Interlaboratory Proficiency Test 07/2017

Transkriptio

1 REPORTS OF THE FINNISH ENVIRONMENT INSTITUTE Interlaboratory Proficiency Test 07/2017 Gross an net calorific values in fuels Mirja Leivuori, Minna Rantanen, Riitta Koivikko, Keijo Tervonen, Sari Lanteri an Markku Ilmakunnas Finnish Environment Institute

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3 REPORTS OF THE FINNISH ENVIRONMENT INSTITUTE Interlaboratory Proficiency Test 07/2017 Gross an net calorific values in fuels Mirja Leivuori 1, Minna Rantanen 2, Riitta Koivikko 1, Keijo Tervonen 1, Sari Lanteri 1 an Markku Ilmakunnas 1 1) Finnish Environment Institute, Laboratory centre, Helsinki, Finlan 2) Eurofins Environment Testing Finlan Oy, Lahti, Finlan SYKE Helsinki 2017 Finnish Environment Institute

4 REPORTS OF THE FINNISH ENVIRONMENT INSTITUTE Finnish Environment Institute SYKE Proftest SYKE Layout: Markku Ilmakunnas The publication is also available in the Internet: hela.helsinki.fi/syke ISBN (pbk.) ISBN (PDF) ISSN (print) ISSN (Online) Author(s): Mirja Leivuori, Minna Rantanen, Riitta Koivikko, Keijo Tervonen, Sari Lanteri an Markku Ilmakunnas Publisher an financier of publication: Finnish Environment Institute (SYKE) P.O. Box 140, FI Helsinki, Finlan, Phone , syke.fi. Year of issue: 2017

5 ABSTRACT Interlaboratory Proficiency Test 07/2017 Proftest SYKE arrange the proficiency test (PT) for measurement the gross an the net calorific value, the content of ash, carbon, nitrogen, hyrogen, moisture, sulphur an volatile matter in peat, woo pellet (not sulphur) an coal samples in September In total, there were 26 participants in the PT. Also, the participants ha the possibility to calculate the emission factor for the peat an coal samples. In total, 89 % of the participants reporte satisfactory results when the eviations of 1 30 % from the assigne values were accepte. In measurement of the gross calorific value from the peat sample 100 %, from the woo pellet sample 83 % an from the coal sample 94 % of the results were satisfactory. In measurement of the net calorific value from the peat sample 100 %, from the woo pellet 83 % an from the coal sample 92 % of the results were satisfactory. The robust mean or mean of the reporte results by the participants were use as the assigne values for measurements. The evaluation of performance was base on the z an E n scores. The evaluation of performance was not one for the measurement of M a in all samples, H in the peat sample an N in the woo pellet sample. Warm thanks to all the participants of this proficiency test! Keywors: Proficiency test, interlaboratory comparison, coal, peat, woo pellet, calorific value, emission factor, ash, moisture, carbon, sulphur, nitrogen, hyrogen, volatile matter, environmental laboratories TIIVISTELMÄ Laboratorioien välinen pätevyyskoe 07/2017 Proftest SYKE järjesti syyskuussa 2017 pätevyyskokeen kalorimetrisen ja tehollisen lämpöarvon sekä tuhkan, veyn, typen, rikin, haihtuvien yhisteien ja kosteuen määrittämiseksi turpeesta, puupelletistä (ei rikkiä) ja kivihiilestä. Lisäksi osallistujilla oli mahollisuus arvioia/laskea turve- ja kivihiilinäytteien päästökerroin. Pätevyyskokeessa oli yhteensä 26 osallistujaa. Koko tulosaineistossa hyväksyttäviä tuloksia oli 89 %, kun vertailuarvosta sallittiin 1 30 % poikkeama. Kalorimetrisen lämpöarvon tuloksista oli hyväksyttäviä 100 % (turve), 83 % (puupelletti) ja 94 % (kivihiili). Tehollisen lämpöarvon tuloksille vastaavat hyväksyttävien tulosten osuuet olivat 100 % (turve), 83 % (puupelletti) ja 92 % (kivihiili). Vertailuarvona käytettiin osallistujatulosten robustia keskiarvoa tai keskiarvoa. Pätevyyen arviointi tehtiin z- ja E n -arvojen avulla. Tulosten arviointia ei tehty testinäytteien kosteuspitoisuuen määritykselle, turpeen veyn ja puupelletin typen määrityksille. Kiitos pätevyyskokeen osallistujille! Avainsanat: pätevyyskoe, vertailumittaus, kalorimetrinen lämpöarvo, tehollinen lämpöarvo, päästökerroin, tuhka, kosteus, hiili, rikki, typpi, haihtuvat yhisteet ja vety, turve, puupelletti, hiili, ympäristölaboratoriot SAMMANDRAG Provningsjämförelse 07/2017 Proftest SYKE genomföre i september 2017 en provningsjämförelse som omfattae bestämningen av kalorimetriskt och effektivt värmeväre, svavel, väte, kol, kväve, askhalt, flykthalt och fukthalt i torv, trä pellet (inte svavel) och stenkol. Det var en möjlighet att beräkna emissionfaktor i torv och stenkol prover. Totalt 26 eltagarna eltog i jämförelsen. Som referensväre för analyternas koncentration använes mest et robusta meelväret av eltagarnas resultat. Resultaten väreraes me hjälp av z och E n vären. I jämförelsen var 89 % av alla resultaten acceptabel, när en total eviation på 1 30 % från referensväret tilläts. Av et kalorimetriska värmeväret var 100 % acceptabla (torv), 83 % (trä pellet) och 94 % (stenkol). För resultaten av et effektiva värmeväret var 100 % (torv), 83 % (trä pellet) och 92 % (stenkol) acceptabla. Det var inte gjorts värering till fuktighalt i alla prover, beräkning av väte i torv provet och nitrogen i trä pellet. Ett varmt tack till alla eltagarna i testet! Nyckelor: provningsjämförelse, kalorimetriskt och effektivt värmeväre, emissionfaktor, svavel, väte, kol, nitrogen, askhalt, flykthalt fukthalt stenkol, torv, trä pellet, miljölaboratorier

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7 CONTENTS Abstract Tiivistelmä Sammanrag Introuction Organizing the proficiency test Responsibilities s Samples an elivery Homogeneity Feeback from the proficiency test Processing the ata Pretesting the ata Assigne values Stanar eviation for proficiency assessment an results evaluation Results an conclusions Results Analytical methos Gross an net calorific value Measurement of carbon, hyrogen, nitrogen, sulphur, moisture, ash an volatile matter Uncertainties of the results Estimation of emission factor Evaluation of the results Summary Summary in Finnish References APPENDIX 1 : s in the proficiency test APPENDIX 2 : Preparation of the samples APPENDIX 3 : Homogeneity of the samples APPENDIX 4 : Feeback from the proficiency test APPENDIX 5 : Evaluation of the assigne values an their uncertainties APPENDIX 6 : Terms in the results tables APPENDIX 7 : Results of each participant APPENDIX 8 : Results of participants an their uncertainties APPENDIX 9 : Summary of the z an E n scores APPENDIX 10 : s in ascening orer APPENDIX 11 : Analytical measurements an backgroun information for calculations APPENDIX 12 : Results groupe accoring to the methos APPENDIX 13 : Examples of measurement uncertainties reporte by the participants Proftest SYKE CAL 07/17 5

8 6 Proftest SYKE CAL 07/17

9 1 Introuction Proftest SYKE carrie out the proficiency test (PT) for analysis of gross an net calorific value in fuels in September 2017 (CAL 07/2017). In total there were 26 participants in the PT. In the PT, gross an net calorific value, C, S, H, N, moisture content of the analysis sample (M a, ), ash content as well as volatile matter (V b ) were teste in peat, woo pellet (not S) an coal samples. Finnish Environment Institute (SYKE) is appointe National Reference Laboratory in the environmental sector in Finlan. The uties of the reference laboratory inclue proviing interlaboratory proficiency tests an other comparisons for analytical laboratories an other proucers of environmental information. This proficiency test has been carrie out uner the scope of the SYKE reference laboratory an it provies an external quality evaluation between laboratory results, an mutual comparability of analytical reliability. The proficiency test was carrie out in accorance with the international guielines ISO/IEC17043 [1], ISO [2] an IUPAC Technical report [3]. The Proftest SYKE has been accreite by the Finnish Accreitation Service (FINAS) as a proficiency testing provier (PT01, ISO/IEC 17043, This proficiency test has been carrie out uner the accreitation scope of the Proftest SYKE. 2 Organizing the proficiency test 2.1 Responsibilities Organizer: Proftest SYKE, Finnish Environment Institute (SYKE), Laboratory Centre Ultramariinikuja 4 (formerly Hakuninmaantie 6), FI Helsinki, Finlan Phone: proftest@environment.fi The responsibilities in organizing the proficiency test were as follows: Mirja Leivuori coorinator Riitta Koivikko substitute of coorinator Keijo Tervonen technical assistance Markku Ilmakunnas technical assistance Sari Lanteri technical assistance Co-operation: Minna Rantanen from Eurofins Environment Testing Finlan Oy (formerly Ramboll Finlan Oy) was participating in organizing the proficiency test as well as acting analytical expert. Proftest SYKE CAL 07/17 7

10 Subcontracting: The peat, woo pellet an coal samples were homogenate an ivie into sub-samples at the laboratory of Water Protection Association of the Kokemäenjoki River in Tampere (Finlan, testing laboratory T064 accreite by FINAS, Samples were teste by Eurofins Environment Testing Finlan Oy (T039 accreite by FINAS, s In total 26 participants took part in this proficiency test, of which 8 were from Finlan an 18 from other countries (Appenix 1). Altogether 77 % of the participants use accreite analytical methos at least for a part of the measurements. The samples were teste at the laboratory of Eurofins Environment Testing Finlan Oy, Vantaa an their participant coe is 18 in the result tables. 2.3 Samples an elivery Three ifferent fuel samples were elivere to the participants: peat (B1), woo pellet (B2) an coal (K1) samples. Gross (q V,gr, ) an net (q p,net, ) calorific value, C, S, H, N, moisture content of the analysis sample (M a, ), ash content as well as volatile matter (V b ) were teste in peat, woo pellet (not S) an coal samples. The material for the peat sample (B1) was collecte from the Finnish marshlan. The material was air rie an groune by the mill with 500 µm sieve before homogenization an sample iviing. The peat sample was prepare by Labtium in Jyväskylä (Finlan). The woo pellet sample (B2) was provie by Vapo an it was pre-treate (grining) by Labtium. The raw material for woo pellets was spruce sawust. The material was first crushe with a cutting mill an then groune by the mill with 1000 µm sieve before homogenization an sample iviing. The coal sample (K1) was prepare from har coal by the Helen Lt (Finlan). All samples were homogenize an ivie into sub-samples at the laboratory of Water Protection Association of the Kokemäenjoki River in Tampere. The sample preparation is escribe in etails in the Appenix 2. In the cover letter elivere with the samples, the participants were instructe first to store the samples close for one ay after their arrival an then to measure the moisture content of the analysis sample (M a ) as the first measurement. The samples were instructe to be homogenize before measurements an to be store in a ry place at room temperature. Further, the moisture content of the analysis sample was instructe to be measure on every ay of measurements. This was important as it eliminates the influence of humiity on the measurements. The participants were also aske to report the relative humiity (%) of the measuring room as an average of the measuring ates. 8 Proftest SYKE CAL 07/17

11 s ha the possibility to estimate/calculate the emission factor (as receive), EF, for peat an coal samples. For this estimation/calculation the total moisture contents of the samples as receive (M ar ) were given: peat B %, coal K1 9.6 % The samples were elivere on 1 September 2017 to the participants. The samples arrive to the participants mainly latest on 8 September The samples were requeste to be measure an the results to be reporte latest on 25 September Two participants elivere the results one ay later. The preliminary results were elivere to the participants via ProftestWEB an on 2 October Homogeneity Homogeneity of the samples B1, B2 an K1 was teste by measuring the gross calorific value an ash content as uplicate eterminations from five subsamples (Appenix 3). Moreover, the other measurans were teste from two subsamples as uplicate measurements. Accoring to the homogeneity test results, all samples were consiere homogenous. Particle size istribution was also teste from one sub sample of peat (B1) an coal (K1). The requirement of particle sizes given in the international stanars was not totally fulfille (Appenix 2). However, base on the results of this PT this seems not to have influence the performance of the participants measuring the coal sample. 2.5 Feeback from the proficiency test The feeback from the proficiency test is shown in Appenix 4. The comments from the participants mainly ealt with sample elivery an participants reporting errors. The comments from the provier are mainly focuse to the lacking conversancy to the given information with the samples. All the feeback is valuable an is exploite when improving the activities. 2.6 Processing the ata Pretesting the ata The normality of the ata was teste by the Kolmogorov-Smirnov test. The outliers were rejecte accoring to the Grubbs or Hampel test before calculating the mean. Also before the statistical results hanling some outliers were rejecte in cases, where the result iffere from the ata more than s rob 5 or 50 % from the robust mean or the result was reporte erroneously (e.g. wrong unit). The rejection of results was partly base to the rather strict requirements for the reproucibility given in the stanars for analysis escribe in the covering letter of the samples. The uplicate results were teste using the Cochran test. If the result was reporte lower than etection limit, it has not been inclue in calculations. Proftest SYKE CAL 07/17 9

12 More information about the statistical hanling of the ata is available in the Guie for participant [4] Assigne values Mainly the robust mean of the participants results was use as the assigne value for measurements of the test samples, when there were at least 12 results (n(stat) 12). In calculation of the robust mean the outliers are normally not rejecte, but they are iterate before the final calculation of the robust mean (Appenix 6). However, in this proficiency test some extreme results were consiere as clear outliers an thus rejecte. Also the mean an the meian values of the ata were calculate an they were quite similar to the assigne values (Table 1). In cases, where the number of results was lower than 12, the mean value of the participants results was use as the assigne value (the peat sample B1: all measurans; the sample B2: C, H, N, q p,net,, V p ; the sample K1: H, N, V p ). Assigne value was given neither for analysis moisture content M a, (all samples) nor for hyrogen, H, in the peat sample (B1, high eviation of the results). For nitrogen, N, in the pellet sample (B2) the informative assigne value is given, but ue to the high eviation of the results the performance evaluation was not one. In cases, where the number of results was less than 6 (n(stat)<6), the performance evaluation was one using E n score, if the assigne value an its measurement uncertainty was set (C, EF, an N in the peat sample B1). When the robust mean was use as the assigne value, the expane measurement uncertainty was calculate using the robust stanar eviation. When the mean value was use as the assigne value, the expane measurement uncertainty was estimate base on the stanar eviation [2, 4]. When using the robust mean or mean of the participant results as the assigne value, the stanar uncertainties of the assigne values for calorific values were between 0.1 % an 0.4 %. For the other evaluate measurans the uncertainty varie from 0.4 % to 10 % (Appenix 5). The participants also calculate emission factors (EF) for the peat (B1) an coal (K1) samples accoring to the given total moisture contents as receive (M ar ). In this PT, very few participants reporte their results for the emission factor (4-8). Due to the low number of the reporte results the peat sample (B1) was evaluate base on E n score. The results for analysis moisture content (M a, ) have not been evaluate ue to high eviation in the results, but the assigne values are shown. The results of nitrogen in the woo pellet sample have not been evaluate ue to high eviation of the results an low concentration level, but the assigne values are shown (Table 1). After reporting the preliminary results no changes have been one for the assigne values. 10 Proftest SYKE CAL 07/17

13 2.6.3 Stanar eviation for proficiency assessment an results evaluation The requirements for the reproucibility of the use stanar methos were reporte in the cover letter of the samples an they were use for estimation of stanar eviation for proficiency assessment in this PT. The reproucibility require for the stanar methos was mainly fulfille for gross calorific values. The stanar eviation for the proficiency assessment (2 s pt at the 95 % confience level) was set to 1 30 % epening on the measurements. After reporting the preliminary results no changes have been one for the stanar eviations of the proficiency assessment values. Aitionally, when the number of reporte results was low an the uncertainty was set for the assigne value, an the participant reporte measurement uncertainty, the performance was estimate by means of E n scores ( Error, normalize, Appenix 9). These are use to evaluate the ifference between the assigne value an participant s result within their claime expane uncertainty. E n scores are calculate: ( ) =, where x i = participant s result, x pt = assigne value, U i = the expane uncertainty of a participant s result an U pt = the expane uncertainty of the assigne value. E n scores of -1.0 < E n < 1.0 shoul be taken as an inicator of successful performance when the uncertainties are vali. Whereas scores E n 1.0 or E n -1.0 coul inicate a nee to review the uncertainty estimates, or to correct a measurement issue. The reliability of the assigne values was teste accoring to the criterion u pt / s pt 0.3, where u pt is the stanar uncertainty of the assigne value an s pt is the stanar eviation for proficiency assessment [2, 3]. When testing these reliabilities the criterion was mainly fulfille an the assigne values were consiere reliable. The reliability of the target value of the stanar eviation an the corresponing was estimate by comparing the eviation for proficiency assessment (s pt ) with the robust stanar eviation (s rob ) or stanar eviation (s) of the reporte results [3]. The criterion s rob (or s)/ s pt < 1.2 was mainly fulfille. In the following case, the criteria for the reliability of the assigne value an for the reliability of the target value for the eviation were not met an, therefore, the evaluation of the performance is reuce in this proficiency test: Sample B1 Measuran Ash Proftest SYKE CAL 07/17 11

14 3 Results an conclusions 3.1 Results The summary of the results of this proficiency test is presente in Table 1. Explanations to terms use in the result tables are presente in Appenix 6.The results an the performance of each participant are presente in Appenix 7. The reporte results with their expane uncertainties (k=2) are presente in Appenix 8. The summaries of the z an E n scores are shown in Appenix 9 an the s in the ascening orer in Appenix 10. The robust stanar or stanar eviations of the results varie from 0.3 to 30.7 % (Table 1). The robust stanar or stanar eviation was lower than 2 % for 52 % of the results an lower than 6 % for 87 % of the results (Table 1). For M a the robust stanar eviation of the results was higher than 6 % (B1) an for N it was the highest 30.7 % (B2, Table 1). The robust stanar or stanar eviations were approximately within the same range as in the previous similar proficiency test Proftest SYKE 8/2016, where the eviations varie from 0.3 % to 59 % [5]. Table 1. The summary of the results in the proficiency test 07/2017. Measuran Sample Unit Assigne value Mean Rob. mean Meian SD rob SD rob % 2 x spt % n (all) Acc z % Ash B1 w% B2 w% K1 w% C B1 w% B2 w% K1 w% EF B1 t CO2/TJ K1 t CO2/TJ H B1 w% B2 w% K1 w% Ma, B1 w% B2 w% K1 w% N B1 w% B2 w% K1 w% qp,net, B1 J/g B2 J/g K1 J/g qv,gr, B1 J/g B2 J/g K1 J/g S B1 w% K1 w% Vb B1 w% B2 w% K1 w% Rob. mean: the robust mean, SD rob: the robust stanar eviation, SD rob %: the robust stanar eviation as percent, 2 s pt %: the stanar eviation for proficiency assessment at the 95 % confience level, Acc z %: the results (%), where z 2, n(all): the total number of the participants. 12 Proftest SYKE CAL 07/17

15 In this proficiency test the participants were requeste to report replicate results for all measurements. The results of the replicate eterminations base on the ANOVA statistics are presente in Table 2. The international stanars or technical specifications relate to the measurements of fuels, recommen the targets for the repeatability. In particular, in measurements of the calorific values, the requirement for the repeatability is ± 120 J/g. In this proficiency test the requirements for the repeatability of the measurements of the gross calorific value were 0.54 % for the sample B1, 0.59 % for the sample B2 an 0.41 % for the sample K1 an in measurement of the net calorific value 0.57 %, 0.64 % an 0.42 %, respectively. In each case, the obtaine repeatability of the measurement of the gross calorific value an the net calorific value was lower than the repeatability requirement (Table 2, the column s w %). Table 2. The summary of repeatability on the basis of replicate eterminations (ANOVA statistics). Measuran Sample Unit Assigne value Mean sw sb st sw% sb% st% sb/sw Ash B1 w% B2 w% K1 w% C B1 w% B2 w% K1 w% EF B1 t CO2/TJ K1 t CO2/TJ H B1 w% B2 w% K1 w% Ma, B1 w% B2 w% K1 w% N B1 w% B2 w% K1 w% qp,net, B1 J/g B2 J/g K1 J/g qv,gr, B1 J/g B2 J/g K1 J/g S B1 w% K1 w% Vb B1 w% B2 w% K1 w% Ass.val.: assigne value; s w : repeatability stanar error; s b : between participants stanar error; s t : reproucibility stanar error. Proftest SYKE CAL 07/17 13

16 The estimation of the robustness of the methos coul be one by the ratio s b /s w. The ratio s b /s w shoul not excee the value 3 for robust methos. Here, however, the robustness exceee the value 3 in many cases (Table 2). For the gross calorific value, the ratio s b /s w, was 6.5 (the sample B1), 3.5 (the sample B2) an 2.2 (the sample K1), for the net calorific values 4.3, 3.4 an 3.2, respectively. For the calorific values the ratio s b /s w was mainly within the same range than in the previous similar proficiency test CAL 08/2016, with the exception of somewhat higher ratio for the gross calorific value in the coal sample (K1) [5]. 3.2 Analytical methos The participants were allowe to use ifferent analytical methos for the measurements in the PT. A questionnaire of some etaile information relate to the use analytical methos was provie along the proficiency test. The summary of the answers is shown in Appenix 11. The use analytical methos an the results of the participants groupe by methos are shown in more etail in Appenix 12. The statistical comparison of the analytical methos was possible for the ata where the number of the results was 5. However, in this PT there were not enough results for statistical comparison. Thus, the comparison is base on the graphical result evaluation Gross an net calorific value The analytical methos base on ifferent stanar methos were use for the measurements in the proficiency test. The use analytical methos of the participants are shown in more etail in Appenix 12. Mostly, stanar methos were use for measurement of calorific value (EN [6], ISO 1928 [7], Appenix 11). Two participants use other stanar (EN 15400, participants 9, 17) an one reporte to use isoperibolic calorimeter (participant 12). In the calculations of gross calorific value (q V,gr, ), various correction factors were use. Fuse wire, ignition, aci, moisture, nitrogen an sulphur corrections were most commonly use in several ifferent combinations epening of the test material (Appenix 11). For the calculation of net calorific value (q p,net, ), ifferent combinations of correction factors were use as well epening of the test material (Appenix 11). Mainly nitrogen plus oxygen (N+O) an hyrogen (H) content was use for corrections. Base on the graphical result evaluation, clear ifferences between the use methos in gross an net calorific value measurements coul not be conclue. 14 Proftest SYKE CAL 07/17

17 3.2.2 Measurement of carbon, hyrogen, nitrogen, sulphur, moisture, ash an volatile matter In the proficiency test the following several stanar methos or technical specifications were mainly use for measurements of ifferent parameters: Measuran Metho C, H an N ISO [8], ASTM D 5373 [9], EN ISO [10] S ISO 334 [11], EN ISO [12], ASTM D 4239 [13] Analytical moisture content EN [14], ISO 589 [15], DIN [16], ASTM D 7582 [17], ASTM D 5142 [18], EN ISO [19], ISO [20] Ash content EN [21], ISO 1171 [22], ASTM D 7582 [17], ASTM D 5142 [18], EN ISO [23] Volatile matter EN [24], ISO 562 [25], EN ISO [26] However, in some cases also other international an national stanars or technical specifications (e.g. ISO 19579, EN 15403, CEN/TS ) or internal methos (e.g. participants 1, 6, 10-13, 16, 17, 21) were use. Moisture content was mainly etermine gravimetrically by heating in air or N 2 atmosphere at the temperatures of C. Moisture content was measure also using TGA at the temperatures of 105 C. Air an N 2 atmosphere was use for etermining moisture content for coal samples. One participant use nitrogen atmosphere for the peat an woo pellet sample (Appenix 11). The ash content was etermine mainly gravimetrically by heating at the temperature 550 C or 815 C (Samples B1, B2) or at the temperature 815 C (Sample K1). Ash content was measure also using TGA for samples at the temperatures between 550 C an 815 C (Appenix 11). In the international stanars EN [21] an EN ISO [23] the ashing temperature is mentione to be 550 C an in ISO 1711 [22] it is mentione to be 815 C. Base on the graphical result evaluation, clear ifferences between the use methos in measurements coul not be conclue. Most of the participants conucte CHN analyses from air rie samples, an from rie samples one participant for the sample B1, four participants for the sample B2 an three participants for the sample K1 (Appenix 11). In the proficiency test also information of etection limit of nitrogen an sulphur was collecte (Appenix 11). 3.3 Uncertainties of the results At maximum 54 % of the participants reporte the expane uncertainties (k=2) with their results for at least some of their results (Table 3, Appenix 13). The range of the reporte uncertainties varie between the measurements an the sample types. Several approaches were use for estimating of measurement uncertainty (Appenix 13). The most use approach was base on metho valiation ata. Two participants reporte the usage of the MUkit measurement uncertainty software for the estimation of their uncertainties [27]. Proftest SYKE CAL 07/17 15

18 The free software is available in the webpage: Generally, the use approach for estimating measurement uncertainty i not make efinite impact on the uncertainty estimates. Table 3. The range of the expane measurement uncertainties (k=2, U i %) reporte by the participants. Measurement Uncertainty B1,% Uncertainty B2, % Uncertainty K1, % Ash C EF H N qp,net, qv,gr, S Vb The estimate uncertainties varie highly for all the teste measurements (Table 3). Especially, very low or high uncertainties can be consiere questionable. It was evient, that some uncertainties ha been reporte erroneously for the measurans (incluing calorific values, Appenix 13), not as relative values as the provier of this proficiency test ha requeste. It is evient that the harmonization is still neee for the estimation of the expane measurement uncertainties. 3.4 Estimation of emission factor Aitionally, the participants were aske to estimate the emission factors for the peat an coal samples istribute in the proficiency test by taking into account their own net calorific values an the total moisture values as receive, which was informe in the cover letter of the samples. The calculation of the emission factor of the woo pellet sample (B2) was not one as it is a CO 2 neutral fuel. In this PT, very few participants reporte their results for the emission factor (4-8). Due to the low number of the reporte results, the peat sample (B1) was evaluate base on E n score (Appenix 9). 4 Evaluation of the results The evaluation of participants was base on the s an E n scores, which were interprete as follows: Criteria Performance z 2 Satisfactory 2 < z < 3 Questionable z 3 Unsatisfactory -1.0 < En < 1.0 Satisfactory En or En 1.0 Unsatisfactory 16 Proftest SYKE CAL 07/17

19 Table 4. Summary of the performance evaluation in the proficiency test 07/2017. Sample Satisfactory Accepte eviation from Remarks results (%) the assigne value (%) Peat, B Very goo performance. Only approximate assessment for Ash. In the CAL 08/16 the performance was satisfactory for 82 % of the results [5]. Woo pellet, B Difficulties in measurements for C, < 80% satisfactory results. In the CAL 08/16 the performance was satisfactory for 85 % of the results [5]. Coal, K Difficulties in measurements for Vb, < 80% satisfactory results. In the CAL 08/16 the performance was satisfactory for 91 % of the results [5]. In total, 89 % of the results evaluate base on s were satisfactory (Appenix 9) when accepting eviation of 1 30 % from the assigne value. All results evaluate base on E n scores were satisfactory (Appenix 9). About 77 % of the participants use the accreite methos an 93 % of their results were satisfactory. In the previous similar proficiency test CAL 08/2016 the performance was satisfactory for 90 % of the results when eviation 1 30 % from the assigne value was accepte [5]. The summary of the performance evaluation is shown in Table 4. The percentage of the satisfactory results varie between 85 % an 100 % for the teste sample types. The criteria for performance ha been mainly set accoring to the target value for reproucibility recommene in international stanars or technical specifications for measurement of the calorific values an other eterminants. The reproucibility require in the stanars was fulfille for the gross calorific values. For the net calorific value increase reproucibility from the value for the gross caloric value was use. There was no criterion for reproucibility for the net calorific value in stanars methos. Peat In the previous similar proficiency test CAL 08/2016 the satisfactory results of the peat sample (B1) were in total 82 % [5], thus the performance in this PT is much better than previous (100 %, Table 4). The number of satisfactory results of the gross an net calorific values for woo pellet was higher for the gross calorific value an the net calorific value than in the previous proficiency test CAL 08/16 (82 % an 93 % respectively) [5]. The results of analysis moisture (M a ) have not been evaluate, but the assigne values are presente (Table 1). The results of C, EF, N were evaluate base on the E n scores, which were all satisfactory (Appenix 9). Woo pellet In the previous similar proficiency test CAL 08/2016 the satisfactory results of the woo pellet sample (B2) were in total 85 % [5], thus the performance in this proficiency test was the same (Table 4). The satisfactory results varie between 75 % (C ) an 91 % (H ) for the woo pellet Proftest SYKE CAL 07/17 17

20 sample (Table 1). In the measurement of gross an net calorific values 83 % of the results were satisfactory when accepting eviations of 1.5 % an 1.7 % from the assigne values (Table 1). The number of satisfactory results of the gross an net calorific values for woo pellet was higher for gross calorific value an somewhat lower for the net calorific value than in the previous proficiency test CAL 08/16 (75 % an 86 % respectively) [5]. The estimation of EF was not one as it is a CO 2 neutral fuel. Also the results of analysis moisture (M a ) an nitrogen (N ) have not been evaluate, but the assigne value is given (Table 1). Coal In the previous similar proficiency test CAL 08/2016 the satisfactory results of the coal sample (K1) were in total 91 % [5], thus the performance was somewhat lower in this PT (88 %, Table 4). In the measurement of gross an net calorific values, 94 % an 92 % of results, respectively, were satisfactory, when accepting the eviations of 1 an 1.1 % from the assigne values (Table 1). The calculate emission factor results were all satisfactory. In this proficiency test the number of satisfactory result of the gross an net calorific values were higher than in the previous test CAL 08/16 (85 % an 84 %, respectively) [5]. The results of analysis moisture (M a ) have not been evaluate, but the assigne value is given (Table 1). 5 Summary Proftest SYKE carrie out the proficiency test (PT) for the analysis of the gross an the net calorific value as well as for content of ash, carbon, hyrogen, nitrogen, sulphur, analytical moisture content an volatile matter in fuels in September Three types of samples were elivere to the participants: peat, woo pellet (not sulphur) an coal. In total 26 participants took part in the PT. Aitionally, the participants were aske to estimate or calculate the emission factor for peat an coal samples. The robust means (or means, n<12) of the results reporte by the participants were use as the assigne values for measurements. The uncertainty for the assigne value was estimate at the 95 % confience interval an it was less than 0.5 % for calorific values an at maximum 10 % for the other measurements. The evaluation of the performance was base on the s, which were calculate using the stanar eviation for proficiency assessment at 95 % confience level. In cases where the number of the results was low, the performance was estimate by using E n scores (C, EF, N in the peat sample). The evaluation of performance was not one for the measurement of M a in all samples, H in the peat sample an N in the woo pellet sample. In this proficiency test 89 % of the ata was regare to be satisfactory when the result was accepte to eviate from the assigne value from 1 to 30 %. About 77 % of the participants use accreite methos an 93 % of their results were satisfactory. In measurements of the gross calorific value from peat, woo pellet an coal samples, 100 %, 83 % an 94 % of the results were satisfactory, respectively. In measurements of the net calorific value from the peat, woo pellet an coal samples, 100 %, 83 % an 92 % of the results were satisfactory, respectively. In general, the 18 Proftest SYKE CAL 07/17

21 results were in the same range as in the previous similar Proftest SYKE proficiency test in CAL 08/2016 [5], but the performance in the gross calorific value was higher for peat, woo pellet an coal samples an also for the net calorific value for peat an coal samples in the present PT. For woo pellet sample the performance of the net calorific was somewhat lower in the present PT. The evaluation of ata base on E n scores show satisfactory performance for all results. 6 Summary in Finnish Proftest SYKE järjesti syyskuussa 2017 pätevyyskokeen kalorimetrisen ja tehollisen lämpöarvon sekä tuhkan, veyn, typen, rikin, kosteuen ja haihtuvien yhisteien määrittämiseksi turpeesta, puupelletistä (ei rikkiä) ja kivihiilestä. Lisäksi osallistujilla oli mahollisuus laskea päästökerroin turve- ja kivihiilinäytteistä. Pätevyyskokeeseen osallistui yhteensä 26 laboratoriota. Osallistujien pätevyyen arviointi tehtiin z-arvon avulla ja sen laskemisessa käytetyn kokonaishajonnan tavoitearvot olivat määrityksestä riippuen välillä 1 30 %. Turvenäytteen hiili, typpi ja päästökerroin arvioitiin käyttäen E n -arvoa tulosten vähyyen vuoksi. Testisuureen vertailuarvona käytettiin osallistujien ilmoittamien tulosten robustia keskiarvoa tai keskiarvoa, jos tuloksia oli vähän (n<12). Tavoitearvon epävarmuus oli lämpöarvomäärityksissä alhaisempi kuin 0,5 % ja muien määritysten osalta korkeintaan 10 %. Tulosten arviointia ei tehty testinäytteien kosteuspitoisuuen määritykselle, veyn määritykselle turpeesta ja typen määritykselle puupelletistä. Koko tulosaineistossa hyväksyttäviä tuloksia oli 89 %, kun vertailuarvosta sallittiin 1 30 % poikkeama. Noin 77 % osallistujista käytti akkreitoituja määritysmenetelmiä ja näistä tuloksista oli hyväksyttäviä 93 %. Kalorimetrisen lämpöarvon tuloksista oli hyväksyttäviä 100 % (turve), 83 % (puupelletti) ja 94 % (kivihiili). Tehollisen lämpöarvon tuloksille vastaavat hyväksyttävien tulosten osuuet olivat 100 % (turve), 83 % (puupelletti) ja 92 % (kivihiili). Hyväksyttäviä tuloksia oli lähes saman verran kuin eellisessä vastaavassa pätevyyskokeessa CAL 08/2016 [5]. Turve-, pelletti- ja hiilinäytteien osalta kalorimetrisen lämpöarvon sekä turve- ja hiilinäytteien osalta tehollisen lämpöarvon määrityksissä menestyminen oli parempaa kuin eellisellä kierroksella. Pellettinäytteen osalta tehollisen lämpöarvon määrityksessä menestyminen oli jonkin verran heikompaa kuin eellisellä kierroksella. E n -arvolla arvioiut tulokset olivat kaikki hyväksyttäviä. Proftest SYKE CAL 07/17 19

22 REFERENCES 1. SFS-EN ISO 17043, Conformity assessment General requirements for Proficiency Testing. 2. ISO 13528, Statistical methos for use in proficiency testing by interlaboratory comparisons. 3. Thompson, M., Ellison, S. L. R., Woo, R., The International Harmonize Protocol for the Proficiency Testing of Analytical Chemistry laboratories (IUPAC Technical report). 4. Proftest SYKE Guie for laboratories: Running proficiency test ( 5. Leivuori, M., Rantanen, M., Koivikko, R., Tervonen, K., Lanteri, S., Ilmakunnas, M., Proficiency test 08/2016. Gross an net calorific value in fuels. Reports of Finnish Environment Institute 45/ pp. ( 6. EN 14918, Soli Biofuels. Metho for the etermination of calorific value. 7. ISO 1928, Soli mineral fuels - Determination of gross calorific value by a bomb calorimetric metho, an calculation of net calorific value. 8. ISO 29541, Soli mineral fuels - Determination of total carbon, hyrogen an nitrogen content - Instrumental methos. 9. ASTM D 5373, Stanar Test Methos for Instrumental Determination of Carbon, Hyrogen, an Nitrogen in Laboratory Samples of Coal an Coke. 10. EN ISO 16948, Soli biofuels - Determination of total content of carbon, hyrogen an nitrogen. 11. ISO 334, Soli mineral fuels - Determination of total sulfur - Eschka metho. 12. EN ISO 16994, Soli biofuels - Determination of total content of sulfur an chlorine. 13. ASTM D 4239, Stanar Test Methos for Sulfur in the Analysis Sample of Coal an Coke Using High - Temperature Combustion an Infrare Absorption. 14. EN , Soli biofuels. Methos for the etermination of moisture content. Oven ry metho. Part 3: Moisture in general analysis sample (withrawn). 15. ISO 589, Har coal - Determination of total moisture. 16. DIN 51718, Determining the moisture content of soli fuels. 17. ASTM D 7582, Stanar Test Methos for Proximate Analysis of Coal an Coke by Macro Thermogravimetric Analysis. 20 Proftest SYKE CAL 07/17

23 18. ASTM D 5142, Stanar Test Methos for Proximate Analysis of the Analysis Sample of Coal an Coke by Instrumental Proceures (withrawn). 19. EN ISO 18134, Soli biofuels - Determination of moisture content - Oven ry metho - Part 3: Moisture in general analysis sample. 20. ISO 11722, Soli mineral fuels - Har coal - Determination of moisture in the general analysis test sample by rying in nitrogen. 21. EN 14775, Soli biofuels. Determination of ash content (withrawn). 22. ISO 1171, 2010 Soli mineral fuels - Determination of ash. 23. EN ISO 18122, Soli biofuels - Determination of ash content. 24. EN 15148, Biofuels, Soli fuels, Biomass, Fuels, Chemical analysis an testing, Volatile matter etermination, Gravimetric analysis (withrawn). 25. ISO 562, Har coal an coke - Determination of volatile matter. 26. EN ISO 18123, Soli biofuels -- Determination of the content of volatile matter. 27. Näykki, T., Virtanen, A. an Leito, I., Software support for the Nortest metho of measurement uncertainty evaluation. Accre. Qual. Assur. 17: Mukit website: Magnusson, B. Näykki. T., Hovin, H. an Krysell, M., Hanbook for Calculation of Measurement Uncertainty in Environmental Laboratories. NT Technical Report 537. Nortest. 29. Ellison, S., L., R. an Williams, A. (Es). (2012) Eurachem/CITAC guie: Quantifying Uncertainty in Analytical Measurement, Thir eition, ISBN ISO/IEC Guie 98-3:2008. Uncertainty of measurement - Part 3: Guie to the expression of uncertainty in measurement (GUM: 1995). Proftest SYKE CAL 07/17 21

24 APPENDIX 1 (1/1) APPENDIX 1: s in the proficiency test Country Bulgary Estonia Finlan France Lithuania Institute AES-3C Maritza East 1 EOOD; Testing Laboratory "Energy Materials" Enefit Energiatootmine AS Chemical Laboratory Ahma ympäristö Oy, Oulu Eurofins Environment Testing Finlan Oy, Vantaa, Inustry an Power Plant Chemistry Finnsementti Oy Fortum Waste Solutions Oy, Riihimäki Kymen Ympäristölaboratorio Oy Kymenlaakson ammattikorkeakoulu Labtium Oy, Jyväskylä Luonnonvarakeskus Kokkolan laboratorio ArcelorMittal Fos sur Mer SOCOR Dechy France AB "Siauliu Energija" chemijos laboratorija, Siauliai, Lithuania Republic of Irelan Eenerry Power Lt Republic of Korea Romania Spain Sween Komipo, Boryeong Thermal Power Site Division The Founation of Agr. Tech. Commercialization an Transfer Air Pollution Laboratory- INCD ECOIND- Bucuresti- Romania Ceprocim S.A. Romania CRH Ciment (Romania)-Punct e lucru Hoghiz Holcim Romania - Ciment Ales Holcim(Romania) SA Ciment Campulung INCDE ICEMENERG Bucharest, National Research an Development Institute for Energy Laborator analize fizico-chimice apa si carbune, Romania ROMPETROL QUALITY CONTROL SRL-Laborator Prouse Petroliere Laboratorio Central e Calia - LCC RISE Research Institutes of Sween AB 22 Proftest SYKE CAL 07/17

25 APPENDIX 2 (1/2) APPENDIX 2: Preparation of the samples Sample B1, peat Sample B1 was prepare from peat taken from Finnish marshlan. The peat was air-rie (35 ºC) an groune in a mill with a 500 µm sieve at the laboratory of Labtium. The rie an sieve sample was mixe by a mechanize sample mixer an istribute to sub-samples of ca. 30 g using a rotary sample ivier equippe with a vibratory sample feeer at the laboratory of Water Protection Association of the Kokemäenjoki River. The particle size istribution of peat was measure by the laboratory of Labtium using laser iffraction (Malvern). Sample B2, woo pellet The sample B2 was provie by Vapo an it was prepare from spruce sawust. The woo pellets were first crushe with a cutting mill an then groune by the mill with 1000 µm sieve at the laboratory of Labtium. The sieve sample was mixe by a mechanize sample mixer an istribute to subsamples of ca. 30 g using a rotary sample ivier equippe with a vibratory sample feeer at the laboratory of Water Protection Association of the Kokemäenjoki River. Sample K1, coal Sample K1 was har coal. The coal was rie at room temperature an groune to particle size < 212 µm at the Helen Lt. The rie an sieve sample was mixe by a mechanize sample mixer an istribute into subsamples of ca. 30 g using a rotary sample ivier equippe with a vibratory sample feeer at the laboratory the laboratory of Water Protection Association of the Kokemäenjoki River. The particle size istribution of coal was measure by the Helen Lt using laser iffraction (Malvern). Proftest SYKE CAL 07/17 23

26 APPENDIX 2 (2/2) Particle size To test the particle size of peat (B1) an coal (K1) samples teste using laser iffraction (Malvern). Figure 1 is showing the istribution of particle size for the samples B1 an K1. For peat sample B1 the mean size of particles was 87 µm an ca. 98 % of the particles were smaller than 550 µm. For coal sample K1 the mean size of particles was 57.8 µm an 94.9 % of the particles were smaller than 212 µm. The requirements of particle sizes given in the international stanars were not totally fulfille for the teste material [6, 7]. However, base on the results of the PT this seeme not to have influence the performance of the participants. a) The particle size istribution of peat B1. b) The particle size istribution of coal K1. Figure 1. The particle size istribution of the fuel samples a) the peat (B1) an b) the coal (K1) sample. 24 Proftest SYKE CAL 07/17

27 APPENDIX 3 (1/1) APPENDIX 3: Homogeneity of the samples Homogeneity was teste from uplicate measurements of calorific value (Table 1) an ash content in five samples, which were homogenise before sampling. Aitionally, the other measurans from two samples was teste. Criteria for homogeneity: s anal /s h <0.5 an s sam 2 <c, where s h % = stanar eviation for testing of homogeneity s anal = analytical eviation, stanar eviation of the results within sub samples s pt % = stanar eviation for proficiency assessment s sam = between-sample eviation, stanar eviation of the results between sub samples c = F1 s all 2 + F2 s anal 2, where s all 2 = (0.3 s h ) 2, F1 an F2 are constants of F istribution erive from the stanar statistical tables for the teste number of samples [2, 3]. Table 1. Results from the homogeneity testing for the calorific values of the peat (B1), pellet (B2) an coal (K1) samples. Measurements Mean sh% spt% sh sanal sanal/sh Gross calorific value, J/g Net calorific value, J/g Gross calorific value, J/g Net calorific value, J/g Gross calorific value, J/g Net calorific value, J/g Peat (B1) Is sanal/sh<0.5? ssam ssam 2 c Is ssam 2 <c? yes yes yes yes Pellet (B2) yes yes yes yes Coal (K1) yes yes yes yes Conclusion: In each case, the criteria were fulfille. Thus, all the samples coul be regare as homogenous. Also the results of the other teste measurans confirm the homogenous. Proftest SYKE CAL 07/17 25

28 APPENDIX 4 (1/2) APPENDIX 4: Feeback from the proficiency test FEEDBACK FROM THE PARTICIPANTS Comments on technical execution Action / Proftest 7, 9, 18 The samples were not elivere irectly to the recipients, but to the elivery center by the istributor (Posti) 10 The participant informe that they i not receive the preliminary results. 14 The participants informe that the coal sample K1 was coarse an neee for further grining. All The sample arrival form was not available from the electronic client interface, ProftestWEB, after sample elivery. Comments to the results Action / Proftest 6 The participants informe that they reporte some results erroneously for coal sample (K1). The correcte results were: H: 4.75 an 4.74 w% Vp: an w% Also they reporte sulphur results for coal after reporting the preliminary results S: 0.32 an 0.32 w% 8 The participants informe that they reporte some results erroneously for coal sample (K1). The correcte results were: qp,net,: J/g qv,gr,: J/g 14 The participants informe that they reporte some results erroneously for peat sample (B1). The correcte results were: H: an w% The provier use the stanar postal parcel service instea of an express service. The provier regrets this situation, an seeks to avoi a similar kin of situation in the future. The preliminary results were elivere to the participants via on 2 n October, The report of the preliminary results was also uploae into the electronic client interface, ProftestWEB, on the same ay. The grain size istribution of the sample was measure an the sample i not totally fulfill the requirement of stanars. Base on the participants results the coarseness of the sample i not affect to the results. The provier attache the sample arrival form immeiately after the note. The provier regrets the situation an seeks to avoi similar kin of situation in the future. The results were outliers in the statistical treatment, an thus i not affect the performance evaluation. If the hyrogen an volatile organic compouns results ha been reporte correctly, the results for woul have been satisfactory. The participant can re-calculate the s accoring to the Guie for participants [4]. The results were outliers in the statistical treatment, an thus i not affect the performance evaluation. If the results ha been reporte correctly, the results woul have been satisfactory. The participant can re-calculate the s accoring to the Guie for participants [4]. The hyrogen results were not evaluate for the peat sample. 26 Proftest SYKE CAL 07/17