Due to the commercial transfer of billions of cubic meters of natural gases, the knowledge of the gross calorific value (GCV) of the main natural gas components and, in particular, of methane, is of outstanding interest. On the basis of previous work carried out by a Groupe Européen de Recherches Gazières (GERG)–Physikalisch-Technische Bundesanstalt collaboration, the so-called GERG calorimeter was further developed on the hardware as well as on the software side. With the renewed GERG calorimeter, the GCV of CH4 could be determined with unprecedented precision and accuracy. Important elements for improving the measuring methodology of flame calorimetry included the in situ calibration of the mass of the burned gas, the determination of the actual exhaust gas temperatures, and the detection of the water input by countercurrent water absorption from ambient air. For the first time, it was possible to determine the GCV not only via direct online weighing of the mass of burned gas but also via the stoichiometric water balance with a consistency of about 3.5 ppm. Based on 27 weighings of the mass of burned gas, the real-gas GCV of methane is determined as Hs(CH4) = 890 202.1 J mol−1 with a confidence interval of ±52.6 J mol−1(t95%= 2.056). This value is by ΔHs/Hs= (−0.0436 ± 0.0059)% below the real-gas GCV of Hs(CH4) = (890 590 ± 380) J mol−1 (k = 2) converted according to ISO 6976:2016. The difference can be explained by systematic influences as well as by failures in the stoichiometric water balance in all other measurements.

1.
EN ISO 6976
,
Natural Gas, Calculation of Calorific Values, Density, Relative Density and Wobbe Indices from Composition
(ISO 6976:2016) (
ISO
,
Geneva
,
2016
).
2.
F. D.
Rossini
,
Bur. Stand. J. Res.
6
,
37
(
1931
).
3.
D. A.
Pittam
and
G.
Pilcher
,
J. Chem. Soc. Faraday Trans. I
68
,
2224
(
1972
).
4.
M.
Jaeschke
,
A.
Schmücker
,
A.
Pramann
, and
P.
Ulbig
,
Int. J. Thermophys.
28
,
220
(
2007
).
5.
J.
Rauch
,
S. M.
Sarge
,
F.
Haloua
,
B.
Hay
,
J.-R.
Filtz
,
P.
Schley
,
M.
Beck
,
J. N.
Ponsard
,
O.
Gorieu
,
A.
Benito
, and
P. L.
Cremonesi
, “
GERG project: Development and setup of a new reference calorimeter, phase 2: Measurements on pure gases
,” in
Proceedings of International Gas Research Conference
,
Paris
,
2008
.
6.
P.
Schley
,
M.
Beck
,
M.
Uhrig
,
S. M.
Sarge
,
J.
Rauch
,
F.
Haloua
,
J.-R.
Filtz
,
B.
Hay
,
M.
Yakoubi
,
J.
Escande
,
A.
Benito
, and
P. L.
Cremonesi
,
Int. J. Thermophys.
31
,
665
(
2010
).
7.
ISO 6976
,
Natural Gas, Calculation of Calorific Values, Density, Relative Density and Wobbe Indices from Composition
(
ISO
,
Geneva
,
1995
).
8.
A.
Pramann
,
Development of a Reference Gas Calorimeter
, Final Internal Report,
PTB Braunschweig
,
Germany
,
2005
(personal communication by P. Schley of the GERG-group, 2010).
9.
F.
Haloua
,
E.
Foulon
,
A.
Allard
,
B.
Hay
, and
J. R.
Filtz
,
Metrologia
52
,
741
(
2015
).
10.
EURAMET cg–18, Version 3.0 (March 2011),
Braunschweig
,
Germany
,
2011
).
11.
H.
Preston-Thomas
,
Metrologia
27
,
3
(
1990
).
12.
S. M.
Sarge
, “
G2i_GERG_Referenzkalorimeter.llb (5-6-2010), Labview 7.0 program including execution scripts for controlling a calibration or combustion run
” (personal communication,
PTB Braunschweig
,
Germany
,
2010
).
13.
N.
Kurzeja
(Lehrstuhl für Thermodynamik, Ruhr-Universität Bochum, Germany) Evaluation spreadsheets Diagramm-07.9.8.5_05.xls (2014), DeltaTad-18.6.6.xls (2018) and Brennwert-08.3.0.xls (2019), as extended and revised versions of the original Excel spreadsheets Diagramm-06a.xls (December 14, 2009), DeltaTad-18e.xls (December 14, 2009) and BrennWert-06c.xls (December 7, 2009), written by
S. M.
Sarge
, PTB Braunschweig Germany (2009) in the framework of the GERG project: Development and Set-up of a new Reference Calorimeter.
14.
S. M.
Sarge
, Evaluation Excel spreadsheets Diagramm-06a.xls (December 14, 2009), DeltaTad-18e.xls (December 14, 2009) and BrennWert-06c.xls (December 7, 2009) (personal communication,
PTB Braunschweig
,
Germany
,
2010
).
15.
S. M.
Sarge
, “
Algorithmus zur Bestimmung des Brennwerts eines Gases mittels eines isoperibolen Verbrennungskalorimeters mit atmosphärischem Brenner
,” Version 1.5a, Stand: 16.09.2010 Variante 3: Off-line Thermistor-Kalibrierung, simultane exponentielle Regression, Simpson-Integration, Gleichung-05a - 2010-10-25.pdf (personal communication,
PTB Braunschweig
,
Germany
,
2010
).
16.
U.
Setzmann
and
W.
Wagner
,
J. Phys. Chem. Ref. Data
20
,
1061
(
1991
).
17.
R.
Schmidt
and
W.
Wagner
,
Fluid Phase Equilib.
19
,
175
(
1985
).
18.
R.
Span
and
W.
Wagner
,
J. Phys. Chem. Ref. Data
25
,
1509
(
1996
).
19.
W.
Wagner
and
A.
Pruß
,
J. Phys. Chem. Ref. Data
31
,
387
(
2002
).
20.
Ch.
Tegeler
,
R.
Span
, and
W.
Wagner
,
J. Phys. Chem. Ref. Data
28
,
779
(
1999
).
21.
E. W.
Lemmon
and
R.
Span
,
J. Chem. Eng. Data
51
,
785
(
2006
).
22.
W.
Wagner
,
U.
Overhoff
, and
N.
Kurzeja
,
Software FLUIDCAL
(V2.0.1.3) (
Lehrstuhl für Thermodynamik, Ruhr-Universität Bochum
,
Bochum, Germany
,
2017
).
23.
E. W.
Lemmon
,
I. H.
Bell
,
M. L.
Huber
, and
M. O.
McLinden
,
NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties-REFPROP
, Version 10 (
National Institute of Standards and Technology
,
Gaithersburg, USA
,
2018
).
24.
R.
Span
,
R.
Beckmüller
,
T.
Eckermann
,
S.
Herrig
,
S.
Hielscher
,
A.
Jäger
,
E.
Mickoleit
,
T.
Neumann
,
S. M.
Pohl
,
B.
Semrau
, and
M.
Thol
,
TREND, Thermodynamic Reference and Engineering Data 4.0
(
Lehrstuhl für Thermodynamik, Ruhr-Universität Bochum
,
Bochum, Germany
,
2019
).
25.
S. M.
Sarge
, “
Piping plan of the GERG-calorimeter
” (personal communication,
PTB Braunschweig
,
Germany
,
2019
).
26.
A.
Picard
,
R. S.
Davis
,
M.
Gläser
, and
K.
Fujii
,
Metrologia
45
,
149
(
2008
).
27.
Calibration certificate DKD-K-11801/14-05, G1–143 for No. K141036 and G1–144 for No. K141037 (Calibration Laboratory DKD-K-11801 Kern & Sohn, Germany, May 13, 2014).
28.
JCGM 100:2008
, GUM 1995 with Minor Corrections, Evaluation of Measurement Data—Guide to the Expression of Uncertainty in Measurement,
Geneva
,
2008
.
29.
ISO 14912:2003
,
Gas Analysis: Conversion of Gas Mixture Composition Data
(
ISO
,
Geneva
,
2003
).
30.
Calibration certificate DKD-08649-14-01_3458A_US28030999 and DKD_08643-14-01_3458A_US28031000 (Calibration Laboratory DKD-K-08649 for Pressure, Temperature, Humidity and Electrical Measurands, Siemens, Germany, January 28, 2014).
31.
S. M.
Sarge
, “
Calibration runs G486 and G539
” (personal communication,
PTB Braunschweig
,
Germany
,
2019
).
32.
K. F.
Schmid
, “
Untersuchungen an einem System aus Kammerofen und Gasbrenner mit integrierter Brennerkopfkühlung und Luftvorwärmung zur Heizgaserzeugung mit breiter Temperaturvarianz
,” Ph.D. thesis,
RWTH Aachen
,
Germany
,
1980
.
33.
M. E.
Wieser
and
M.
Berglund
,
Pure Appl. Chem.
81
,
2131
(
2009
).
34.
F. D.
Rossini
, “
Calibrations of calorimeters for reactions in a flame at constant pressure
,” in
Experimental Thermochemistry
(
Interscience Publishers
,
New York
,
1956
), Vol. 1, Chap. 4, pp.
59
74
.
35.
S. M.
Sarge
, Leaflet Absorptionsroehrchen – Auswertung Ergänzungen, 2010-09-20, with the attachments Absorptionsroehrchen - Praeparation und Waegung.pdf and Absorptionsroehrchen - Messprotokoll - 2008-01-11.pdf (personal communication,
PTB Braunschweig
,
Germany
,
2010
).
36.
Calibration certificate DKD-K-11801/14-05, G1–138 for No. K1419148, G1–137 for No. K1419149 and G1–216 for No. K1419540 (Calibration Laboratory DKD-K-11801 Kern & Sohn, Germany, May 12, 2014 and May 23, 2014).
37.
F. D.
Rossini
,
Bur. Stand. J. Res.
6
,
1
(
1930
).
38.
G.
Pilcher
,
H. A.
Skinner
,
A. S.
Pell
, and
A. E.
Pope
,
J. Chem. Soc. Faraday Trans. I
59
,
316
(
1963
).
39.
A.
Dale
,
C.
Lythall
,
J.
Aucott
, and
C.
Sayer
,
Thermochim. Acta
382
,
47
(
2002
).
40.
V.
Régnault
,
Mém. Cl. Sci. Acad. Sci. Inst. France
26
,
1
(
1862
).
41.
42.
E. D.
West
and
K. L.
Churney
,
J. Appl. Phys.
39
,
4206
(
1968
).
43.
S.
Sunner
, in
Combustion Calorimetry: Experimental Chemical Thermodynamics
, edited by
S.
Sunner
and
M.
Mansson
(
Pergamon Press
,
New York
,
1981
), Vol. 1.
44.
S. M.
Sarge
, Beschreibung Excel-Arbeitsmappe DeltaTad-18.xls (June 02, 2009) (personal communication,
PTB Braunschweig
,
Germany
,
2010
).
45.
F.
Haloua
,
B.
Hay
, and
E.
Foulon
,
J. Therm. Anal. Calorim.
111
,
985
(
2013
).
46.
W.
Wagner
,
N.
Kurzeja
, and
B.
Pieperbeck
,
Fluid Phase Equilib.
79
,
151
(
1992
).
47.
L.
Garcia
and
the Foxes Team
,
Software Per Calcolo Numerico
(
digilander-libero.it/foxes
,
2006
), found on the 2007 closed website http://digilander-libero.it/foxes/index.htm.
48.
W.
Hässelbarth
,
J.
Rauch
, and
S. M.
Sarge
,
J. Therm. Anal. Calorim.
109
,
1597
(
2012
).
49.
H. C.
Dickinson
,
Bull. Bur. Stand.
11
,
189
(
1915
).
50.
S. R.
Gunn
,
J. Chem. Thermodyn.
3
,
19
(
1971
).
51.
L.
Santos
,
M. T.
Silva
,
B.
Schröder
, and
L.
Gomes
,
J. Therm. Anal. Calorim.
89
,
175
(
2007
).
52.
International Association for the Properties of Water and Steam, IAPWS G5-01 (2016), Guideline on the Use of Fundamental Physical Constants and Basic Constants of Water (2016).
53.
ISO/TC 193 SC1
, “
Natural gas – Supporting information on the calculation of physical properties according to ISO 6976
,” Technical Report No. ISO/TR 29922:2017,
ISO
,
Geneva
,
2017
.
54.
Certificate of Analysis, Project No. 20-54983-004 (Cylinder No. 8431435) May 12, 2005 (Scott Speciality Gases, The Netherlands, 2005).
55.
Certificate BAM-G701/233 (Cylinder No. 8431435) February 21, 2006 (Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany, 2006).
56.
Product data sheet Methan N55, Air Liquide, Germany, 2019.
57.
N.
Kurzeja
and
S. M.
Sarge
, “
Reevaluation of the PTB GCV data of CH4
” (to be published).
58.
Certificate BAM-ZRM C723, sample W17248 of Cylinder No. 8431435, October 11, 2019 (Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany, 2019).
59.
G. T.
Armstrong
and
Th.
Jobe
, Jr.
,
Heating Values of Natural Gas and its Components
, NBSIR 82-2401 (
National Bureau of Standards
,
Washington, DC
,
1982
).
60.
F. D.
Rossini
,
Bur. Stand. J. Res.
7
,
329
(
1931
).
61.
F. D.
Rossini
,
Fundamental Measures and Constants for Science and Technology
(
CRC Press
,
Cleveland, Ohio
,
1974
).
62.
J. R.
Eckman
and
F. D.
Rossini
,
Bur. Stand. J. Res.
3
,
597
(
1929
).
63.
G. K.
Burgess
,
Bur. Stand. J. Res.
1
,
635
(
1928
).
64.
J.
Lee
,
S.
Kwon
,
W.
Joung
, and
D.
Kim
,
Int. J. Thermophys.
38
,
171
(
2017
).
65.
Y.
Alexandrov
,
Thermochim. Acta
382
,
55
(
2002
).
66.
F.
Haloua
,
J. N.
Ponsard
,
G.
Lartigue
,
B.
Hay
,
C.
Villermaux
,
E.
Foulon
, and
M.
Zaréa
,
Int. J. Therm. Sci.
55
,
40
(
2012
).
67.
J.
Rauch
(personal communication,
PTB Braunschweig
,
Germany
,
2010
).
68.
S. M.
Sarge
(personal communication,
PTB Braunschweig
,
Germany
,
2019
).
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