International comparison Refinery gas (CCQM-K77) Final Report

Transcription

1 Blad 1 van 71 International comparison Refinery gas (CCQM-K77) Final Report

2 Page 2 of 71 VSL Thijsseweg JA Delft Postbus AR Delft Nederland T F E info@vsl.nl I This work has been carried out by: On request of: Project number: G. Nieuwenkamp R.M. Wessel A.M.H. van der Veen P.R. Ziel CCQM Gas Analysis Working Group CCQM-K77

3 Page 3 of 71 To this report contributed: Qiao HAN National Institute of Metrology (NIM), No.18, Bei-San-Huan Dong Str., Beijing , China Dirk Tuma BAM Federal Institute for Materials Research and Testing, Unter den Eichen Berlin, Germany Jin-Chun Woo Korea Research Institute of Standards and Science (KRISS), Division of Quality of Life, P.O. Box 102, Yuseong, Taejeon, Republic of Korea Judit Tóthné Fűkő, Nagyné Szilágyi, Tamás Büki Magyar Kereskedelmi Engedélyezési Hivatal (Hungarian Trade Licensing Office) MKEH, Németvölgyi út 37-39, H-1124 Budapest, Hungary L. A. Konopelko, Y. A. Kustikov, T.A. Popova, V. V. Pankratov, M.N. Pir, E.V. Nazarov, L.V. Ehvalov, A.U. Timofeev, T.A. Kuzmina, A.V. Meshkov D.I. Mendeleyev Institute for Metrology (VNIIM), Department of Physical Chemical Measurements, 19, Moskovsky Prospekt, St-Petersburg, Russia Miroslava Valkova, Viliam Pätoprsty Slovak Institute of Metrology (SMU), Karloveská 63, Bratislava, Slovak Republic Michael Downey, Gergely Vargha, Andrew Brown, Martin Milton National Physical Laboratory (NPL), Teddington, Middlesex, TW11 0LW, UK

4 Page 4 of 71 Summary Refinery gas is a complex mixture of hydrocarbons and non-combustible gases (e.g., carbon monoxide, carbon dioxide, nitrogen, helium). It is obtained as part of the refining and conversion of crude oil. This key comparison aims to evaluate the measurement capabilities for these types of mixtures. The results of the key comparison indicate that the analysis of a refinery type gas mixture is for some laboratories a challenge. Overall, 4 laboratories (VSL, NIM, NPL and VNIIM) have satisfactory results. The results of some participants highlight some non-trivial issues, such as appropriate separation between saturated and unsaturated hydrocarbons, and issues with the measurement of nitrogen, hydrogen and helium.

5 Page 5 of 71 Table of contents Summary 4 Table of contents 5 List of figures 6 List of tables 7 1 Introduction 8 2 Design of the key comparison Field of measurement 2.2 Subject Participants Measurement standards Measurement protocol Schedule 2.7 Measurement equation Supported CMC-claims Degrees of equivalence 3 Results Measurement methods Data and evaluation 4 Discussion and conclusions References 26 Annex 1: purity tables of pure compounds and final mixture Measurement report of VSL Measurement report of BAM 33 Measurement report of MKEH Measurement report of KRISS Measurement report of NIM 44 Measurement report of NPL Measurement report of SMU Measurement report of VNIIM 64

6 Page 6 of 71 List of figures Figure 1: Degrees of equivalence for methane Figure 2: Degrees of equivalence for ethene Figure 3: Degrees of equivalence for ethane Figure 4: Degrees of equivalence for propene Figure 5: Degrees of equivalence for propane Figure 6: Degrees of equivalence for 1,3-butadiene Figure 7: Degrees of equivalence for 1-butene Figure 8: Degrees of equivalence for iso-butene Figure 9: Degrees of equivalence for hydrogen Figure 10: Degrees of equivalence for nitrogen Figure 11: Degrees of equivalence for helium... 24

7 Page 7 of 71 List of tables Table 1: List of participants... 9 Table 2: Nominal composition of the mixtures... 9 Table 3: Ranges supported by this key comparison Table 4: Summary of calibration methods and metrological traceability Table 5: Results and degrees of equivalence for methane (10-2 mol mol -1 ) Table 6: Results and degrees of equivalence for ethene (10-2 mol mol -1 ) Table 7: Results and degrees of equivalence for ethane (10-2 mol mol -1 ) Table 8: Results and degrees of equivalence for propene (10-2 mol mol -1 ) Table 9: Results and degrees of equivalence for propane (10-2 mol mol -1 ) Table 10: Results and degrees of equivalence for 1,3-butadiene (10-2 mol mol -1 ) Table 11: Results and degrees of equivalence for 1-butene (10-2 mol mol -1 ) Table 12: Results and degrees of equivalence for iso-butene (10-2 mol mol -1 ) Table 13: Results and degrees of equivalence for hydrogen (10-2 mol mol -1 ) Table 14: Results and degrees of equivalence for nitrogen (10-2 mol mol -1 ) Table 15: Results and degrees of equivalence for helium (10-2 mol mol -1 ) Table 16: Purity table of 1-Butene Table 17: Purity table of 1,3 - Butadiene Table 18: Purity table of Propene Table 19: Purity table of Ethene Table 20: Purity table of Helium Table 21: Purity table of iso-butene Table 22: Purity table of Propane Table 23: Purity table of Ethane Table 24: Purity table of Nitrogen Table 25: Purity table of Hydrogen Table 26: Purity table of Methane Table 27: Purity table of final mixture... 29

8 Page 8 of 71 1 Introduction Carbon trading schemes are driving a need for measurement of intermediate products in industry which are now used as energy sources in other processes. One example of these products is refinery gas, which is rich in hydrogen and unsaturated hydrocarbons. A key-comparison for a refinery gas type gas mixture was organised to underpin new, and already existing, CMC claims in the BIPM database. Just as in other key comparisons in gas analysis [1], the values as obtained from gravimetric preparation in accordance with ISO 6142 [2] are taken as the reference values.

9 Page 9 of 71 2 Design of the key comparison 2.1 Field of measurement Amount of substance 2.2 Subject Key comparison in the field of refinery gas type mixtures 2.3 Participants Table 1 lists the participants in this key comparison. Table 1: List of participants Acronym Country Institute NIM CN National Institute of Metrology, Beijing, PR China BAM DE Federal Institute for Materials Research and Testing, Berlin, Germany KRISS KR Korea Research Institute of Standards and Science, Daejon, South-Korea MKEH HU Hungarian Trade Licensing Office, Budapest, Hungary VSL NL Van Swinden Laboratorium, Delft, the Netherlands VNIIM RU D.I. Mendeleyev Institute for Metrology, St. Petersburg, Russia SMU SK Slovak Institute of Metrology, Bratislava, Slovak Republic NPL UK National Physical Laboratory, Teddington, Middlesex, United Kingdom 2.4 Measurement standards A suite of mixtures has been gravimetrically prepared for this comparison. Table 2 lists the nominal composition of the mixture used (expressed as amount of substance fractions). Table 2: Nominal composition of the mixtures Component x (10-2 mol mol -1 ) Methane Ethene Ethane 1 5 Propene 1 5 Propane ,3-Butadiene Butene Iso-butene Hydrogen 7 10 Nitrogen 3 5 Helium Balance

10 Page 10 of 71 The mixtures were prepared gravimetrically and subsequently verified. The preparation of the mixtures was carried out using the normal procedure for the preparation of gas mixtures [3]. After preparation, the mixtures were verified by comparing the key comparison mixtures with VSL s own PSMs. 2.5 Measurement protocol The laboratories were requested to use their normal procedure for the measurement of the gas mixture composition. For participation in this key comparison, it had been requested that participants determine all components in the mixture, and not just a subset. The participants were asked to perform at least three measurements, on different days with independent calibrations. Laboratories were allowed to use the same set of measurement standards for these calibrations. The participants were also requested to describe their methods of measurement, and the models used for evaluating the measurement uncertainty. A typical numerical example of the evaluation of measurement uncertainty had to be included for each component. 2.6 Schedule The schedule for this key comparison was as follows November 2009 Agreement of protocol and participants list February-May 2010 Preparation of mixtures May 2010 Distribution of mixtures December 2010 Reports and cylinders back at VSL April 2011 Draft A report November 2011 Draft B report 2.7 Measurement equation The reference values used in this key comparison are based on gravimetry, and the purity verification of the parent gases/liquids. All mixtures underwent verification prior to shipping to the participants. After return of the cylinders, they were verified once more to reconfirm the stability of the mixtures. The measurement equation reads as [4] x i, prep xi, grav + xi, purity = (1) and for the associated standard uncertainty, the following expression is used u i, prep = ui, grav ui, purity (2) The amount of substance fraction of mixture i from preparation is denoted by x i,prep, that from weighing by x i,grav and the correction due to purity analysis by x i,purity. The KCRV (x i,ref) is set equal to x i,prep. The expression for the standard uncertainty of the KCRV reads as u i, ref = ui, prep ui, ver (3) The values for u i,ver are given in the tables containing the results of this key comparison. The purity tables for all pure compounds used in the preparation of the mixtures and the final purity table of one of the comparison mixtures are given in Annex 1.

11 Page 11 of Supported CMC-claims During its twenty sixth meeting, the CCQM-GAWG decided that this key comparison can be used to support CMC claims for typical refinery gas and coke oven type gas mixtures containing the following components over the amount of substance fraction ranges listed. Table 3: Ranges supported by this key comparison Component Range (10-2 mol mol -1 ) methane 5 to 70 ethene 5 to 20 ethane 1 to 10 propene 0.5 to 10 propane 0.1 to 5 1,3-butadiene 0.5 to 3 1-butene 0.1 to 1 iso-butene 0.1 to 1 n-butane 0.1 to 2 n-pentane 0.1 to 1 hydrogen 5 to 70 nitrogen 1 to 70 helium 1 to Degrees of equivalence A unilateral degree of equivalence in key comparisons is defined as [6] x = D = x x KCRV, (4) i i i and the uncertainty of the difference D i at 95% level of confidence. Here x KCRV denotes the key comparison reference value, and x i the result of laboratory i. 1 Appreciating the special conditions in gas analysis, it can be expressed as x = D = x x (5) i i i i,ref Assuming that the aggregated error terms are uncorrelated, the standard uncertainty of D i can be expressed as ( x ) = + u + u u 2 u i i, lab i, prep + (6) i, ver As discussed, the combined standard uncertainty of the reference value comprises that from preparation and that from verification for the mixture involved. 1 Each laboratory receives one cylinder, so that the same index can be used for both a laboratory and a cylinder.

12 Page 12 of 71 3 Results 3.1 Measurement methods The measurement methods used by the participants are described in annex A of this report. A summary of the calibration methods, the dates of measurement and reporting, and the way in which metrological traceability is established is given in table 4. Table 4: Summary of calibration methods and metrological traceability Laboratory Measurement dates Calibration Traceability Number of measurements Measurement technique NIM Single point Own standards 55 GC-FID-TCD (2) BAM Bracketing Own standards 2 GC-TCD KRISS Bracketing Own standards 3 GC-TCD + GC-FID MKEH Single point Own standards 3 GC-FID-TCD VSL ISO 6143 [5] Own standards 3 GC-TCD + GC-FID VNIIM Single point Own standards 4 GC-FID-TCD SMU ISO 6143 [5] Own standards 3 GC- FID + GC-TCD-FID NPL Nov Dec 2010 ISO 6143 [5] Own standards GC-TCD-FID + µgc-tcd NPL data were normalised to 99.99% to allow for a total of 100 µmol/mol of impurities of which 50 µmol/mol was identified as cis-2-butene and 50 µmol/mol as unknown. 3.2 Data and evaluation In this section, the results of the key comparison are summarised. In the tables, the following data are presented x prep u prep u ver u ref x lab U lab k lab amount of substance fraction, from preparation standard uncertainty of x prep standard uncertainty from verification combined standard uncertainty of reference value result of laboratory stated expanded uncertainty of laboratory, at 95% level of confidence stated coverage factor x difference between laboratory result and reference value k assigned coverage factor for degree of equivalence U( x) Expanded uncertainty of difference x, at 95% level of confidence 2 The relative differences are given with respect to the key comparison reference value (KCRV). 2 As defined in the MRA [6], a degree of equivalence is given by x and U( x).

13 Page 13 of 71 Table 5: Results and degrees of equivalence for methane (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % % Table 6: Results and degrees of equivalence for ethene (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % %

14 Page 14 of 71 Table 7: Results and degrees of equivalence for ethane (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % % Table 8: Results and degrees of equivalence for propene (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % %

15 Page 15 of 71 Table 9: Results and degrees of equivalence for propane (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % % Table 10: Results and degrees of equivalence for 1,3-butadiene (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % %

16 Page 16 of 71 Table 11: Results and degrees of equivalence for 1-butene (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % % Table 12: Results and degrees of equivalence for iso-butene (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % %

17 Page 17 of 71 Table 13: Results and degrees of equivalence for hydrogen (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % % Table 14: Results and degrees of equivalence for nitrogen (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % %

18 Page 18 of 71 Table 15: Results and degrees of equivalence for helium (10-2 mol mol -1 ) Lab Cylinder x prep u prep u ver u ref x lab U lab k lab D i D i/x k U(D i) U(D i)/x VSL D % % BAM D % % MKEH D % % KRISS D % % NIM D % % NPL D % % SMU D % % VNIIM D % % Four laboratories (VNIIM, SMU, KRISS and NIM), have calculated the helium content by difference, i.e., using the formula ( He) = x 1 i x i were x i = amount fraction of the analysed components The associated standard uncertainty of helium amount fraction follows from propagating the uncertainties of the analysed fractions accordingly, viz. u 2 ( x( He) ) = u ( ) i x i

19 Page 19 of Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 1: Degrees of equivalence for methane 0.6 Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 2: Degrees of equivalence for ethene

20 Page 20 of Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 3: Degrees of equivalence for ethane 0.2 Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 4: Degrees of equivalence for propene

21 Page 21 of Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 5: Degrees of equivalence for propane Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 6: Degrees of equivalence for 1,3-butadiene

22 Page 22 of Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 7: Degrees of equivalence for 1-butene 0.54 Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 8: Degrees of equivalence for iso-butene

23 Page 23 of 71 Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 9: Degrees of equivalence for hydrogen Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 10: Degrees of equivalence for nitrogen

24 Page 24 of Degree of equivalence (cmol mol -1 ) VSL BAM MKEH KRISS NIM Laboratory NPL SMU VNIIM Figure 11: Degrees of equivalence for helium

25 Page 25 of 71 4 Discussion and conclusions The results of the key comparison indicate that the analysis of a refinery type gas mixture is for some laboratories a challenge. Overall, 4 laboratories (VSL, NIM, NPL and VNIIM) have satisfactory results. SMU has satisfying results for all components except propane. BAM has in principle satisfying results for all components but the applied method failed to separate 1-butene from iso-butene. Therefore no result was reported for 1-butene and the result for isobutene was too high by the amount of 1-butene. The results for the hydrocarbon components from MKEH are most likely negatively influenced by the applied normalisation of the total sum. The values for the non hydrocarbon compounds (nitrogen, hydrogen and helium) were all (very) far from the reference values. The results for KRISS, with the exception of 3 components, are not in consensus with the reference values. KRISS has used two freshly prepared calibration gas mixtures but a root cause analysis revealed mistakes in the calculation of the gas composition from preparation.

26 Page 26 of 71 References [1] Alink A., The first key comparison on Primary Standard gas Mixtures, Metrologia 37 (2000), pp [2] International Organization for Standardization, ISO 6142 Gas analysis -- Preparation of calibration gas mixtures -- Gravimetric method, ISO Geneva, 2001 [3] Alink A., Van der Veen A.M.H., Uncertainty calculations and the preparation of primary gas mixtures. 1. Gravimetry, Metrologia 37 (2000), pp [4] van der Veen A.M.H, Chander H., Ziel P.R., de Leer E.W.B., Smeulders D., Besley L., Smarçao da Cunha V., Zhou Z., Qiao H., Heine H-J., Tichy J., Lopez Esteban T., Kato K., Nagyné Szilágyi Z., Seog Kim J., Woo J-C., Bae H-G., Pérez Castorena A., Rangel Murillo F., Serrano Caballero V.M., Ramírez Nambo C., Avila Salas M.J., Rakowska A., Dias F., Konopelko L.A., Popova T.A., Pankratov V.V., Kovrizhnih M.A., Kuzmina T.A., Efremova O.V., Kustikov Y.A., Musil S., Milton M.J.T. International comparison: Natural gas type II, Metrologia 47 (2010), Tech. Suppl., [5] International Organization for Standardization, ISO 6143:2001 Gas analysis - Determination of composition of calibration gas mixtures - Comparison methods, 2 nd edition [6] CIPM, Mutual recognition of national measurement standards and of calibration and measurement certificates issued by national metrology institutes, Sèvres (F), October 1999

27 Page 27 of 71 Annex 1: purity tables of pure compounds and final mixture Purity tables of pure gases Table 16: Purity table of 1-Butene Component mass fraction amount fraction uncertainty Carbon dioxide CO Butene C 4H n-butane C 4H Nitrogen N Oxygen O cis-2-butene C 4H trans-2-butene C 4H Table 17: Purity table of 1,3 - Butadiene Component mass fraction amount fraction uncertainty 1,3-butadiene C 4H nitrogen N oxygen O cis-2-butene C 4H trans-2-butene C 4H ,5-cyclooctadieën C 8H Table 18: Purity table of Propene Component mass fraction amount fraction uncertainty Ethane C 2H Propene C 3H Propane C 3H Nitrogen N Oxygen O Table 19: Purity table of Ethene Component mass fraction amount fraction uncertainty Ethene C 2H Ethane C 2H Nitrogen N Oxygen O Table 20: Purity table of Helium Component mass fraction amount fraction uncertainty Methane CH Carbon monoxide CO Carbon dioxide CO Helium He Hydrogen H Water H 2O Nitrogen N

28 Page 28 of 71 Oxygen O Table 21: Purity table of iso-butene Component mass fraction amount fraction uncertainty Carbon dioxide CO ,3-Butadiene C 4H Butene C 4H iso-butene C 4H Nitrogen N Oxygen O cis-2-butene C 4H trans-2-butene C 4H Table 22: Purity table of Propane Component mass fraction amount fraction uncertainty Methane CH Ethane C 2H Propene C 3H Propane C 3H Nitrogen N Table 23: Purity table of Ethane Component mass fraction amount fraction uncertainty Ethane C 2H Nitrogen N Oxygen O Table 24: Purity table of Nitrogen Component mass fraction amount fraction uncertainty Argon Ar Methane CH Carbon monoxide CO Carbon dioxide CO Hydrogen H Water H 2O Nitrogen N Oxygen O Table 25: Purity table of Hydrogen Component mass fraction amount fraction uncertainty Methane CH Carbon monoxide CO Carbon dioxide CO Hydrogen H Water H 2O Nitrogen N Oxygen O

29 Page 29 of 71 Table 26: Purity table of Methane Component mass fraction amount fraction uncertainty Methane CH Carbon dioxide CO Ethene C 2H Ethane C 2H Propane C 3H Hydrogen H Water H 2O Nitrogen N Oxygen O Table 27: Purity table of final mixture Component mass fraction amount fraction uncertainty Argon Ar Methane CH Carbon monoxide CO Carbon dioxide CO Ethane C 2H Ethane C 2H Propene C 3H Propane C 3H ,3-Butadiene C 4H Butene C 4H iso-butene C 4H n-butane C 4H Helium He Hydrogen H Water H 2O Nitrogen N Oxygen O cis-2-butene C 4H trans-2-butene C 4H ,5-cyclooctadieën C 8H

30 Page 30 of 71 Measurement report of VSL Cylinder number: D Measurement #1 Component Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H H N He number of replicates Measurement #2 Component Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H H N He Measurement #3 Component Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H H N He number of replicates number of replicates

31 Page 31 of 71 Results Component Result (mol/mol) Assigned Expanded uncertainty (% relative) CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H H N He Coverage factor Analytical conditions Helium and Hydrogen were analysed on an Agilent GC-TCD with a 3 m 1/8 Molsieve 13X column using Argon carrier. Nitrogen and Methane were analysed on an Agilent GC-TCD with a 2 m 1/16 Molsieve 13X column using Helium carrier. Ethene and the higher hydrocarbons were analysed on an Agilent GC-FID with a 25 m 0.32mm 8 µm Al 2O 3 PLOT column using Helium carrier. The analytical systems where calibrated each day using four gravimetrical prepared multicomponent refinery gas mixtures covering the range of our CMC claim. A linear calibration function was used to determine the concentrations of the components in the K-77 mixture. The regression software follows the methods described in ISO The gravimetric mole fraction and the gravimetric uncertainty as well as the peak area and the standard deviation in analyses were used to calculate the calibration function. The peak area and standard deviation for the K77 mixture were used to predict the amount of substance fraction of each component. For each measurement the reported standard uncertainties were calculated. The final value as reported is the mean of the three measurements and the reported expanded uncertainty is the combination of the reported standard uncertainties multiplied by the coverage factor. Calibration standards Four existing Primary Standard Mixtures were used for the analysis of the K77 mixture. Their compositions are listed below (the uncertainties are given as standard uncertainties): VSL Component amount fraction uncertainty CH C 2H C 2H C 3H C 3H ,3 -C 4H C 4H iso-c 4H He

32 Page 32 of 71 H N VSL Component amount fraction uncertainty CH C 2H C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H He H N VSL Component amount fraction uncertainty CH C 2H C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H He H N VSL Component amount fraction uncertainty CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H He H N All mixtures were prepared from pure gases of which the impurities were analysed by typical GC methods.

33 Page 33 of 71 Measurement report of BAM Cylinder number: D Reference method: The analysis was carried out using gas chromatography. GC: Siemens Maxum edition II, multichannel process GC; column: packed columns; oven temperature: 60 C, isothermal; detector: TCD; carrier gas: nitrogen / helium This equipment was employed for the analysis of all compounds. Calibration standards: The standards which were employed in this study were prepared according to ISO 6142: 2001 Gas analysis Preparation of calibration gas mixtures Gravimetric method. Depending on the concentrations of the targeted compounds, standards were prepared individually from pure gases or from pre-mixtures. The standards were analyzed and verified according to ISO 6143: 2001 Gas analysis Comparison methods for determining and checking the composition of calibration gas mixtures. All pure gases were tested for impurities before use by gas chromatography. The analysis of methane, helium, and nitrogen employed a PDID, the analysis of the other compounds employed FID. The calibration standards did not contain 1-butene, since only one butene peak was recorded during a test run of the sample (Perkin Elmer AutoSystem XL; carrier gas: helium; oven temperature: 0 C to 30 C, liquid nitrogen administration; column: capillary column, 50 m * 0.32 µm LP-SIL-8-CB; detector: FID; data processing: TotalChrom Workstation) even at the lowest possible temperature. As 1-butene was not specified on the cylinder label, we assumed that our sample did not contain it. Therefore, the calibration standard did only contain iso-butene. BAM Component Assigned value x (mol/mol) Expanded uncertainty % relative k = 2 Nitrogen Hydrogen Helium Propane Ethane Methane Iso-butene Propene Ethene ,3-Butadiene

34 Page 34 of 71 BAM C Component Assigned value x (mol/mol) Expanded uncertainty % relative k = 2 Nitrogen Hydrogen Oxygen Helium Neopentane n-hexane Propane Isobutane n-butane Ethane Carbon dioxide n-pentane Isopentane Methane Propene Carbon monoxide Ethene Instrument calibration: The bracketing technique was applied for the analysis of nitrogen, ethane, propene, and propane. The sequence to be executed was: 3 times standard low 3 time standard high 3 times sample 3 times standard low 3 times sample 3 times standard high 3 times sample 3 times standard low 3 times standard high. The other compounds were analyzed by one-point calibration. The number of runs during the analysis was the same as for the bracketing technique. Neither a pressure nor a temperature correction was applied. Sample handling: Prior to analysis, the cylinders were heated (60 ) for 8 hours and subsequently rolled for about 12 hours. This procedure was executed three times. Each cylinder was equipped with a pressure regulator that was purged three times by sequential evacuation and pressurization with the respective mixture. There was a continuous flow (about 4 ml/min) through the sample loop.

35 Page 35 of 71 Evaluation of measurement uncertainty: The uncertainty is the combined uncertainty resulting from the following sources A and B: A: gravimetrically prepared standards. Uncertainty of the balances, uncertainty from the impurities of the pure gases, uncertainty from the matrix compound of the pure gases, residual uncertainty of non-recovered errors related to the gas cylinder and to the gaseous compounds, uncertainty related to the stability of the calibration mixture B: analysis. Uncertainty of the (gravimetrically prepared) standards, standard deviation from the measurements, standard deviation from the calibration, standard deviation from the calibration, residual uncertainty of non-recovered errors Measurement #1 Component Date (dd/mm/yy) Result (mol/mol) CH 4 21/11/ C 2 H 4 21/11/ C 2 H 6 21/11/ C 3 H 6 21/11/ C 3 H 8 21/11/ ,3-C 4 H 6 21/11/ C 4 H 8 21/11/10 Not detected iso-c 4 H 8 21/11/ H 2 21/11/ N 2 21/11/ He 21/11/ Standard deviation (% relative) 2.32 number of replicates 5 * * * * * * 3 5 * * * * * 3 Measurement #2 Component Date (dd/mm/yy) Result (mol/mol) CH 4 26/11/ C 2 H 4 C 2 H 6 C 3 H 6 C 3 H 8 1,3-C 4 H 6 1-C 4 H 8 26/11/10 26/11/10 26/11/10 26/11/10 26/11/10 26/11/ Standard deviation (% relative) number of replicates 5 * 3 5 * 3 5 * 3 5 * 3 5 * 3 5 * 3 Not detected 5 * 3

36 Page 36 of 71 iso-c 4 H 8 26/11/ * 3 H 2 26/11/ * 3 N 2 26/11/ * 3 He 26/11/ * 3 Results Component Date (dd/mm/yy) Result (mol/mol) mean average value Expanded uncertainty (mol/mol) k = 2 number of replicates CH C 2 H C 2 H C 3 H C 3 H ,3-C 4 H C 4 H 8 Not detected iso-c 4 H H 2 N 2 He

37 Page 37 of 71 Measurement report of MKEH Cylinder number: D Measurement #1 Component Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H H N He number of replicates Measurement #2 Component Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H H N He number of replicates Measurement #3 Component Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H H N He number of replicates

38 Page 38 of 71 Results Component Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H iso-c 4H H N He number of replicates Reference Method The measurements were carried out by HP 6890 GC-TCD/FID fitted with a 10-port gas sampling valve. Details of the columns and method parameters are given in the table below: Components Hydrocarbons N 2, H 2 Detector FID TCD Column Agilent J&W Coloumn HP-AL/S 50m, 0.530mm, 15.0 um film RESTEK packed Coloumn HS-A 120/ m, 0.75 mmid, 1/16 inod Sulfinert NOC Oven temperature 120 o C 40» 190 o C, 4 o C/min Carrier Gas He Ar Result of Helium was calculated as remained value from 100 % after the summa the other components. The uncertainty of this He value comes from the all components uncertainties. Calibration standards The Calibration Standard was prepared gravimetrically according to ISO Uncertainties of the components came from the gravimetric method and the purity declaration of the gases. Composition of calibration standard N o OMH205 Components Gravimetric value, x ppm (mol/mol) Expanded uncertainty, U (k=2) N CH C 2H C 2H C 3H C 3H ,3-C 4H C 4H i-c 4H H He

39 Page 39 of 71 Instrument Calibration: Direct comparison with the Standard No OMH205. Sample handling Sample was transferred continually to the instrument on low pressure checked by differential pressure controller (10 mbar). Evaluation of measurement uncertainty We took to account 3 main sources of the uncertainties of each component: 1. u1: experimental standard deviation of the mean of sample measurements, 2. u2: uncertainty of the calibration standard. It contains the uncertainty of the purity of the parent gases and uncertainty of the weighing. See the table of the calibration standard. 3. u3: experimental standard deviation of the mean of standard measurements - was calculated in this revised report. The combined uncertainty: u = u u2 u3 It was calculated the effective degree of freedom for each component. We used coverage factor k, which for a t-distribution with degree of freedom corresponds to a coverage probability of approximately 95%. The expanded uncertainty: U=k*u

40 Page 40 of 71 Measurement report of KRISS Cylinder number: D (residual pressure, 1.5 MPa) Measurement #1 Component Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH 4 Dec C 2H 4 Dec C 2H 6 Dec C 3H 6 Dec C 3H 8 Dec ,3-C 4H 6 Dec C 4H 8 Dec iso-c 4H 8 Dec H 2 Dec N 2 Dec He Balance number of replicates Measurement #2 Component Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH 4 Dec C 2H 4 Dec C 2H 6 Dec C 3H 6 Dec C 3H 8 Dec ,3-C 4H 6 Dec C 4H 8 Dec iso-c 4H 8 Dec H 2 Dec N 2 Dec He Balance number of replicates Measurement #3 Date (dd/mm/yy) Result (mol/mol) Standard deviation (% relative) CH 4 Dec C 2H 4 Dec C 2H 6 Dec C 3H 6 Dec C 3H 8 Dec ,3-C 4H 6 Dec C 4H 8 Dec iso-c 4H 8 Dec H 2 Dec N 2 Dec He Balance number of replicates