1、Designation: D5865 12Standard Test Method forGross Calorific Value of Coal and Coke1This standard is issued under the fixed designation D5865; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in p
2、arentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method pertains to the determination of thegross calorific value of coal and coke by either an isoperibol oradiabatic bomb calorimeter.
3、1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 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 appr
4、o-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardstatements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2D121 Terminology of Coal and CokeD346 Practice for Collection and Preparation of CokeSamples for L
5、aboratory AnalysisD388 Classification of Coals by RankD1193 Specification for Reagent WaterD2013 Practice for Preparing Coal Samples for AnalysisD3173 Test Method for Moisture in the Analysis Sample ofCoal and CokeD3177 Test Methods for Total Sulfur in theAnalysis Sampleof Coal and CokeD3180 Practic
6、e for Calculating Coal and Coke Analysesfrom As-Determined to Different BasesD4239 Test Method for Sulfur in the Analysis Sample ofCoal and Coke Using High-Temperature Tube FurnaceCombustionD7582 Test Methods for Proximate Analysis of Coal andCoke by Macro Thermogravimetric AnalysisE144 Practice for
7、 Safe Use of Oxygen Combustion BombsE178 Practice for Dealing With Outlying ObservationsE882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE2251 Specification for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision Liquids3. Terminology3.1 For additional def
8、initions of terms used in this testmethod, refer to Terminology D121.3.2 Definitions:3.2.1 adiabatic calorimetera calorimeter that operates inthe adiabatic mode and may or may not use a microprocessor.The initial temperature before initiating the combustion and thefinal temperatures are recorded by
9、the operator or the micro-processor.3.2.2 automated calorimetera calorimeter which has amicroprocessor that takes the thermometric readings and cal-culates the Calibration Value and the Heat of CombustionValues.3.2.3 British thermal unit Btuis the amount of heatrequired to raise the temperature of o
10、ne pound - mass lbm ofliquid water at one atmosphere pressure one degree Fahrenheitat a stated temperature. The results of combustion calorimetrictests of fuels for steam power plants may be expressed in termsof the 1956 International Steam Table calorie (I.T. cal) whichis defined by the relation, 1
11、 I.T. cal = 4.1868 J. The Btu usedin modern steam tables is defined by the means of the relation,1I.T.cal/g=1.8I.T.Btu/lb.Thus, 1 I.T. Btu / lb = 2.326 J/g.3.2.4 calorific valuethe heat produced by combustion of aunit quantity of a substance under specified conditions.3.2.5 calorimetera device for m
12、easuring calorific valueconsisting of a bomb, its contents, a vessel for holding thebomb, temperature measuring devices, ignition leads, water,stirrer, and a jacket maintained at specified temperature con-ditions.3.2.6 gross calorific value (gross heat of combustion atconstant volume), Qv(gross)the
13、heat produced by completecombustion of a substance at constant volume with all waterformed condensed to a liquid.1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.21 on Methods ofAnalysis.Current edition approved Se
14、pt. 1, 2012. Published November 2012. Originallyapproved in 1995. Last previous edition approved in 2011 as D5865 11a. DOI:10.1520/D5865-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volum
15、e information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.7 heat of formationthe change in heat
16、content result-ing from the formation of 1 mole of a substance from itselements at constant pressure.3.2.8 isoperibol calorimetera calorimeter that operates inthe isoperibol mode and uses a microprocssor to record theinitial and final temperatures and make the appropiate heat leakcorrections during
17、the temperature rise. It determines when thecalorimeter is in equilibrium and ignites the sample anddetermines when the calorimeter has reached equilibrium afterignition.3.2.9 net calorific value (net heat of combustion at constantpressure), Qp(net)the heat produced by combustion of asubstance at a
18、constant pressure of 0.1 MPa (1 atm), with anywater formed remaining as vapor.3.3 Definitions of Terms Specific to This Standard:3.3.1 corrected temperature risethe calorimeter tempera-ture change caused by the process that occurs inside the bombcorrected for various effects.3.3.2 heat capacitythe e
19、nergy required to raise the tem-perature of the calorimeter one arbitrary unit.3.3.2.1 DiscussionThe heat capacity can also be referredto as the energy equivalent or water equivalent of the calorim-eter.4. Summary of Test Method4.1 The heat capacity of the calorimeter is determined byburning a speci
20、fied mass of benzoic acid in oxygen. Acomparable amount of the analysis sample is burned under thesame conditions in the calorimeter. The calorific value of theanalysis sample is computed by multiplying the correctedtemperature rise, adjusted for extraneous heat effects, by theheat capacity and divi
21、ding by the mass of the sample.4.2 Oxidation of coal after sampling can result in a reduc-tion of calorific value. In particular, lignite and sub-bituminousrank coal samples may experience greater oxidation effectsthan samples of higher rank coals. Unnecessary exposure of thesamples to the air for t
22、he time of sampling or delay in analysisshall be avoided. (See X2.1.)5. Significance and Use5.1 The gross calorific value can be used to compute thetotal calorific content of the quantity of coal or coke repre-sented by the sample for payment purposes.5.2 The gross calorific value can be used for co
23、mputing thecalorific value versus sulfur content to determine whether thecoal meets regulatory requirements for industrial fuels.5.3 The gross calorific value can be used to evaluate theeffectiveness of beneficiation processes.5.4 The gross calorific value can be required to classifycoals according
24、to Classification D388.6. Apparatus and Facilities6.1 Test AreaAn area free from drafts, shielded fromdirect sunlight and other radiation sources. Thermostatic con-trol of room temperature and controlled relative humidity aredesirable.6.2 Combustion BombConstructed of materials that arenot affected
25、by the combustion process or the products formedto introduce measurable heat input or alteration of end prod-ucts. The bomb shall be designed so that all liquid combustionproducts can be completely recovered by washing the innersurfaces. There shall be no gas leakage. The bomb shall becapable of wit
26、hstanding a hydrostatic pressure test to 20 MPa(3000 psig) at room temperature without stressing any partbeyond its specified elastic limit.6.3 BalanceA laboratory balance capable of weighing theanalysis sample to the nearest 0.0001 g. The balance shall bechecked weekly, at a minimum, for accuracy.6
27、.4 Calorimeter VesselMade of metal with a tarnish-resistant coating, with all outer surfaces highly polished. Itssize shall be such that the bomb is completely immersed inwater during a determination. A stirrer shall be provided foruniform mixing of the water. The immersed portion of thestirrer shal
28、l be accessible to the outside through a coupler oflow thermal conductivity. The stirrer speed shall remainconstant to minimize any temperature variations due to stirring.Continuous stirring for 10 min shall not raise the calorimetertemperature more than 0.01C when starting with identicaltemperature
29、s in the calorimeter, test area and jacket. Forcalorimeters having a bucket it can be a separate component orintegral component of the bomb. The vessel shall be of suchconstruction that the environment of the calorimeters entireouter boundaries can be maintained at a uniform temperature.6.5 JacketAc
30、ontainer with the inner perimeter maintainedat constant temperature 60.1C (isoperibol) or at the sametemperature 60.1C as the calorimeter vessel (adiabatic)during the test. To minimize convection, the sides, top andbottom of the calorimeter vessel shall not be more than 10 mmfrom the inner surface o
31、f the jacket. Mechanical supports forthe calorimeter vessel shall be of low thermal conductivity.6.6 Thermometers:6.6.1 Platinum resistance or thermistor thermometersshall be capable of measuring to the nearest 0.0001C. Thesetypes of thermometers consist of two major subsystems. Thefirst and most ob
32、vious is the temperature sensing probe itself.The second and equally important aspect is the measurementsubsystem. For both subsystems, the relationship between thethermometer resistance and temperature shall be well charac-terized. The absolute temperature shall be known to 6 0.1Catthe temperature
33、of the calorimetric measurement.6.6.2 Assessing the valid working range of the calorimeter,as outlined in 10.9, is sufficient to demonstrate that allimportant aspects of the calorimeter functionality, includingthe thermometry, are in good working order. The traceability ofthe heat of combustion meas
34、urement is governed by thetraceability of the heat of combustion of the benzoic acidcalibrant in addition to meeting the aforementioned criteria.6.6.3 Liquid-in-Glass ThermometersConforming to therequirements for thermometers S56C, S116C, or S117C asprescribed in Specification E2251.D5865 1226.6.3.1
35、 Thermometer AccessoriesA magnifier is requiredfor reading liquid-in-glass thermometers to one tenth of thesmallest scale division. The magnifier shall have a lens andholder designed so as to minimize errors as a result of parallax.6.7 Sample HolderAn open crucible of platinum, quartz,or base metal
36、alloy. Before use in the calorimeter, heat treatbase metal crucibles for a minimum of4hat500C to ensurethe crucible surface is completely oxidized. Base metal alloycrucibles are acceptable, if after three preliminary firings, theweight does not change by more than 0.0001 g.6.8 Ignition FuseIgnition
37、fuse of 100-mm length and0.16-mm (No. 34 B filling the calorimeter vessel; firing theignition circuit; recording calorimeter temperatures before,during, and after the test; recording the balance weights; andcarrying out all necessary corrections and calculations.6.11 Crucible LinerQuartz fiber or al
38、undum for lining thecrucible to promote complete combustion of samples that donot burn completely during the determination of the calorificvalue.37. Reagents7.1 Reagent WaterConforming to conductivity require-ments for Type II of Specification D1193 for preparation ofreagents and washing of the bomb
39、 interior.7.2 Purity of ReagentsUse reagent grade chemicals con-forming to the specification of the Committee on AnalyticalReagents of the American Chemical Society in all tests.47.3 Benzoic AcidStandard (C6H5COOH)Pellets madefrom benzoic acid available from the National Institute ofStandards and Te
40、chnology (NIST) or benzoic acid calibratedagainst NIST standard material. The calorific value of benzoicacid, for use in the calibration calculations, shall be traceable toa recognized certificate value.7.4 OxygenManufactured from liquid air, guaranteed tobe greater than 99.5 % pure, and free of com
41、bustible matter.Oxygen made by the electrolytic process contains smallamounts of hydrogen rendering it unfit unless purified bypassage over copper oxide at 500C.7.5 Titration IndicatorMethyl orange, methyl red, ormethyl purple for indicating the end point when titrating theacid formed during combust
42、ion. The same indicator shall beused for both calibration and calorific value determinations.7.6 Standard SolutionSodium carbonate (Na2CO3)orother suitable standard solution.Aconvenient standard solutionmay be prepared as follows. Dissolve 3.706 g of sodiumcarbonate, dried for 24 h at 105C, in water
43、 and dilute to 1 L.The resulting concentration (0.0699 N) assumes the energy offormation of HNO3under bomb conditions is -59.7 kJ/mol(-14.3 kcal/mole) (seeX1.1). One milliliter of this solution isequivalent to 4.2 J (1.0 cal) in the acid titration. Alternatively,1.0 ml of a 0.1000 N base solution is
44、 equivalent to 6.0 J (1.4cal) in the acid titration. In general, one milliliter of an arbitrarystandard titrant solution is equivalent to its concentration(equivalents / liter or normality N) times 59.7 J (14.3 cal).8. Hazards8.1 The following precautions are recommended for safecalorimeter operatio
45、n. Additional precautions are noted inPractice E144. Also consult the calorimeter equipment manu-facturers installation and operating instructions before usingthe calorimeter.8.1.1 The mass of sample and any combustion aid as well asthe pressure of the oxygen admitted to the bomb shall notexceed the
46、 bomb manufacturers specifications.8.1.2 Inspect the bomb parts carefully after each use.Replace cracked or significantly worn parts. Replace O-ringsand valve seats in accordance with manufacturers instruction.For more details, consult the manufacturer.8.1.3 Equip the oxygen supply cylinder with an
47、approvedtype of safety device, such as a relief valve, in addition to theneedle valve and pressure gauge used in regulating the oxygenfeed to the bomb. Valves, gauges, and gaskets shall meetindustry safety codes. Suitable reducing valves and adaptersfor 3- to 4-MPa (300- to 500-psig) discharge press
48、ure can beobtained from commercial sources of compressed gas equip-ment. Check the pressure gauge annually for accuracy or afterany accidental over pressures that reach maximum gaugepressure.8.1.4 During ignition of a sample, the operator shall notextend any portion of the body over the calorimeter.
49、8.1.5 Do not fire the bomb if the bomb has been dropped orturned over after loading.8.1.6 Do not fire the bomb if there is evidence of gasleakage when the bomb is submerged in the calorimeter vessel.8.1.7 For manually operated calorimeters, the ignitionswitch shall be depressed only long enough to fire the charge.9. Sample9.1 The analysis sample is the material pulverized to pass250-m (No. 60) sieve, prepared in accordance with eitherPractice D346 for coke or Method D2013 for coal.3Supporting data have been filed at ASTM International
