CEN/TS 14918:2005

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents
6 Apparatus
7 Preparation of test sample
8 Calorimetric procedure
9 Calibration
10 Gross calorific value
11 Precision
12 Calculation of net calorific value at constant pressure
13 Test report
Annex A (normative) Adiabatic bomb calorimeters
Annex B (normative) Isoperibol and static-jacket bomb
                      calorimeters
Annex C (normative) Automated bomb calorimeters
Annex D (informative) Checklists for the design and procedures
                      of combustion experiments
Annex E (informative) Examples to illustrate the main
                      calculations used in this Technical
                      Specification when an automated
                      (adiabatic) bomb calorimeter is used
                      for determinations
Annex F (informative) List of symbols used in this Technical
                      Specification
Annex G (informative) Key-word index
Annex H (informative) Default values of most used biofuels for
                      the calculations of calorific values
Annex I (informative) Flow chart for a routine calorific value
                      determination

This Technical Specification specifies a method for the determination of the gross calorific value of a solid biofuel at constant volume and at the reference temperature 25 °C in a bomb calorimeter calibrated by combustion of certified benzoic acid.The result obtained is the gross calorific value of the analysis sample at constant volume with all the water of the combustion products as liquid water. In practice, biofuels are burned at constant (atmospheric) pressure and the water is either not condensed (removed as vapour with the flue gases) or condensed. Under both conditions, the operative heat of combustion to be used is the net calorific value of the fuel at constant pressure. The net calorific value at constant volume may also be used; formulae are given for calculating both values.General principles and procedures for the calibrations and the biofuel experiments are presented in the main text, whereas those pertaining to the use of a particular type of calorimetric instrument are described in annexes A to C. Annex D contains checklists for performing calibration and fuel experiments using specified types of calorimeters. Annex E gives examples to illustrate some of the calculations.