ISO INTERNATIONAL STANDARD 21654 First edition 2021-06 Solid recovered fuels Determination of calorific value Combustibles solides de reécupération - Détermination du pouvoir calorifique Reference number ISO 21654:2021(E) ISO IS02021 IS0 21654:2021(E) COPYRIGHT PROTECTED DOCUMENT @ iS0 2021 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 0111 Email: [email protected] Website: www.iso.org Published in Switzerland i @ IS0 2021 - All rights reserved IS0 21654:2021(E) Contents Page Foreword .V Introduction. ..vi 1 Scope. .1 2 Normative references. .1 3 Terms and definitions .1 4 Principle .2 4.1 Gross calorific value 2 4.2 Net calorific value. .3 5 Reagents .3 6 Laboratory conditions .4 7 Apparatus. .5 7.1 General 5 7.2 Auxiliary equipment 7 7.3 Balances .7 8 Preparation of test sample .8 9 Calorimetric procedure .8 9.1 General .8 9.2 Preparing the combustion vessel for measurement 9 9.2.1 General procedure. 9 9.2.2 Using combustion aids. .10 9.3 Assembling the calorimeter. .11 9.4 Combustion reaction and temperature measurements 11 9.5 Analysis of products of combustion 12 9.6 Corrected temperature rise 12 9.6.1 Observed temperature rise 12 9.6.2 Isoperibol and static-jacket calorimeters. 12 9.6.3 Adiabatic calorimeters ..14 9.6.4 Thermometer corrections .14 9.7 Reference temperature 14 10 Calibration .14 10.1 Principle .14 10.2 Calibrationreference 15 10.2.1 Certification conditions. .15 10.2.2 Calibration conditions. .15 10.3 Valid working range of the effective heat capacity 15 10.4 Ancillarycontributions 16 10.5 Calibration procedure. 16 10.6 Calculation of effective heat capacity for the individual experiment 17 10.6.1 Constant mass-of-calorimeter-water basis. 17 10.6.2 Constant total-calorimeter-mass basis. 17 10.7 Precision of the mean value of the effective heat capacity ..18 10.7.1 Constant value of ε ..18 10.7.2 as a function of the observed temperature rise .19 10.8 Repetition of the determination of effective heat capacity .19 11 Gross calorific value ..19 11.1 General .19 11.2 Combustion 20 11.3 Calculation of gross calorific value 20 @ IS0 2021 - All rights reserved ii IS0 21654:2021(E) 11.3.1 General. 20 11.3.2 Constant mass-of-calorimeter-water basis 20 11.3.3 Constanttotal-calorimeter-massbasis .22 11.3.4 as a function of the observed temperature rise. .23 11.4 Expression of results. 23 11.5 Calculation to other bases .23 12 Precision .24 12.1 Repeatability limit. .24 12.2 Reproducibility limit .24 13 Calculation of net calorific value at constant pressure .24 13.1 General .24 13.2 Calculations .24 14 Test report. ..25 Annex A (normative) Adiabatic combustion vessel calorimeters .27 Annex B (normative) Isoperibol and static-jacket combustion vessel calorimeters .31 Annex C (normative) Automated combustion vessel calorimeters .36 Annex D (normative) Removed ash contributors ..39 Annex E (informative) Checklists for the design and procedures of combustion experiments.. ..42 Annex F (informative) Examples to illustrate the main calculations used in this document if an automated (adiabatic) combustion vessel calorimeter is used for determinations ..47 Annex G (informative) List of symbols used in this document. .50 Annex H (informative) Flow chart for a routine calorific value determination ..53 Annex I (informative) Interlaboratory test results. .54 Annex J (informative) Additional terms for the basis of results expression .57 Annex K (informative) Environmental aspects .58 Bibliography .60 iv @ IS0 2021 - All rights reserved IS0 21