The quality of aviation fuel available in the United Kingdom Annual surveys 2009 to 2013 CRC project no. AV-18-14
THE QUALITY OF AVIATION FUEL AVAILABLE IN THE UNITED KINGDOM ANNUAL SURVEYS 2009 TO 2013 October 2015 Prepared by Garry Rickard 1 Published by ENERGY INSTITUTE, LONDON The Energy Institute is a professional membership body incorporated by Royal Charter 2003 Registered charity number 1097899 and COORDINATING RESEARCH COUNCIL, GEORGIA The Coordinating Research Council is a non-profit organization that directs the interaction between automotive/other mobility equipment and petroleum products 1 Intertek, Room 1068, A7 Building, Cody Technology Park, Farnborough, Hampshire, GU14 0LX (Garry.Rickard@Intertek. com, +44 (0)1252 397076).
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ABSTRACT This report jointly funded by the Coordinating Research Council and the Energy Institute (EI) and prepared by Intertek contains a summary of the data relating to the specification properties for AVTUR (Jet A-1) supplied in the United Kingdom (UK) during the years 2009 to 2013. The data are expressed in the form of histograms and mean values, which are graphically compared over the period 1986-2013. This report is the thirty-sixth in a series of survey reports. 3
CONTENTS Page 1 Introduction...10 2 Results...11 2.1 Tabulated data....11 2.2 Histograms and trend graphs for annual mean results....................... 11 2.3 Graphs of near specification trends for AVTUR produced from 1983 to 2013....11 3 Discussion............................................................ 12 3.1 Sample size...12 3.2 Total acidity...12 3.3 Aromatics...12 3.4 Total sulfur...13 3.5 Mercaptan sulfur...13 3.6 Distillation...13 3.7 Flash point....14 3.8 Density...14 3.9 Freezing point...14 3.10 Kinematic viscosity....15 3.11 Specific energy...15 3.12 Smoke point...15 3.13 Naphthalenes...15 3.14 Existent gum...15 3.15 Microseparometer...16 3.16 Particulate contamination...16 3.17 Saybolt colour...16 3.18 Particle counts....16 3.19 BOCLE....17 3.20 Near specification trends...17 4 Summary of changes and trends....18 4.1 Trend data....18 4.2 Significant changes in 2013....18 5 References....19 Annexes Annex A Results summaries...20 A.1 2009 Data from 608 batches of jet fuel representing 7 197 709 m 3...20 A.2 2010 Data from 491 batches of jet fuel representing 6 713 391 m 3...21 A.3 2011 Data from 765 batches of jet fuel representing 9 336 574 m 3...22 A.4 2012 Data from 1 204 batches of jet fuel representing 14 104 040 m 3. 23 A.5 2013 Data from 1 259 batches of jet fuel representing 14 921 609 m 3. 24 Annex B Figures....25 B.1 Total acidity...25 B.2 Aromatics....28 B.3 Total sulfur...31 B.4 Mercaptan sulfur...34 B.5 Distillation IBP...37 4
Contents continued Page B.6 Distillation 10 % recovery.... 40 B.7 Distillation 50 % recovery.... 43 B.8 Distillation 90 % recovery.... 46 B.9 Distillation FBP...49 B.10 Flash point...52 B.11 Density at 15 C....55 B.12 Freezing point...58 B.13 Kinematic viscosity at -20 C...61 B.14 Specific energy....64 B.15 Smoke point...67 B.16 Naphthalenes....70 B.17 Existent gum...73 B.18 MSEP...76 B.19 Particulate (gravimetric)... 79 B.20 Saybolt colour...82 B.21 Particle counts...85 B.22 Near specification limit trend analysis...101 5
LIST OF FIGURES AND TABLES FIGURES Page Figure 1 Total acidity histogram 2009...25 Figure 2 Total acidity histogram 2010...25 Figure 3 Total acidity histogram 2011...26 Figure 4 Total acidity histogram 2012...26 Figure 5 Total acidity histogram 2013...27 Figure 6 Total acidity trend graph...27 Figure 7 Aromatics histogram 2009...28 Figure 8 Aromatics histogram 2010...28 Figure 9 Aromatics histogram 2011...29 Figure 10 Aromatics histogram 2012...29 Figure 11 Aromatics histogram 2013...30 Figure 12 Aromatics trend graph....30 Figure 13 Total sulfur histogram 2009....31 Figure 14 Total sulfur histogram 2010....31 Figure 15 Total sulfur histogram 2011....32 Figure 16 Total sulfur histogram 2012....32 Figure 17 Total sulfur histogram 2013....33 Figure 18 Total sulfur trend graph...33 Figure 19 Mercaptan sulfur histogram 2009...34 Figure 20 Mercaptan sulfur histogram 2010...34 Figure 21 Mercaptan sulfur histogram 2011...35 Figure 22 Mercaptan sulfur histogram 2012...35 Figure 23 Mercaptan sulfur histogram 2013...36 Figure 24 Mercaptan sulfur trend graph...36 Figure 25 Distillation IBP histogram 2009...37 Figure 26 Distillation IBP histogram 2010...37 Figure 27 Distillation IBP histogram 2011...38 Figure 28 Distillation IBP histogram 2012...38 Figure 29 Distillation IBP histogram 2013...39 Figure 30 Distillation IBP trend graph...39 Figure 31 Distillation 10 % recovery histogram 2009... 40 Figure 32 Distillation 10 % recovery histogram 2010... 40 Figure 33 Distillation 10 % recovery histogram 2011... 41 Figure 34 Distillation 10 % recovery histogram 2012... 41 Figure 35 Distillation 10 % recovery histogram 2013... 42 Figure 36 Distillation 10 % recovery trend graph.... 42 Figure 37 Distillation 50 % recovery histogram 2009... 43 Figure 38 Distillation 50 % recovery histogram 2010... 43 Figure 39 Distillation 50 % recovery histogram 2011... 44 Figure 40 Distillation 50 % recovery histogram 2012... 44 Figure 41 Distillation 50 % recovery histogram 2013... 45 Figure 42 Distillation 50 % recovery trend graph.... 45 Figure 43 Distillation 90 % recovery histogram 2009... 46 Figure 44 Distillation 90 % recovery histogram 2010... 46 Figure 45 Distillation 90 % recovery histogram 2011... 47 Figure 46 Distillation 90 % recovery histogram 2012... 47 Figure 47 Distillation 90 % recovery histogram 2013... 48 6
FIGURES CONTINUED Page Figure 48 Distillation 90 % recovery trend graph.... 48 Figure 49 Distillation FBP histogram 2009...49 Figure 50 Distillation FBP histogram 2010...49 Figure 51 Distillation FBP histogram 2011...50 Figure 52 Distillation FBP histogram 2012...50 Figure 53 Distillation FBP histogram 2013...51 Figure 54 Distillation FBP trend graph...51 Figure 55 Flash point histogram 2009...52 Figure 56 Flash point histogram 2010...52 Figure 57 Flash point histogram 2011...53 Figure 58 Flash point histogram 2012...53 Figure 59 Flash point histogram 2013...54 Figure 60 Flash point trend graph...54 Figure 61 Density histogram 2009....55 Figure 62 Density histogram 2010....55 Figure 63 Density histogram 2011....56 Figure 64 Density histogram 2012....56 Figure 65 Density histogram 2013....57 Figure 66 Density trend graph....57 Figure 67 Freezing point histogram 2009...58 Figure 68 Freezing point histogram 2010...58 Figure 69 Freezing point histogram 2011...59 Figure 70 Freezing point histogram 2012...59 Figure 71 Freezing point histogram 2013...60 Figure 72 Freezing point trend graph...60 Figure 73 Kinematic viscosity histogram 2009...61 Figure 74 Kinematic viscosity histogram 2010...61 Figure 75 Kinematic viscosity histogram 2011...62 Figure 76 Kinematic viscosity histogram 2012...62 Figure 77 Kinematic viscosity histogram 2013...63 Figure 78 Kinematic viscosity trend graph...63 Figure 79 Specific energy histogram 2009....64 Figure 80 Specific energy histogram 2010....64 Figure 81 Specific energy histogram 2011....65 Figure 82 Specific energy histogram 2012....65 Figure 83 Specific energy histogram 2013....66 Figure 84 Specific energy trend graph...66 Figure 85 Smoke point histogram 2009...67 Figure 86 Smoke point histogram 2010...67 Figure 87 Smoke point histogram 2011...68 Figure 88 Smoke point histogram 2012...68 Figure 89 Smoke point histogram 2013...69 Figure 90 Smoke point trend graph....69 Figure 91 Naphthalenes histogram 2009....70 Figure 92 Naphthalenes histogram 2010....70 Figure 93 Naphthalenes histogram 2011....71 Figure 94 Naphthalenes histogram 2012....71 Figure 95 Naphthalenes histogram 2013....72 Figure 96 Naphthalenes trend graph...72 Figure 97 Existent gum histogram 2009...73 7
Contents continued Page Figure 98 Existent gum histogram 2010...73 Figure 99 Existent gum histogram 2011...74 Figure 100 Existent gum histogram 2012...74 Figure 101 Existent gum histogram 2013...75 Figure 102 Existent gum trend graph...75 Figure 103 MSEP histogram 2009...76 Figure 104 MSEP histogram 2010...76 Figure 105 MSEP histogram 2011...77 Figure 106 MSEP histogram 2012...77 Figure 107 MSEP histogram 2013...78 Figure 108 MSEP trend graph...78 Figure 109 Particulate histogram 2009...79 Figure 110 Particulate histogram 2010...79 Figure 111 Particulate histogram 2011...80 Figure 112 Particulate histogram 2012...80 Figure 113 Particulate histogram 2013...81 Figure 114 Particulate trend graph...81 Figure 115 Saybolt colour histogram 2009...82 Figure 116 Saybolt colour histogram 2010...82 Figure 117 Saybolt colour histogram 2011...83 Figure 118 Saybolt colour histogram 2012...83 Figure 119 Saybolt colour histogram 2013...84 Figure 120 Saybolt colour trend graph...84 Figure 121 Particle counts 4 µm ISO code 2009...85 Figure 122 Particle counts 4 µm ISO code 2010...85 Figure 123 Particle counts 4 µm ISO code 2011...86 Figure 124 Particle counts 4 µm ISO code 2012...86 Figure 125 Particle counts 4 µm ISO code 2013...87 Figure 126 Particle counts 6 µm ISO code 2009...87 Figure 127 Particle counts 6 µm ISO code 2010...88 Figure 128 Particle counts 6 µm ISO code 2011...88 Figure 129 Particle counts 6 µm ISO code 2012...89 Figure 130 Particle counts 6 µm ISO code 2013...89 Figure 131 Particle counts 14 µm ISO code 2009...90 Figure 132 Particle counts 14 µm ISO code 2010...90 Figure 133 Particle counts 14 µm ISO code 2011...91 Figure 134 Particle counts 14 µm ISO code 2012...91 Figure 135 Particle counts 14 µm ISO code 2013...92 Figure 136 Particle counts 21 µm ISO code 2009...92 Figure 137 Particle counts 21 µm ISO code 2010...93 Figure 138 Particle counts 21 µm ISO code 2011...93 Figure 139 Particle counts 21 µm ISO code 2012...94 Figure 140 Particle counts 21 µm ISO code 2013...94 Figure 141 Particle counts 25 µm ISO code 2009...95 Figure 142 Particle counts 25 µm ISO code 2010...95 Figure 143 Particle counts 25 µm ISO code 2011...96 Figure 144 Particle counts 25 µm ISO code 2012...96 Figure 145 Particle counts 25 µm ISO code 2013...97 Figure 146 Particle counts 30 µm ISO code 2009...97 Figure 147 Particle counts 30 µm ISO code 2010...98 8
FIGURES CONTINUED Page Figure 148 Particle counts 30 µm ISO code 2011...98 Figure 149 Particle counts 30 µm ISO code 2012...99 Figure 150 Particle counts 30 µm ISO code 2013...99 Figure 151 Particle count trend graph...100 Figure 152 Near specification trend, acidity and aromatics.... 100 Figure 153 Near specification trend, mercaptans, flash point and freezing point... 101 Figure 154 Near specification trend, smoke point and naphthalenes... 101 TABLES Table 1 Properties where the mean value shows increasing or decreasing trends...18 Table 2 Significant changes in mean values...18 Table 3 Minima and maxima for 2009 data and specification limits...20 Table 4 Minima and maxima for 2010 data and specification limits...21 Table 5 Minima and maxima for 2011 data and specification limits...22 Table 6 Minima and maxima for 2012 data and specification limits...23 Table 7 Minima and maxima for 2013 data and specification limits...24 9
1 INTRODUCTION Surveys relating to the specification properties of aviation turbine fuels supplied in the UK from 1974 onwards have been published annually by The Fuels and Lubricants Centre 2 [1]-[24]. This report covers a similar survey for fuel (Jet A-1) supplied during the period 2009 to 2013 involving 4 327 batches complying with Defence Standard 91-91[25]. Historically, this survey was funded by the UK Ministry of Defence (MoD) in support of their specification development activities. In recent years, the EI has part-funded the work. However, after the 2008 survey was produced, the MoD ceased to fund the activity. In 2014, the EI funded the survey in full, in association with the Coordinating Research Council, and an effort was made to include as much data as possible since the last survey in 2008. The information contained in this report has been supplied by oil companies and associated test houses for main batches of aviation fuel released during 2009 to 2013. The data are expressed in the form of histograms and mean values, which are graphically compared over the period 1986 to 2013. Arithmetic mean values are not used due to the variation in volume of each fuel batch from which data points are gathered. Instead, the mean values are weighted according to the relative fuel volume associated with each data point. Historically most batches of jet fuel used for this survey were refined in the UK. However, over time many UK refineries have closed and more finished fuels were imported into the UK. Although the data provided do not give exact details on the number of imports, it is expected that a large proportion of the data in this report is from imported batches. Therefore, the data presented are likely to be at least partly representative of jet fuel available worldwide. The percentage of the results near to the specification limits are reported for selected properties. These properties were chosen for historical reasons (for comparisons with previous data) and include some properties which appear to limit jet fuel production. For the purposes of this report 'near specification limit' results are those that lie within the reproducibility of the method at the specification limit. The report also contains a short discussion on each property and how the results are changing. Results that are close to, or outside, specification limits are noted. Other points of interest such as the distribution of results are commented on. Changes and trends may be of interest and importance to specification writers, OEMs, users, and refiners and may be significant even though they do not approach current specification limits. It is expected that this report will be of most use for specification development and associated test method development. 2 The Fuels and Lubricants Centre (FLC) was originally part of the UK Ministry of Defence (MoD), which then became an Agency of the MoD under the names DRA and DERA. FLC then became part of QinetiQ and has been part of Intertek since 2011. 10
2 RESULTS The data reported have been abstracted from test certificates, or from electronic data supplied by oil companies, for new batches of AVTUR, either produced in, or imported into, the UK during the period 2009 to 2013. The data for all but four of the specification properties for AVTUR are summarised in tables and figures in the annexes. The data for copper corrosion and thermal stability were not included as the majority of results were identical. Copper corrosion results were typically 1A, with a number of 1B results and thermal stability results were typically a <1 tube rating with no pressure drop. All thermal stability results were reported at 260 C. Data for electrical conductivity were not included because at the point of testing, the conductivity of many batches was below the specified limits. This is permitted on the condition that static dissipater additive (SDA) is added further downstream [25] to ensure that the conductivity limits are met at the point of delivery into aircraft. 2.1 TABULATED DATA The tables given in the annexes provide the following information: Table 3 to Table 7 specification limits for each property from Defence Standard 91-91 compared to the maxima and minima of the 2009 to 2013 AVTUR data collected. 2.2 HISTOGRAMS AND TREND GRAPHS FOR ANNUAL MEAN RESULTS Figure 1 to Figure 151 are histograms and trend graphs. The histograms show the number of batches in each frequency class along with the percentage that this represents of the total number of batches included for that year. The trend graphs show the mean results for each property plotted against year for the period 1986 to 2013. Where the labels on the x-axis of the histograms refer to a range of results, the label signifies the middle of the range. For example, the x-axis label '10' on the aromatics histograms (Figure 7 to Figure 11) includes a range of results from >9 to 11. 2.3 GRAPHS OF NEAR SPECIFICATION TRENDS FOR AVTUR PRODUCED FROM 1983 TO 2013 For seven specification properties, Figure 152 to Figure 154 show the percentage of batches that have results near the specification limits, plotted against year for the period 1986 to 2013. The properties the figures relate to are listed here. Figure 152 acidity, aromatics. Figure 153 mercaptan sulfur, flash point, freeze point. Figure 154 smoke point, naphthalenes. 11
3 DISCUSSION This section is a brief discussion of the results highlighting significant changes and points of interest for the aviation industry. It also gives some details on the limitations of the data. The data for thermal stability, copper corrosion, and electrical conductivity are not discussed in this section for the reasons given in section 2. BOCLE results should be reported for all batches containing more than 95 % hydroprocessed material, of which at least 20 % is severely hydroprocessed. However, it was not possible to establish if a BOCLE test was required for many batches as the refining process was not supplied 3. No BOCLE results were reported for the batches used in this survey. 3.1 SAMPLE SIZE Data from 4 327 batches were included in this report which represents 52 273 323 m 3 of AVTUR over the period from the start of 2009 to the end of 2013. This includes more than 100 000 individual test results. The data in the tables and histograms for some properties have been derived from fewer than the total number of batches because the specification, for a variety of reasons, detailed below, allows waivers (and in some cases the data provided had a small number of results unavailable). 3.2 TOTAL ACIDITY The volume weighted mean value in 2013 was 0.0036 mg KOH/g and this has changed little compared in recent years (Figure 6). There is some evidence of multi-modal distribution. The percentage of batches 'near specification limit' has varied over the period of this report from 4.18 % to 11.93 % with no obvious trend. 3.3 AROMATICS The volume weighted mean value has varied between 15.7 % v/v to 18.8 % v/v from 2009 to 2013 (Figure 12). The lowest value was in 2009, which was the lowest value since records began in 1986. There was a smaller data set used for the survey for 2009 and 2010 and this may produce some skewing of results. However, the data sets remain very large. Aircraft operators are often concerned about the problems caused by different batches of fuel having large variations in aromatics. The aromatic content ranged from <5 % v/v to 25.0 % v/v with 99 % of batches in the range 13 % v/v to 25 % v/v. 3 It should be noted that some of the data supplied for this survey were not in the form of test certificates, but were supplied in spreadsheet format. These electronic data do not always give all the data that would be given on the main batch test certificate. This lack of detailed information does not mean that the original certificate did not contain the correct information, nor does it suggest that the fuel did not comply with the requirements of Defence Standard 91-91. 12
During 2009 and 2010 there were five batches reported as <5 % v/v. The test method used, IP 156, has a scope of 5 % v/v to 99 % v/v aromatic hydrocarbons. For the purposes of this report, the results were recorded as 5 % v/v for the histograms and mean calculations. 3.4 TOTAL SULFUR The volume weighted mean value from 2009 to 2013 has varied from 0.0047 % m/m to 0.055 % m/m (Figure 18). This is significantly lower than the high value of 0.077 % m/m seen in 2008. There appears to be an upward trend since 1999. However, the mean has been variable in recent years and it is difficult to determine any definite trend. The distribution of sulfur contents appears to show a multimodal distribution. Defence Standard 91-91 allows several different methods for determining sulfur content. Some laboratories are using methods that can determine the sulfur content to three decimal places, whereas when older equipment/different test methods are used, the result may only be reported to two decimal places. The most common test method used is IP 336 [26] which is reportable to the nearest 0.01 % m/m and the scope minimum is 0.03 % m/m. Therefore, many results are reported for batches with low sulfur contents as '<0.01 % m/m' and some as '<0.03 % m/m'. For the purposes of this report, the results have been recorded without the 'less than' sign (to be consistent with previous surveys). The differing methods mean that it is not possible to accurately determine the number of batches with very low sulfur levels. The methodologies used and the way in which the sulfur content is reported may have an effect on the apparent mean value. 3.5 MERCAPTAN SULFUR Mercaptan sulfur was reported for approximately three quarters of batches. Mercaptan sulfur is not required to be reported if the Doctor test is negative. A number of test certificates showed the mercaptan sulfur content as '<0.001'. (For the purposes of this survey, these results have always been recorded as 0.001). This may affect the volume weighted mean value, which varied from 0.0007 % mass to 0.0009 % mass during 2009 to 2013 (Figure 24). 3.6 DISTILLATION The mean value for initial boiling point (IBP) was 148.6 C and is the lowest recorded since 1986 (Figure 30). The mean values in 2013 for 10 % (167.7 C) (Figure 36), and 50 % (193.3 C) (Figure 42) recovered are also the lowest recorded. These three properties show a reducing trend. The 2013 mean value for 90 % recovered of 233.9 C is the lowest since 1986 but it is difficult to see a trend as the mean value has been variable in recent years (Figure 48). The final boiling point (FBP) mean has varied between 253.9 C and 260.8 C and no trend can be seen (Figure 54). Only 10 % recovered and FBP have limits specified, which are 205 C and 300 C respectively. All results were within these limits. 13
Aviation turbine fuels containing synthesized hydrocarbons in accordance with ASTM D7566 [27] have extended requirements (over ASTM D1655 and Defence Standard 91-91) to ensure a sufficient distillation range 4. The requirements are T50-T10, minimum of 15 C; and T90-T10 5, minimum of 40 C. Of the 1 259 batches in 2013, 10 would not have met the T50-T10 requirement and three would not have met the T90-T10 requirement. The raw data from this report could be used to check that the limits in D7566 are still relevant. 3.7 FLASH POINT The volume weighted mean value for flash point between 2009 and 2013 has varied from 41.4 C to 42.6 C (Figure 60). The 2013 value of 41.4 C is the lowest recorded since 1986 and there appears to be a reducing trend in the mean flash point since 1991. This trend is becoming less pronounced as the mean values approach the specification limit. 56 % of batches were 'near specification limit' in 2013. There appears to be a rising trend in the number of flash point results near the specification limit. A precision study in 2008 led to the reproducibility of IP 170 being changed from 1.5 C to 3.2 C. Although there has been a reduction in the mean and generally more batches near to the specification limit, the large changes seen in Figure 153 are mostly due to the change in reproducibility. The data indicate that flash point is a major restraining factor in jet fuel production. 3.8 DENSITY The volume weighted mean for density has varied from 799.9 kg/m 3 to 802.0 kg/m 3 over the period from 2009 to 2013 (Figure 66). The minimum density during 2009 to 2013 was 777.5 kg/m 3. The specification limits are 775 kg/m 3 to 840 kg/m 3. 3.9 FREEZING POINT The volume weighted mean value for 2013 of 55.0 C is the lowest value recorded since 1986 and there has been a slow downward trend since this time (Figure 72). The percentage of batches 'near specification limit' during 2009 to 2013 has varied from 3 % to 12 %. There appears to be a decreasing trend in the number of batches near the specification limit. However, freezing point appears to be a major restraining factor in jet fuel production for some refineries. Several batches were reported as <-60 C; these were recorded as -60 C for the purposes of this report. Two batches had reported freezing points of -46.0 C which are outside the specification requirement of -47 C maximum 6. 4 Although it is difficult to be certain due to the data received not being complete, with regard to refining processes, it is likely that few if any batches included in this survey contained synthetic components. 5 T10, T50, and T90 are the distillation temperatures at 10 %, 50 %, and 90 % recovered respectively. 6 No further information was received on the two batches outside the specification. However, after discussion with the producer it is thought very unlikely that out of specification fuel reached an aircraft. It is likely that the batch was blended to ensure that the final product was fit for use. 14
3.10 KINEMATIC VISCOSITY The volume weighted mean for 2013 was 3.66 cst, which is the lowest recorded since 1986 (Figure 78). There appears to be a reducing trend in mean viscosity and there has been a significant reduction since 2010. The specification limit is 8 cst maximum at -20 C. However, it should be noted that most aircraft engines are certified at 12 cst maximum at -40 C 7. This is approximately equivalent to 5.5 cst at -20 C. There were two batches in 2009 that exceeded 5.5 cst in 2009 and none from 2010 to 2013. 3.11 SPECIFIC ENERGY The volume weighted mean was 43.24 MJ/kg in 2013 and represents little change compared to recent years. Figure 84 shows no particular trend in mean value. Results are almost all between 43.0 MJ/kg and 43.5 MJ/kg. The specification minimum is 42.80 MJ/kg. 3.12 SMOKE POINT The volume weighted mean for 2013 was 23.3 mm. The smoke point specification limit is 19 mm minimum. The histograms show an unusual distribution with regard to the high percentage of results at 25 mm. This may be linked to the specification requirement for the measurement of naphthalenes when the smoke point is less than 25 mm. 3.13 NAPHTHALENES Not all batches had naphthalenes results reported as the specification only requires the determination of naphthalene content if the smoke point is less than 25 mm. The mean for 2013 was 1.16 % vol, the lowest ever recorded since records began in 1986. There appears to be a downward trend since 1988 (Figure 96). The specification limit is 3 % vol maximum. 3.14 EXISTENT GUM For more than 90 % of batches from 2009 to 2013, the existent gum results were reported as 0, <1, or 1 mg/100ml. For results reported as 0 or <1, a value of 1 has been recorded in the histograms. The 2013 mean value was 1.0 mg/100ml as shown in Figure 101. The precision for existent gum is very poor; it is likely that all batches contain virtually no gum and 7 The requirement for 12 cst is particularly relevant for APUs which may need to be started at altitude after cold soak conditions. Some APUs are flight critical. 15
the range of results (up to a maximum of 6 mg/100ml) is due to the test precision. The vast majority of the results are well below the 7 mg/100ml maximum specification limit. There is no significant trend in mean value for existent gum. 3.15 MICROSEPAROMETER The 2013 mean MSEP value of 94.5 has changed little compared to the previous few years (Figure 108). The Defence Standard 91-91 limitsfor MSEP rating is a minimum of 85 without SDA, or 70 with SDA due to the over sensitivity of the test method to SDA (Stadis 450). Some MSEP values during 2011, 2012, and 2013 were reported outside the specification limits. The reported failures may not be at the point of manufacture and downstream of this point a low MSEP is not used as the sole reason for rejection of a fuel. 3.16 PARTICULATE CONTAMINATION This is a relatively new requirement for Defence Standard 91-91 with a maximum limit of 1 mg/l. The 2013 volume weighted mean value of 0.29 is similar to that recorded in recent years (Figure 114). A number of batches did not include results for this property. Most of these batches were imported fuel and it is assumed that this testing was carried out at point of manufacture as required by the specification. No results outside the specification limit were reported. 3.17 SAYBOLT COLOUR This is a relatively new requirement for Defence Standard 91-91. The 2013 volume weighted mean value is 26.5 and changed little over the period from 2009 to 2013 (Figure 120). A number of batches did not include results for this property. Most of these batches were thought to be imported fuel and it is assumed that this testing was carried out at point of manufacture as required by the specification. 3.18 PARTICLE COUNTS Particle counts are recorded for the first time in this survey. For ease of producing histograms, ISO codes [28] have been used to indicate particle numbers 8. Histograms show the distribution of ISO codes for 4 µm, 6 µm, 14 µm, 21 µm, 25 µm, and 30 µm channels. For low particle counts (and low ISO codes) repeatability is poor and many labs report ISO codes below 7 as '<7'. For the purposes of this report any value of less than 7 was recorded as 7. The mean values are shown in Figure 151 over the period of 2009 to 2013. No trends are apparent. No specification limits for this property have been set at this time. 8 According to ISO 4406, codes are applicable to the 4 µm, 6 µm, and 14 µm channels. However, for the purposes of Defence Standard 91-91, codes are reported using the same ISO 4406 coding table, for all six channels. 16
3.19 BOCLE There were no BOCLE results reported from 2009 to 2013. 3.20 NEAR SPECIFICATION TRENDS Figure 152 to Figure 154 are graphs showing the percentage of batches with test results near the specification limit, against year, for seven specification properties. The properties with the highest percentage of batches with results near the specification limit in 2013 were flash point (56 %) and smoke point (33 %). It should be noted that the new precision for flash point (IP 170) has significant effects on the number of batches near specification limit as mentioned in 3.7. 17
4 SUMMARY OF CHANGES AND TRENDS 4.1 TREND DATA Table 1: Properties where the mean value shows increasing or decreasing trends Properties where the mean value has a rising trend Flash point batches near specification limit (increasing since 1991) Properties where the mean value has a decreasing trend Distillation IBP (decreasing since 1991) Distillation 10 % recovery (decreasing since 1991) Distillation 50 % recovery (decreasing since 2010) Flash point (decreasing since 1991) Freezing point batches near specification limit (decreasing since 1988) Viscosity (decreasing since 1991) Naphthalenes (decreasing since 1988) 4.2 SIGNIFICANT CHANGES IN 2013 Table 2: Significant changes in mean values Property Distillation, IBP Distillation, 10 % recovered Distillation, 50 % recovered Flash point Freezing point Viscosity Naphthalenes Change Down 2.2 C since 2009 (mean is at the lowest level since records began in 1986) Down 3.4 C since 2010 (mean is at the lowest level since records began in 1986) Down 4.0 C since 2010 (mean is at the lowest level since records began in 1986) Down 1.2 C since 2010 (mean is at the lowest level since records began in 1986) Down 3.1 C since 2011 (mean is at the lowest level since records began in 1986) Down 0.25 mm 2 /s since 2010 (mean is at the lowest level since records began in 1986) Down 0.37 % volume since 2010 (mean is at the lowest level since records began in 1986) 18
5 REFERENCES [1] Various MQAD and Harefield annual fuel surveys 1974-1986 [2] DQA/TS Materials Centre report No. 361, March 1987 [3] DQA/TS Technical report No. 88/2, May 1988 [4] DQA/TS Technical report No. 89/8, November 1989 [5] DQA/TS Technical report No. 91/4, March 1991 [6] DQA/TS Technical report No. 91/10, November 1991 [7] QATS FL Division Technical paper FLT/1/93, March 1993 [8] QATS FL Division Technical paper FLT/3/93, June 1993 [9] FVS FL Division Technical paper DRA/FVS/FL/TR94002/1, September 1994 [10] LS FL Division Technical paper DRA/LS/LSF4/TR95004, June 1995 [11] LS FL Division Technical paper DRA/LS4/TR96/044/1, July 1996 [12] SMC FL Division Technical paper DERA/SMC/SM1/TR970039, May 1997 [13] MSS Technical report DERA/MSS1/TR980069/1.0, May 1998 [14] MSS Technical report DERA/MSS/MSMA1/TR990400/1.0, August 1999 [15] MSS Technical report DERA/MSS/MSMA3/CR001238, June 2000 [16] FST Technical report DERA/FST/CET/TR010603, June 2001 [17] FST Technical report QinetiQ/FST/CR023267, May 2002 [18] FST Technical report QinetiQ/FST/CR032630, June 2003 [19] FST Technical report QinetiQ/FST/TR042832, June 2004 [20] FST Technical report QinetiQ/FST/TR050276, June 2005 [21] FST Technical report QinetiQ/FST/TR0601360, June 2006 [22] Technical report QINETIQ/S&DU/T&P/E&M/TR0701148, June 2007 [23] Technical report QINETIQ/08/01656, June 2008 [24] Technical report QINETIQ/09/01120, December 2009 [25] Specification Defence Standard 91-91. Turbine fuel, aviation kerosine type, Jet A-1, NATO code: F-35, JSD: AVTUR. Issued by UK Defence Standardisation, Kentigern House, 65 Brown Street, Glasgow G2 8EX (www.dstan.mod.uk). [26] IP 336: Petroleum products - Determination of sulfur content Energy-dispersive-Xray fluorescence method. https://publishing.energyinst.org. [27] ASTM D7566, Standard specification for aviation turbine fuel containing synthesized hydrocarbons. www.astm.org. [28] BS ISO 4406, Hydraulic fluid power fluids Method for coding the level of contamination by solid particles. 19
ANNEX A RESULTS SUMMARIES A.1 2009 - DATA FROM 608 BATCHES OF JET FUEL REPRESENTING 7 197 709 M 3 Table 3: Minima and maxima for 2009 data and specification limits Def Stan 91-91 Method specification limits Results summary 2009 Min Max Min Max Mean Total acidity, mg KOH/g - 0.015 0 0.015 0.0040 Aromatics, % volume - 25.0 8 5 9 24.0 15.7 Total sulfur, % mass - 0.30 0.001 0.248 0.052 Mercaptan sulfur, % mass - 0.0030 0.0001 0.0027 0.0009 Distillation IBP, C Report 137.6 168.9 150.8 10 % recovery, C - 205.0 161.0 184.3 170.6 50 % recovery, C Report 184.2 210.6 196.4 90 % recovery, C Report 211.0 247.6 235.0 FBP, C - 300.0 236.2 279.6 256.9 Flash point, C 38.0-38.0 51.6 42.0 Density @ 15 C, kg/m 3 775.0 840.0 789.1 817.8 801.9 Freezing point, C - -47.0-69.0 10-47.5-53.1 Viscosity @ -20 C, mm 2 /s - 8.00 3.168 5.822 3.84 Specific energy, Net MJ/kg 42.80-43.02 43.47 43.22 Smoke point, mm 19.0-20.0 27.0 23.21 Naphthalenes, % volume - 3.00 0.17 2.87 1.52 Existent gum, mg/100ml - 7 0 5 1.12 MSEP 85 (70 with SDA) - 71 100 94.4 BOCLE, mm - 0.85 n/a n/a n/a Particulate, mg/l - 1.0 0.00 1.00 0.27 Colour Report 12 30 26.6 Particle count, 4 µm 6 µm 14 µm 21 µm 25 µm 30 µm Report Report Report Report Report Report 12 8 7 7 7 7 22 21 16 13 12 11 16.5 14.3 10.1 8.0 7.4 7.1 8 The limit is 26.5 if using IP 436. All results have been converted to IP 156 equivalent data. 9 The scope of IP 156 is for fuels with aromatics of 5 % and above. A number of batches were reported as <5 %. Therefore, the true minimum is not known. 10 One result of less than <-60 was recorded. Therefore, a lower minimum freezing point than reported in Table 3 is possible. 20
A.2 2010 - DATA FROM 491 BATCHES OF JET FUEL REPRESENTING 6 713 391 M 3 Table 4: Minima and maxima for 2010 data and specification limits Method Def Stan 91-91 specification limits Results summary 2010 Min Max Min Max Mean Total acidity, mg KOH/g - 0.015 0.001 0.015 0.0048 Aromatics, % volume - 25.0 11 5 12 25.0 18.8 Total sulfur, % mass - 0.30 0 0.29 0.047 Mercaptan sulfur, % mass - 0.0030 0.0001 0.0028 0.0009 Distillation IBP, C Report 140.0 164.3 151.1 10 % recovery, C - 205.0 161.2 189.2 171.1 50 % recovery, C Report 185.0 212.3 197.3 90 % recovery, C Report 213.1 246.6 235.6 FBP, C - 300.0 235.4 282.5 257.7 Flash point, C 38.0-38.0 50.9 42.6 Density @ 15 C, kg/m 3 775.0 840.0 792.1 811.5 802.0 Freezing point, C - -47.0-69.8 13-47.6-53.7 Viscosity @ -20 C, mm 2 /s - 8.00 2.365 5.251 3.91 Specific energy, Net MJ/kg 42.80-43.00 43.92 43.19 Smoke point, mm 19.0-19.0 27.0 22.52 Naphthalenes, % volume - 3.00 0.25 2.84 1.53 Existent gum, mg/100ml - 7 0 6 1.10 MSEP 85 (70 with SDA) - 72 100 94.0 BOCLE, mm - 0.85 n/a n/a n/a Particulate, mg/l - 1.0 0.00 1.00 0.26 Colour Report 16 30 27.4 Particle count, 4 µm 6 µm 14 µm 21 µm 25 µm 30 µm Report Report Report Report Report Report 12 7 7 7 7 7 22 21 17 14 13 11 16.2 14.3 10.4 8.7 8.1 7.6 11 The limit is 26.5 if using IP 436. All results have been converted to IP 156 equivalent data. 12 The scope of IP 156 is for fuels with aromatics of 5 % and above. One batch was reported as <5 %. Therefore, the true minimum is not known. 13 One result of less than <-60 was recorded. Therefore, a lower minimum freezing point than reported in Table 4 is possible. 21
A.3 2011 - DATA FROM 765 BATCHES OF JET FUEL REPRESENTING 9 336 574 M 3 Table 5: Minima and maxima for 2011 data and specification limits Method Def Stan 91-91 specification limits Results summary 2011 Min Max Min Max Mean Total acidity, mg KOH/g - 0.015 0.000 0.015 0.0044 Aromatics, % volume - 25.0 14 8.4 24.1 18.6 Total sulfur, % mass - 0.30 0.001 0.210 0.047 Mercaptan sulfur, % mass - 0.0030 0.0001 0.0030 0.0008 Distillation IBP, C Report 140.9 186.4 150.7 10 % recovery, C - 205.0 158.5 195.5 168.9 50 % recovery, C Report 183.6 230.0 194.9 90 % recovery, C Report 210.0 260.0 234.7 FBP, C - 300.0 225.7 296.0 253.9 Flash point, C 38.0-38.0 50.5 42.0 Density @ 15 C, kg/m 3 775.0 840.0 786.9 816.3 801.9 Freezing point, C - -47.0-75.0-47.6-51.9 Viscosity @ -20 C, mm 2 /s - 8.00 2.073 5.243 3.76 Specific energy, Net MJ/kg 42.80-42.83 43.42 43.21 Smoke point, mm 19.0-19.0 28.0 22.89 Naphthalenes, % volume - 3.00 0.14 2.99 1.48 Existent gum, mg/100ml - 7 1 6 1.11 MSEP 85 (70 with SDA) - 54 100 94.8 BOCLE, mm - 0.85 n/a n/a n/a Particulate, mg/l - 1.0 0.00 1.00 0.23 Colour Report 16 30 26.8 Particle count, 4 µm 6 µm 14 µm 21 µm 25 µm 30 µm Report Report Report Report Report Report 12 10 7 7 7 7 22 21 16 16 15 13 15.8 14.1 10.4 8.8 8.0 7.4 14 The limit is 26.5 if using IP 436. All results have been converted to IP 156 equivalent data. 22
A.4 2012 - DATA FROM 1 204 BATCHES OF JET FUEL REPRESENTING 14 104 040 M 3 Table 6: Minima and maxima for 2012 data and specification limits Method Def Stan 91-91 specification limits Results summary 2012 Min Max Min Max Mean Total acidity, mg KOH/g - 0.015 0.001 0.015 0.0038 Aromatics, % volume - 25.0 15 8.2 24.8 17.4 Total sulfur, % mass - 0.30 0.001 0.253 0.055 Mercaptan sulfur, % mass - 0.0030 0.0000 0.0027 0.0008 Distillation IBP, C Report 140.5 163.6 149.4 10 % recovery, C - 205.0 159.5 188.0 168.3 50 % recovery, C Report 178.7 211.3 194.7 90 % recovery, C Report 210.3 256.3 236.2 FBP, C - 300.0 235.9 286.1 260.8 Flash point, C 38.0-38.0 51.5 41.5 Density @ 15 C, kg/m 3 775.0 840.0 784.9 817.1 801.2 Freezing point, C - -47.0-71.6-46.0-54.2 Viscosity @ -20 C, mm 2 /s - 8.00 2.963 4.762 3.75 Specific energy, Net MJ/kg 42.80-43.00 43.51 43.23 Smoke point, mm 19.0-19.0 29.0 23.17 Naphthalenes, % volume - 3.00 0.19 2.87 1.42 Existent gum, mg/100ml - 7 1 6 1.09 MSEP 85 (70 with SDA) - 53 100 94.0 BOCLE, mm - 0.85 n/a n/a n/a Particulate, mg/l - 1.0 0.00 1.00 0.27 Colour Report 12 30 26.6 Particle count, 4 µm 6 µm 14 µm 21 µm 25 µm 30 µm Report Report Report Report Report Report 12 10 7 7 7 7 22 22 19 18 16 15 16.7 14.8 10.9 9.2 8.4 7.6 15 The limit is 26.5 if using IP 436. All results have been converted to IP 156 equivalent data. 23
A.5 2013 - DATA FROM 1 259 BATCHES OF JET FUEL REPRESENTING 14 921 609 M 3 Table 7: Minima and maxima for 2013 data and specification limits Method Def Stan 91-91 specification limits Results summary 2013 Min Max Min Max Mean Total acidity, mg KOH/g - 0.015 0.000 0.015 0.0036 Aromatics, % volume - 25.0 16 8.2 25.0 17.9 Total sulfur, % mass - 0.30 0.0002 0.2000 0.048 Mercaptan sulfur, % mass - 0.0030 0.0001 0.0026 0.0007 Distillation IBP, C Report 134.3 165.7 148.6 10 % recovery, C - 205.0 158.6 180.6 167.7 50 % recovery, C Report 171.1 208.1 193.3 90 % recovery, C Report 193.7 252.2 233.9 FBP, C - 300.0 230.3 284.2 258.0 Flash point, C 38.0-38.0 49.0 41.4 Density @ 15 C, kg/m 3 775.0 840.0 777.5 814.8 799.9 Freezing point, C - -47.0-77.1-46.0-55.0 Viscosity @ -20 C, mm 2 /s - 8.00 2.477 4.767 3.66 Specific energy, Net MJ/kg 42.80-43.00 43.56 43.24 Smoke point, mm 19.0-19.5 29.0 23.34 Naphthalenes, % volume - 3.00 0.04 2.56 1.16 Existent gum, mg/100ml - 7 0 5 1.08 MSEP 85 (70 with SDA) - 65 100 94.5 BOCLE, mm - 0.85 n/a n/a n/a Particulate, mg/l - 1.0 0.00 1.00 0.29 Colour Report 12 30 26.5 Particle count, 4 µm 6 µm 14 µm 21 µm 25 µm 30 µm Report Report Report Report Report Report 12 10 7 7 7 7 22 21 18 16 16 15 16.8 14.8 10.7 9.0 8.3 7.7 16 The limit is 26.5 if using IP 436. All results have been converted to IP 156 equivalent data. 24
ANNEX B FIGURES B.1 TOTAL ACIDITY Total acidity (spec. limit = 0.015 max, mean = 0.0040, st. dev. = 0.004) Total acidity, mg KOH/g Figure 1: Total acidity histogram 2009 Total acidity (spec. limit = 0.015 max, mean = 0.0048, st. dev. = 0.004) Total acidity, mg KOH/g Figure 2: Total acidity histogram 2010 25
Total acidity (spec. limit = 0.015 max, mean = 0.0044, st. dev. = 0.004) Total acidity, mg KOH/g Figure 3: Total acidity histogram 2011 Total acidity (spec. limit = 0.015 max, mean = 0.0038, st. dev. = 0.004) Total acidity, mg KOH/g Figure 4: Total acidity histogram 2012 26
Total acidity (spec. limit = 0.015 max, mean = 0.0036, st. dev. = 0.003) Total acidity, mg KOH/g Figure 5: Total acidity histogram 2013 Trend of the annual mean acidity Total acidity, mg KOH/g Year Figure 6: Total acidity trend graph 27
B.2 AROMATICS Aromatics (spec. limit = 25 max, mean = 15.7, st. dev. = 3.1) Aromatics, % vol Figure 7: Aromatics histogram 2009 Aromatics (spec. limit = 25 max, mean = 18.8, st. dev. = 2.4) Aromatics, % vol Figure 8: Aromatics histogram 2010 28
Aromatics (spec. limit = 25 max, mean = 18.6, st. dev. = 2.1) Aromatics, % vol Figure 9: Aromatics histogram 2011 Aromatics (spec. limit = 25 max, mean = 17.4, st. dev. = 2.0) Aromatics, % vol Figure 10: Aromatics histogram 2012 29
Aromatics (spec. limit = 25 max, mean = 17.9, st. dev. = 2.1) Aromatics, % vol Figure 11: Aromatics histogram 2013 Trend of the annual mean aromatics Aromatics, % volume Year Figure 12: Aromatics trend graph 30
B.3 TOTAL SULFUR Total sulfur (spec. limit = 0.3 max, mean = 0.052, st. dev. = 0.04) Total sulfur, % mass Figure 13: Total sulfur histogram 2009 Total sulfur (spec. limit = 0.3 max, mean = 0.047, st. dev. = 0.04) Total sulfur, % mass Figure 14: Total sulfur histogram 2010 31
Total sulfur (spec. limit = 0.3 max, mean = 0.047, st. dev. = 0.04) Total sulfur, % mass Figure 15: Total sulfur histogram 2011 Total sulfur (spec. limit = 0.3 max, mean = 0.055, st. dev. = 0.05) Total sulfur, % mass Figure 16: Total sulfur histogram 2012 32
Total sulfur (spec. limit = 0.3 max, mean = 0.048, st. dev. = 0.06) Total sulfur, % mass Figure 17: Total sulfur histogram 2013 Trend of the annual mean total sulfur Total sulfur, % mass Year Figure 18: Total sulfur trend graph 33
B.4 MERCAPTAN SULFUR Mercaptan sulfur (spec. limit = 0.003 max, mean = 0.0009, st. dev. = 0.0007) Mercaptan sulfur, % mass Figure 19: Mercaptan sulfur histogram 2009 Mercaptan sulfur (spec. limit = 0.003 max, mean = 0.0009, st. dev. = 0.0006) Mercaptan sulfur, % mass Figure 20: Mercaptan sulfur histogram 2010 34
Mercaptan sulfur (spec. limit = 0.003 max, mean = 0.0008, st. dev. = 0.0005) Mercaptan sulfur, % mass Figure 21: Mercaptan sulfur histogram 2011 Mercaptan sulfur (spec. limit = 0.003 max, mean = 0.0008, st. dev. = 0.0005) Mercaptan sulfur, % mass Figure 22: Mercaptan sulfur histogram 2012 35
Mercaptan sulfur (spec. limit = 0.003 max, mean = 0.0007, st. dev. = 0.0004) Mercaptan sulfur, % mass Figure 23: Mercaptan sulfur histogram 2013 Trend of the annual mean mercaptan sulfur Mercaptan sulfur, % mass Year Figure 24: Mercaptan sulfur trend graph 36
B.5 DISTILLATION IBP Distillation IBP (spec. limit = report, mean = 150.8, st. dev. = 3.6) IBP, C Figure 25: Distillation IBP histogram 2009 Distillation IBP (spec. limit = report, mean = 151.1, st. dev. = 3.6) IBP, C Figure 26: Distillation IBP histogram 2010 37
Distillation IBP (spec. limit = report, mean = 150.7, st. dev. = 4.1) IBP, C Figure 27: Distillation IBP histogram 2011 Distillation IBP (spec. limit = report, mean = 149.4, st. dev. = 3.7) IBP, C Figure 28: Distillation IBP histogram 2012 38
Distillation IBP (spec. limit = report, mean = 148.6, st. dev. = 3.2) IBP, C Figure 29: Distillation IBP histogram 2013 Trend of the annual mean IBP IBP, C Year Figure 30: Distillation IBP trend graph 39
B.6 DISTILLATION 10 % RECOVERY Distillation 10 % recovery (spec. limit = 205 max, mean = 170.6, st. dev. = 3.7) 10 % recovery, C Figure 31: Distillation 10 % recovery histogram 2009 Distillation 10 % recovery (spec. limit = 205 max, mean = 171.1, st. dev. = 5.1) 10 % recovery, C Figure 32: Distillation 10 % recovery histogram 2010 40
Distillation 10 % recovery (spec. limit = 205 max, mean = 168.9, st. dev. = 4.6) 10 % recovery, C Figure 33: Distillation 10 % recovery histogram 2011 Distillation 10 % recovery (spec. limit = 205 max, mean = 168.3, st. dev. = 4.0) 10 % recovery, C Figure 34: Distillation 10 % recovery histogram 2012 41
Distillation 10 % recovery (spec. limit = 205 max, mean = 167.7, st. dev. = 3.5) 10 % recovery, C Figure 35: Distillation 10 % recovery histogram 2013 Trend of the annual mean 10 % recovery 10 % recovery, C Year Figure 36: Distillation 10 % recovery trend graph 42
B.7 DISTILLATION 50 % RECOVERY Distillation 50 % recovery (spec. limit = report, mean = 196.4, st. dev. = 4.4) 50 % recovery, C Figure 37: Distillation 50 % recovery histogram 2009 Distillation 50 % recovery (spec. limit = report, mean = 197.3, st. dev. = 5.2) 50 % recovery, C Figure 38: Distillation 50 % recovery histogram 2010 43
Distillation 50 % recovery (spec. limit = report, mean = 194.9, st. dev. = 5.3) 50 % recovery, C Figure 39: Distillation 50 % recovery histogram 2011 Distillation 50 % recovery (spec. limit = report, mean = 194.7, st. dev. = 5.2) 50 % recovery, C Figure 40: Distillation 50 % recovery histogram 2012 44
Distillation 50 % recovery (spec. limit = report, mean = 193.3, st. dev. = 4.7) 50 % recovery, C Figure 41: Distillation 50 % recovery histogram 2013 Trend of the annual mean 50 % recovery 50 % recovery, C Year Figure 42: Distillation 50 % recovery trend graph 45
B.8 DISTILLATION 90 % RECOVERY Distillation 90 % recovery (spec. limit = report, mean = 235.0, st. dev. = 6.1) 90 % recovery, C Figure 43: Distillation 90 % recovery histogram 2009 Distillation 90 % recovery (spec. limit = report, mean = 235.6, st. dev. = 5.0) 90 % recovery, C Figure 44: Distillation 90 % recovery histogram 2010 46
Distillation 90 % recovery (spec. limit = report, mean = 234.7, st. dev. = 6.2) 90 % recovery, C Figure 45: Distillation 90 % recovery histogram 2011 Distillation 90 % recovery (spec. limit = report, mean = 236.2, st. dev. = 7.9) 90 % recovery, C Figure 46: Distillation 90 % recovery histogram 2012 47
Distillation 90 % recovery (spec. limit = report, mean = 233.9, st. dev. = 7.4) 90 % recovery, C Figure 47: Distillation 90 % recovery histogram 2013 Trend of the annual mean 90 % recovery 90 % recovery, C Year Figure 48: Distillation 90 % recovery trend graph 48
B.9 DISTILLATION FBP Distillation FBP (spec. limit = report, mean = 256.9, st. dev. = 7.2) FBP, C Figure 49: Distillation FBP histogram 2009 Distillation FBP (spec. limit = report, mean = 257.7, st. dev. = 7.5) FBP, C Figure 50: Distillation FBP histogram 2010 49
Distillation FBP (spec. limit = report, mean = 253.9, st. dev. = 12.4) FBP, C Figure 51: Distillation FBP histogram 2011 Distillation FBP (spec. limit = report, mean = 260.8, st. dev. = 9.5) FBP, C Figure 52: Distillation FBP histogram 2012 50
Distillation FBP (spec. limit = report, mean = 258.0, st. dev. = 9.7) FBP, C Figure 53: Distillation FBP histogram 2013 Trend of the annual mean distillation FBP 90 % recovery, C Year Figure 54: Distillation FBP trend graph 51
B.10 FLASH POINT Flash point (spec. limit = 38 min, mean = 42.0, st. dev. = 2.3) Flash point, C Figure 55: Flash point histogram 2009 Flash point (spec. limit = 38 min, mean = 42.6, st. dev. = 2.1) Flash point, C Figure 56: Flash point histogram 2010 52
Flash point (spec. limit = 38 min, mean = 42.0, st. dev. = 2.0) Flash point, C Figure 57: Flash point histogram 2011 Flash point (spec. limit = 38 min, mean = 41.5, st. dev. = 1.9) Flash point, C Figure 58: Flash point histogram 2012 53
Flash point (spec. limit = 38 min, mean = 41.4, st. dev. = 1.7) Flash point, C Figure 59: Flash point histogram 2013 Trend of the annual mean flash point Flash point, C Year Figure 60: Flash point trend graph 54
B.11 DENSITY AT 15 C Density at 15 C (spec. limit = 775 to 840, mean = 801.9, st. dev. = 5.8) Density, kg/m 3 Figure 61: Density histogram 2009 Density at 15 C (spec. limit = 775 to 840, mean = 802.0, st. dev. = 4.0) Density, kg/m 3 Figure 62: Density histogram 2010 55
Density at 15 C (spec. limit = 775 to 840, mean = 801.9, st. dev. = 6.6) Density, kg/m 3 Figure 63: Density histogram 2011 Density at 15 C (spec. limit = 775 to 840, mean = 801.2, st. dev. = 7.0) Density, kg/m 3 Figure 64: Density histogram 2012 56
Density at 15 C (spec. limit = 775 to 840, mean = 799.9, st. dev. = 6.2) Density, kg/m 3 Figure 65: Density histogram 2013 Trend of the annual mean density Density, kg/m 3 Year Figure 66: Density trend graph 57
B.12 FREEZING POINT Freezing point (spec. limit = -47 max, mean = -53.1, st. dev. = 3.6) Freezing point, C Figure 67: Freezing point histogram 2009 Freezing point (spec. limit = -47 max, mean = -53.7, st. dev. = 3.1) Freezing point, C Figure 68: Freezing point histogram 2010 58
Freezing point (spec. limit = -47 max, mean = -51.9, st. dev. = 3.8) Freezing point, C Figure 69: Freezing point histogram 2011 Freezing point (spec. limit = -47 max, mean = -54.2, st. dev. = 4.2) Freezing point, C Figure 70: Freezing point histogram 2012 59
Freezing point (spec. limit = -47 max, mean = -55.0, st. dev. = 3.8) Freezing point, C Figure 71: Freezing point histogram 2013 Trend of the annual mean freezing point Freezing point, C Year Figure 72: Freezing point trend graph 60
B.13 KINEMATIC VISCOSITY AT -20 C Kinematic viscosity (spec. limit = 8 max, mean = 3.66, st. dev. = 0.27) Viscosity, mm 2 /s Figure 73: Kinematic viscosity histogram 2009 Kinematic viscosity (spec. limit = 8 max, mean = 3.91, st. dev. = 0.38) Viscosity, mm 2 /s Figure 74: Kinematic viscosity histogram 2010 61
Kinematic viscosity (spec. limit = 8 max, mean = 3.76, st. dev. = 0.33) Viscosity, mm 2 /s Figure 75: Kinematic viscosity histogram 2011 Kinematic viscosity (spec. limit = 8 max, mean = 3.75, st. dev. = 0.31) Viscosity, mm 2 /s Figure 76: Kinematic viscosity histogram 2012 62
Kinematic viscosity (spec. limit = 8 max, mean = 3.66, st. dev. = 0.27) Viscosity, mm 2 /s Figure 77: Kinematic viscosity histogram 2013 Trend of the annual mean viscosity Viscosity, mm 2 /s Year Figure 78: Kinematic viscosity trend graph 63
B.14 SPECIFIC ENERGY Specific energy (spec. limit = 42.8 min, mean = 43.22, st. dev. = 0.09) Specific energy, MJ/kg Figure 79: Specific energy histogram 2009 Specific energy (spec. limit = 42.8 min, mean = 43.19, st. dev. = 0.09) Specific energy, MJ/kg Figure 80: Specific energy histogram 2010 64
Specific energy (spec. limit = 42.8 min, mean = 43.21, st. dev. = 0.09) Specific energy, MJ/kg Figure 81: Specific energy histogram 2011 Specific energy (spec. limit = 42.8 min, mean = 43.23, st. dev. = 0.09) Specific energy, MJ/kg Figure 82: Specific energy histogram 2012 65
Specific energy (spec. limit = 42.8 min, mean = 43.24, st. dev. = 0.09) Specific energy, MJ/kg Figure 83: Specific energy histogram 2013 Trend of the annual mean specific energy Specific energy, MJ/kg Year Figure 84: Specific energy trend graph 66
B.15 SMOKE POINT Smoke point (spec. limit = 19 min, mean = 23.2, st. dev. = 1.5) Smoke point, mm Figure 85: Smoke point histogram 2009 Smoke point (spec. limit = 19 min, mean = 22.5, st. dev. = 1.5) Smoke point, mm Figure 86: Smoke point histogram 2010 67
Smoke point (spec. limit = 19 min, mean = 22.9, st. dev. = 1.8) Smoke point, mm Figure 87: Smoke point histogram 2011 Smoke point (spec. limit = 19 min, mean = 23.2, st. dev. = 2.0) Smoke point, mm Figure 88: Smoke point histogram 2012 68
Smoke point (spec. limit = 19 min, mean = 23.3, st. dev. = 1.9) Smoke point, mm Figure 89: Smoke point histogram 2013 Trend of the annual mean smoke point Smoke point, mm Year Figure 90: Smoke point trend graph 69
B.16 NAPHTHALENES Naphthalenes (spec. limit = 3 max, mean = 1.52, st. dev. = 0.45) Naphthalenes, %vol Figure 91: Naphthalenes histogram 2009 Naphthalenes (spec. limit = 3 max, mean = 1.53, st. dev. = 1.50) Naphthalenes, %vol Figure 92: Naphthalenes histogram 2010 70
Naphthalenes (spec. limit = 3 max, mean = 1.48, st. dev. = 0.60) Naphthalenes, %vol Figure 93: Naphthalenes histogram 2011 Naphthalenes (spec. limit = 3 max, mean = 1.42, st. dev. = 0.54) Naphthalenes, %vol Figure 94: Naphthalenes histogram 2012 71
Naphthalenes (spec. limit = 3 max, mean = 1.16, st. dev. = 0.50) Naphthalenes, %vol Figure 95: Naphthalenes histogram 2013 Trend of the annual mean naphthalenes Naphthalenes, % vol Year Figure 96: Naphthalenes trend graph 72
B.17 EXISTENT GUM Existent gum (spec. limit = 7 max, mean = 1.1, st. dev. = 0.5) Existent gum, mg/100ml Figure 97: Existent gum histogram 2009 Existent gum (spec. limit = 7 max, mean = 1.1, st. dev. = 0.6) Existent gum, mg/100ml Figure 98: Existent gum histogram 2010 73
Existent gum (spec. limit = 7 max, mean = 1.1, st. dev. = 0.4) Existent gum, mg/100ml Figure 99: Existent gum histogram 2011 Existent gum (spec. limit = 7 max, mean = 1.1, st. dev. = 0.4) Existent gum, mg/100ml Figure 100: Existent gum histogram 2012 74
Existent gum (spec. limit = 7 max, mean = 1.0, st. dev. = 0.3) Existent gum, mg/100ml Figure 101: Existent gum histogram 2013 Trend of the annual mean existent gum Existent gum, mg/100ml Year Figure 102: Existent gum trend graph 75
B.18 MSEP MSEP (spec. limit = 70 min, mean = 94.4, st. dev. = 6.0) MSEP Figure 103: MSEP histogram 2009 MSEP (spec. limit = 70 min, mean = 94.0, st. dev. = 6.4) MSEP Figure 104: MSEP histogram 2010 76
MSEP (spec. limit = 70 min, mean = 92.8, st. dev. = 7.9) MSEP Figure 105: MSEP histogram 2011 MSEP (spec. limit = 70 min, mean = 94.0, st. dev. = 7.7) MSEP Figure 106: MSEP histogram 2012 77
MSEP (spec. limit = 70 min, mean = 94.5, st. dev. = 6.4) MSEP Figure 107: MSEP histogram 2013 Trend of the annual mean MSEP MSEP Year Figure 108: MSEP trend graph 78
B.19 PARTICULATE (GRAVIMETRIC) Particulate (gravimetric) (spec. limit = 1 max, mean = 0.27, st. dev. = 0.2) Particulate, mg/l Figure 109: Particulate histogram 2009 Particulate (gravimetric) (spec. limit = 1 max, mean = 0.26, st. dev. = 0.2) Particulate, mg/l Figure 110: Particulate histogram 2010 79
Particulate (gravimetric) (spec. limit = 1 max, mean = 0.23, st. dev. = 0.2) Particulate, mg/l Figure 111: Particulate histogram 2011 Particulate (gravimetric) (spec. limit = 1 max, mean = 0.27, st. dev. = 0.2) Particulate, mg/l Figure 112: Particulate histogram 2012 80
Particulate (gravimetric) (spec. limit = 1 max, mean = 0.29, st. dev. = 0.2) Particulate, mg/l Figure 113: Particulate histogram 2013 Trend of the annual mean particulate (gravimetric) Particulate, mg/l Year Figure 114: Particulate trend graph 81
B.20 SAYBOLT COLOUR Saybolt colour (spec. limit = report, mean = 26.6, st. dev. = 3.9) Saybolt colour Figure 115: Saybolt colour histogram 2009 Saybolt colour (spec. limit = report, mean = 27.4, st. dev. = 4.0) Saybolt colour Figure 116: Saybolt colour histogram 2010 82
Saybolt colour (spec. limit = report, mean = 26.8, st. dev. = 4.4) Saybolt colour Figure 117: Saybolt colour histogram 2011 Saybolt colour (spec. limit = report, mean = 26.6, st. dev. = 4.0) Saybolt colour Figure 118: Saybolt colour histogram 2012 83
Saybolt colour (spec. limit = report, mean = 26.5, st. dev. = 4.0) Saybolt colour Figure 119: Saybolt colour histogram 2013 Trend of the annual mean saybolt colour Saybolt colour Year Figure 120: Saybolt colour trend graph 84
B.21 PARTICLE COUNTS Particle counts 4 µm (ISO code) (spec. limit = report, mean = 16.5, st. dev. = 1.9) ISO code Figure 121: Particle counts 4 µm ISO code 2009 Particle counts 4 µm (ISO code) (spec. limit = report, mean = 16.2, st. dev. = 1.9) ISO code Figure 122: Particle counts 4 µm ISO code 2010 85
Particle counts 4 µm (ISO code) (spec. limit = report, mean = 15.8, st. dev. = 2.0) ISO code Figure 123: Particle counts 4 µm ISO code 2011 Particle counts 4 µm (ISO code) (spec. limit = report, mean = 16.7, st. dev. = 1.8) ISO code Figure 124: Particle counts 4 µm ISO code 2012 86
Particle counts 4 µm (ISO code) (spec. limit = report, mean = 16.8, st. dev. = 2.0) ISO code Figure 125: Particle counts 4 µm ISO code 2013 Particle counts 6 µm (ISO code) (spec. limit = report, mean = 14.3, st. dev. = 1.9) ISO code Figure 126: Particle counts 6 µm ISO code 2009 87
Particle counts 6 µm (ISO code) (spec. limit = report, mean = 14.3, st. dev. = 2.0) ISO code Figure 127: Particle counts 6 µm ISO code 2010 Particle counts 6 µm (ISO code) (spec. limit = report, mean = 14.1, st. dev. = 2.0) ISO code Figure 128: Particle counts 6 µm ISO code 2011 88
Particle counts 6 µm (ISO code) (spec. limit = report, mean = 14.8, st. dev. = 1.8) ISO code Figure 129: Particle counts 6 µm ISO code 2012 Particle counts 6 µm (ISO code) (spec. limit = report, mean = 14.8, st. dev. = 2.1) ISO code Figure 130: Particle counts 6 µm ISO code 2013 89
Particle counts 14 µm (ISO code) (spec. limit = report, mean = 10.1, st. dev. = 1.6) ISO code Figure 131: Particle counts 14 µm ISO code 2009 Particle counts 14 µm (ISO code) (spec. limit = report, mean = 10.4, st. dev. = 1.8) ISO code Figure 132: Particle counts 14 µm ISO code 2010 90
Particle counts 14 µm (ISO code) (spec. limit = report, mean = 10.4, st. dev. = 1.8) ISO code Figure 133: Particle counts 14 µm ISO code 2011 Particle counts 14 µm (ISO code) (spec. limit = report, mean = 10.9, st. dev. = 1.8) ISO code Figure 134: Particle counts 14 µm ISO code 2012 91
Particle counts 14 µm (ISO code) (spec. limit = report, mean = 10.7, st. dev. = 2.3) ISO code Figure 135: Particle counts 14 µm ISO code 2013 Particle counts 21 µm (ISO code) (spec. limit = report, mean = 8.0, st. dev. = 1.6) ISO code Figure 136: Particle counts 21 µm ISO code 2009 92
Particle counts 21 µm (ISO code) (spec. limit = report, mean = 8.7, st. dev. = 1.8) ISO code Figure 137, Particle counts 21 µm ISO code 2010 Particle counts 21 µm (ISO code) (spec. limit = report, mean = 8.8, st. dev. = 1.7) ISO code Figure 138, Particle counts 21 µm ISO code 2011 93
Particle counts 21 µm (ISO code) (spec. limit = report, mean = 9.2, st. dev. = 1.7) ISO code Figure 139: Particle counts 21 µm ISO code 2012 Particle counts 21 µm (ISO code) (spec. limit = report, mean = 9.0, st. dev. = 2.0) ISO code Figure 140: Particle counts 21 µm ISO code 2013 94
Particle counts 25 µm (ISO code) (spec. limit = report, mean = 7.4, st. dev. = 0.9) ISO code Figure 141: Particle counts 25 µm ISO code 2009 Particle counts 25 µm (ISO code) (spec. limit = report, mean = 8.1, st. dev. = 1.6) ISO code Figure 142: Particle counts 25 µm ISO code 2010 95
Particle counts 25 µm (ISO code) (spec. limit = report, mean = 8.0, st. dev. = 1.3) ISO code Figure 143: Particle counts 25 µm ISO code 2011 Particle counts 25 µm (ISO code) (spec. limit = report, mean = 8.4, st. dev. = 1.4) ISO code Figure 144: Particle counts 25 µm ISO code 2012 96
Particle counts 25 µm (ISO code) (spec. limit = report, mean = 8.3, st. dev. = 1.7) ISO code Figure 145: Particle counts 25 µm ISO code 2013 Particle counts 30 µm (ISO code) (spec. limit = report, mean = 7.1, st. dev. = 0.5) ISO code Figure 146: Particle counts 30 µm ISO code 2009 97
Particle counts 30 µm (ISO code) (spec. limit = report, mean = 7.6, st. dev. = 1.0) ISO code Figure 147: Particle counts 30 µm ISO code 2010 Particle counts 30 µm (ISO code) (spec. limit = report, mean = 7.4, st. dev. = 0.8) ISO code Figure 148: Particle counts 30 µm ISO code 2011 98
Particle counts 30 µm (ISO code) (spec. limit = report, mean = 7.6, st. dev. = 1.0) ISO code Figure 149: Particle counts 30 µm ISO code 2012 Particle counts 30 µm (ISO code) (spec. limit = report, mean = 7.7, st. dev. = 1.3) ISO code Figure 150: Particle counts 30 µm ISO code 2013 99
Trend of the annual mean particle count ISO code Year Figure 151: Particle count trend graph 100
B.22 NEAR SPECIFICATION LIMIT TREND ANALYSIS Near specification limit trend analysis % near specification Year Figure 152: Near specification trend, acidity and aromatics Near specification limit trend analysis % near specification Year Figure 153: Near specification trend, mercaptans, flash point and freezing point 101
Near specification limit trend analysis % near specification Year Figure 154: Near specification trend, smoke point and naphthalenes 102