability of regulatory limitations prior to use.

Standard Guide for Metals Free Steam Deactivation of Fresh Fluid Cracking Catalysts

SH/T 0625-1995 硅铝催化剂中γ-Al₂O₃含量测定法（X射线衍射法）

Determination of γ-Al₂O₃ content in silicon-alumina catalyst (X-ray diffraction method)

HG/T 2693-1995 一氧化碳高温变换催化剂化学成份的测定

本标准规定了B 107、B 107-1、B 108、B 109、B 110-2、B 111、B 112、B 113、B 114、115、B 116、B 117、B 118、B 119型等一氧化碳高温变换催化剂的主要化学成份的分析方法。 本标准适用于高变催化剂中铁、铬、氧化钾、总钼、本体硫和烧失量等化学成份的测定。

Determination of Chemical Composition of Carbon Monoxide High Temperature Shift Catalyst

ASTM D4780-95(2007) 用多点氪吸附法测定催化剂的低表面面积的标准试验方法

This test method has been found useful for the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m2/g for materials specification, manufacturing control, and research and development in the evaluation of catalysts. The determination of surface area of catalysts and catalyst carriers above 10 m2/g is addressed in Test Method D 3663.1.1 This test method covers the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m2/g. A volumetric measuring system is used to obtain at least three data points which fall within the linear BET region.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.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 applicability of regulatory limitations prior to use.

Standard Test Method for Determination of Low Surface Area of Catalysts by Multipoint Krypton Adsorption

ASTM D4780-95 用多点氪吸附法测定催化剂的低表面面积的标准试验方法

1.1 This test method covers the determination of the specific surface area of catalysts and catalyst carriers in the range from 0.05 to 10 m/g. A volumetric measuring system is used to obtain at least three data points which fall within the linear BET region. 1.2 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 applicability of regulatory limitations prior to use.

Standard Test Method for Determination of Low Surface Area of Catalysts by Multipoint Krypton Adsorption

ASTM D4365-95(2008) 测定催化剂微孔体积和沸石面积的标准试验方法

This gas adsorption method complements the X-ray procedure of Test Method D 3906. This test method will be useful to laboratories that do not have X-ray diffractometers. Each test method can be calibrated by use of an appropriate series of mechanical mixtures to provide what may be termed percent zeolite. If there is disorder in the zeolite, the adsorption method will yield higher values than the X-ray method. The reverse will be true if some zeolite pores (micropores) are blocked or filled.1.1 This test method covers the determination of total surface area and mesopore area. From these results are calculated the zeolite area and micropore volume of a zeolite containing catalyst. The micropore volume is related to the percent zeolite in the catalyst. The zeolite area, a number related to the surface area within the zeolite pores, may also be calculated. Zeolite area, however, is difficult to intepret in physical terms because of the manner in which nitrogen molecules pack within the zeolite. 1.2 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 applicability of regulatory limitations prior to use. For a specific precautionary statement, see Note 3.

Standard Test Method for Determining Micropore Volume and Zeolite Area of a Catalyst

ASTM D4641-94(2006) 由氮解吸等温线计算催化剂孔隙尺寸分布的标准实施规程

Pore volume distribution curves obtained from nitrogen sorption isotherms provide one of the best means of characterizing the pore structure in porous catalysts, provided that the limitations of the method are kept in mind. Used in conjunction with the BET treatment for surface area determination (4), these methods provide an indispensable means for studying the structure associated with pores usually important in catalysts. This practice is particularly useful in studying changes in a series of closely related samples caused by treatments, such as heat, compression, or extrusion often used in catalyst manufacturing. Pore volume distribution curves can often provide valuable information during mechanistic studies dealing with catalyst deactivation.1.1 This practice covers the calculation of pore size distributions for catalysts and catalyst carriers from nitrogen desorption isotherms. The computational procedure is particularly useful for determining how the pore volume is distributed in catalyst samples containing pores whose sizes range from approximately 1.5 to 100 nm (15 to 1000 ) in radius. It should be used with caution when applied to isotherms for samples containing pores both within this size range and pores larger than 100 nm (1000 ) in radius. In such instances the isotherms rise steeply near P/Po = 1 and the total pore volume cannot be well defined. The calculations should be begun at a point on the isotherm near saturation preferably in a region near P/Po = 0.99, establishing an upper limit on the pore size distribution range to be studied. Simplifications are necessary regarding pore shape. A cylindrical pore model is assumed, and the method treats the pores as non-intersecting, open-ended capillaries which are assumed to function independently of each other during the adsorption or desorption of nitrogen. Note 1 - This practice is designed primarily for manual computation and a few simplifications have been made for this purpose. For computer computation, the simplified expressions may be replaced by exact expressions.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 applicability of regulatory limitations prior to use.

Standard Practice for Calculation of Pore Size Distributions of Catalysts from Nitrogen Desorption Isotherms