ASTM_D_7206_-_D_7206M_-_19.pdf

Designation:D7206/D7206M19Standard Guide forCyclic Deactivation of Fluid Catalytic Cracking(FCC)Catalysts with Metals1This standard is issued under the fixed designation D7206/D7206M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide covers the deactivation of fluid catalyticcracking(FCC)catalyst in the laboratory as a precursor tosmall scale performance testing such as catalyst activities(TestMethod D3907)or activities plus selectivities(Test MethodsD5154 and D7964).FCC catalysts are deactivated in thelaboratory in order to simulate the aging that occurs duringcontinuous use in a commercial fluid catalytic cracking unit(FCCU).Deactivation for purposes of this guide constituteshydrothermal deactivation of the catalyst and metal poisoningby nickel and vanadium.Hydrothermal treatment is used tosimulate the physical changes that occur in the FCC catalystthrough repeated regeneration cycles.Hydrothermal treatment(steaming)destabilizes the faujasite(zeolite Y),resulting inreduced crystallinity and surface area.Further decompositionof the crystalline structure occurs in the presence of vanadium,and to a lesser extent in the presence of nickel.Vanadium isbelieved to form vanadic acid in a hydrothermal environmentresulting in destruction of the zeolitic portion of the catalyst.Nickels principle effect is to poison the selectivity of the FCCcatalyst.Hydrogen and coke production is increased in thepresence of nickel,due to the dehydrogenation activity of themetal.Vanadium also exhibits significant dehydrogenationactivity,the degree of which can be influenced by the oxidationand reduction conditions prevailing throughout the deactiva-tion process.The simulation of the metal effects that one wouldsee commercially is part of the objective of deactivatingcatalysts in the laboratory.Catalyst deactivation by hydrother-mal treatment only is addressed in Guide D4463/D4463M.1.2 The two basic approaches to laboratory-scale simulationof commercial equilibrium catalysts described in this guide areas follows:1.2.1 Cyclic Propylene Steaming(CPS)Method,in whichthe catalyst is impregnated with the desired metals via anincipient wetness procedure(Mitchell method)2followed by aprescribed steam deactivation.1.2.2 Crack-on Methods,in which fresh catalyst is subjectedto a repetitive sequence of cracking(using a feed withenhanced metals concentrations),stripping,and regeneration inthe presence of steam.Two specific procedures are presentedhere,a procedure with alternating metal deposition and deac-tivation steps and a modified Two-Step procedure,whichincludes a cyclic deactivation process to target lower vanadiumdehydrogenation activity.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are not necessarily exact equivalents;therefore,toensure conformance with the standard,each system shall beused independently of the other,and values from the twosystems shall not be combined.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3D3907 Test Method for Testing Fluid Catalytic Cracking(FCC)Catalysts by Microactivity TestD4463/D4463M Guide for Metals Free Steam Deactivation1This guide is under the jurisdiction of ASTM Committee D32 on Catalysts andis the direct responsibility of Subcommittee D32.04 on Catalytic Properties.Current edition approved April 1,2019.Published April 2019.Originallyapproved in 2006.Last previous edition approved in 2013 as D7206/D7206M06(2013)1.DOI:10.1520/D7206_D7206M-19.2Mitchell,B.R.,Industrial and Engineering Chemistry Product Research andDevelopment,19,1980,p.209.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of Inte