What is this stuff on my filter, argentina 2009 (nx power lite)


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Some users of biodiesel experience fuel filter failure at temperatures well above the cloud point of the fuel. Much research has been done on oxidative stability of B100. Very little research has been done on Bxx blends of biodiesel and petroleum diesel. This paper examines why biodiesel must always be treated with anti-oxidant not matter what the Racimat Induction Period of the base B100 fuel.

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What is this stuff on my filter, argentina 2009 (nx power lite)

  1. 1. Phil Bureman Nalco Company Industry Technical Consultant – BioFuels [email_address] What Is This Stuff on my Fuel Filter? 13 th Latin American Congress on Fats & Oils Rosario, Argentina, November 1, 2009 Tim McGinnis Nalco Company Research Scientist - Research Analytical [email_address] Kim Peyton Nalco Energy Services Research Scientist [email_address]
  2. 2. Who Is Nalco? <ul><li>Nalco is a global company with approximately $4 billion in annual sales </li></ul><ul><li>Nalco has 2 Major Divisions </li></ul><ul><li>Nalco Water & Process Solutions </li></ul><ul><ul><li>works with BioFuel producers including biodiesel </li></ul></ul><ul><li>Nalco Energy Services </li></ul><ul><ul><li>works with petroleum refiners and fuel marketers </li></ul></ul><ul><li>There is regular information sharing between the two divisions </li></ul>
  3. 3. The Future of Biodiesel <ul><li>Biodiesel fuel quality continues to improve </li></ul><ul><li>Conversion technologies are becoming more efficient </li></ul><ul><li>New feed stocks are available </li></ul><ul><ul><li>Advanced feed stocks are being developed </li></ul></ul><ul><li>Governments are becoming supportive of biofuels </li></ul><ul><ul><li>Some more than others </li></ul></ul><ul><li>Cold weather issues are becoming better understood and managed </li></ul><ul><li>We have one major obstacle between our industry and success: </li></ul>
  4. 4. The Future of Biodiesel <ul><li>Biodiesel producers must better understand petro diesel </li></ul><ul><li>Petro diesel refiners must better understand biodiesel </li></ul><ul><li>If the Biodiesel Producer and the Petroleum Refiner regularly communicate and work together to solve performance problems, then both will be profitable and the Biodiesel user will be a Satisfied Customer! </li></ul>
  5. 5. Background <ul><li>There has been much study of B100 oxidation stability </li></ul><ul><ul><li>Test methods such as Rancimat are well established, repeatable, and quite useful. </li></ul></ul><ul><li>There has been some study of B100 oxidation stability: </li></ul><ul><ul><li>Under long term storage conditions </li></ul></ul><ul><ul><li>Under stressful conditions of heat & humidity </li></ul></ul>Storage Condition @ 30 C in saturated humidity Beef Tallow B100 with no oxidation inhibitor Date Week Rancimat Induction Period (Hours) % Reduction in Oxidation Stability 9/29/2008 0 3.45 - 10/6/2008 1 1.1 68.1% 10/20/2008 3 0.8 76.8% 11/3/2008 5 0.6 82.6% 11/17/2008 7 0.4 88.4%
  6. 6. Background <ul><li>There has been very little study of the oxidation stability of Bxx blends </li></ul><ul><ul><li>Especially with the new petroleum based Ultra Low Sulfur Diesel (ULSD) fuels </li></ul></ul><ul><li>Why is this important? </li></ul>
  7. 7. Background <ul><li>There is a significant amount of Bxx stored for long periods of time: </li></ul><ul><ul><li>Farms (typical 3 month storage) </li></ul></ul><ul><ul><li>Home heating oil (1 year storage) </li></ul></ul><ul><ul><li>Construction contractors (3 months) </li></ul></ul><ul><ul><li>Back-up fuel power generators </li></ul></ul><ul><ul><ul><li>Hospitals </li></ul></ul></ul><ul><ul><ul><li>Electric power utilities (1-5 years) </li></ul></ul></ul><ul><li>There have been credible reports of excessive fuel filter fouling in B5, B10 & B20 </li></ul><ul><ul><li>In some Bxx storage tanks </li></ul></ul><ul><ul><li>At some “fuel blender” terminals </li></ul></ul><ul><ul><ul><li>During warm weather </li></ul></ul></ul><ul><ul><ul><li>No sediment was found on the B100 filter </li></ul></ul></ul>Nalco decided to investigate <ul><ul><li>The weather was warm </li></ul></ul>
  8. 8. Background <ul><ul><li>The filter foulant was not biological </li></ul></ul><ul><ul><li>The filter foulant was not: </li></ul></ul><ul><ul><ul><li>Petroleum fuel varnish </li></ul></ul></ul><ul><ul><ul><li>Rust or </li></ul></ul></ul><ul><ul><ul><li>A known petroleum tank sludge or sediment </li></ul></ul></ul><ul><ul><li>The filter foulant did not contain unusual amounts of water, alkali metals, soap, glycerin or glycerides </li></ul></ul><ul><ul><li>Since the problem occurred in Bxx and not B100, Nalco decided to investigate long term Bxx storage stability </li></ul></ul>
  9. 9. Background <ul><li>ASTM D4625 was chosen as the fuel ageing method </li></ul><ul><ul><li>Long history of use to simulate 1 year of storage for petroleum fuels </li></ul></ul><ul><ul><li>Runs for 13 weeks at 110 o F (43 o C), with no agitation </li></ul></ul><ul><li>Three different types of B100 were chosen, Biodiesel made from </li></ul><ul><ul><li>Soy Oil (5.1 hour Rancimat as a B100) </li></ul></ul><ul><ul><li>Mixed source (0.6 Hour Rancimat as a B100) </li></ul></ul><ul><ul><li>Palm oil feedstock (4.8 Hour Rancimat as a B100) </li></ul></ul><ul><ul><li>None of the B100’s had been treated with anti-oxidant </li></ul></ul><ul><ul><li>Some of the B20 and B5 samples were treated with anti-oxidants </li></ul></ul><ul><ul><li>The ULSD had not been treated with stabilizer or lubricity aid </li></ul></ul><ul><li>ULSD (Ultra Low Sulfur Petro Diesel), B100, B20 and B5 blends were tested </li></ul>
  10. 10. After ASTM D4625, 110 o F (43 o C) , 13 weeks With No Antioxidant Treatment There was no indication of significant sediment formation ULSD Mixed Soy Palm Rancimat Hours Prior to ASTM D4625: >8.0 Hrs 0.6 Hrs 5.1 Hrs 4.8 Hrs
  11. 11. A thick, gelatinous sediment layer formed at the bottom of the B20 blend to which no antioxidant has been added. This sediment did not form in inhibited B-20. Untreated Anti-Ox #1 @ 100 ppm in the B100 Anti-Ox #2 @ 100 ppm in the B100 ~ 10.5 vol% A smaller amount of the same sediment formed in the B5 Non-Inhibited SOY B20 (Rancimat before testing >8.0 Hrs), in ULSD without anti-oxidant treatment is unstable after accelerated stability testing
  12. 12. A thick, gelatinous sediment layer formed at the bottom of the B20 blend to which no antioxidant has been added. This sediment did not form in inhibited B-20. Untreated Anti-Ox #1 @ 100 ppm in the B100 Anti-Ox #2 @ 100 ppm in the B100 ~ 7.0vol% A smaller amount of the same sediment formed in the B5 Non-Inhibited Mixed Source B20 (Rancimat @ start 3.7 Hrs), in ULSD showed similar instability when subjected to ASTM D4625
  13. 13. Observations <ul><li>The sediment layer did form in the B20 and B5 blends made from soy oil and mixed source feed stocks </li></ul><ul><ul><li>The soy oil B20 had a relatively high Rancimat stability of 5.1 hours </li></ul></ul><ul><ul><li>The mix source B20 had a very low Rancimat stability of 0.6 hours </li></ul></ul><ul><ul><li>The sediment layer did not form in the palm oil B20 or B5 blends </li></ul></ul><ul><li>Low level, anti-oxidant treatment prevented the formation of the sediment layer in all of the B20 & B5 blends </li></ul><ul><li>The sediment layer did not form in any of the B100 fuels or the petroleum based ULSD </li></ul>
  14. 14. Three Big Questions <ul><li>What is the sediment layer? </li></ul><ul><li>How did the sediment layer form? </li></ul><ul><li>If the biodiesel was oxidizing, why did the sediment layer not form in any of B100 samples that were subjected to the same ageing stress? </li></ul><ul><ul><li>Is the petro diesel involved? </li></ul></ul><ul><ul><ul><li>If so, how? </li></ul></ul></ul><ul><li>Please allow me to introduce you to Dr Tim McGinnis who will help us answer these questions………… </li></ul>
  15. 15. Gas Chromatography with Mass Spectrometry (GCMS) was used to determine the identity many of the compounds in the separated layer Thermo Electron Trace DSQ GCMS was operated in two distinct ionization modes to give the utmost information regarding the identities of degradation products of FAME Electron Impact Ionization - Gives a “fingerprint” that can be searched against standard spectral databases Methane Chemical Ionization - Gives less fragmented ion patterns which are directly related to the components’ molecular weights Also used were Purge and Trap techniques to look at low molecular weight volatiles, and Gas Chromatography with Flame Ionization Detection GCFID to examine higher molecular weight species.
  16. 16. Initial GCMS Total Ion Chromatogram of Sediment Showing Peaks from Eluting Compounds <ul><li>The composition of the sediment is very complex, with lots of overlap of chemical species. </li></ul><ul><li>Petro diesel compounds are included, </li></ul><ul><ul><li>but make up only a fraction of the total . </li></ul></ul><ul><li>The remaining compounds with the highest concentration were found to be various polar oxygenates. </li></ul>|------ Molecular Weights<500 ----|
  17. 17. High Temperature GCFID Chromatogram of Sediment High capacity, thin filmed column, along with on-column injection, allows for loading and elution of higher MW species |--------------------------------------------------------| Broadly Eluting Compounds with Molecular Weights Ranging from ~ 500 to 1000 (or greater) “ SIM DIST” Column
  18. 18. GC Profile of Sediment vs. Analytical Standards Analyzed Under Identical Conditions (MAG) (DAG) (TAG) Comparing the sediment against standards reveals that the high MW species in the sediment are at least as large as these known high MW contaminants encountered in biofuel. Detailed analyses suggest, though, that these high MW compounds are not merely MAG, DAG, TAG, etc., and are likely more complex reaction products.
  19. 19. The Sediment Layer is Very Complex ! We want to identify as many chemical species as possible, but how? - There is a great deal of coelution of multiple components, meaning that some “peaks” contain several species. - The mass spectral “fingerprints” obtained from examining these peaks are often combinations, and therefore do not always provide useful information. A Useful Approach . . . . . - We can separate the sediment into fractions based on solubility in solvents with different degrees of polarity. - We can then analyze each fraction separately to obtain more detailed information about the components present.
  20. 20. Solid Phase Extraction (SPE) First, sediment is injected, or “loaded” into a silica containing SPE cartridge Non-polar Cyclohexane is passed through Cyclohexane solubles collected and analyzed Next, slightly polar Cyclohexane:MTBE mix is passed through Cyclohexane:MTBE s olubles are collected and analyzed Next, moderately polar MTBE is passed through MTBE solubles are collected and analyzed Finally, polar Methanol is passed through Methanol solubles are collected and analyzed Note: MTBE is Methyl-t-Butyl Ether
  21. 21. Gas Chromatographic Profile of Non-Polar Fraction from Solid Phase Extraction Primary Biodiesel Components The bulk of the components are broad spectrum diesel fuel.
  22. 22. Gas Chromatographic Profile of Slightly Polar Fraction from Solid Phase Extraction There are no diesel fuel components in this fraction. All of the peaks seen are polar substances which are not soluble in cyclohexane alone. |------------------------| Mostly degradation products from the oxidation of biodiesel
  23. 23. Gas Chromatographic Profile of Moderately Polar Fraction From Solid Phase Extraction Thought to be oxidized biodiesel without cleavage |---------------------------------------| Higher MW Species
  24. 24. Gas Chromatographic Profile of Highly Polar Fraction from Solid Phase Extraction There are significant amounts of high molecular weight species that are soluble primarily in the more polar solvents. These are not MAG, DAG, TAG, etc. They appear to be addition products (oligomers) of some of the oxidation products, which must have substantial amounts of polar functionality in their molecular structure. |--------------------------------|
  25. 25. Organic Acids Detected in the B20 sediment
  26. 26. More examples of some species detected in the B20 sediment
  27. 27. Reaction Byproducts and Natural Components Detected in the B20 sediment How were these compounds formed?
  28. 28. The High Degree of Un-saturation in some FAME BioFuels, make them Particularly Susceptible to Oxidative Degradation Note that Tallow & Rape based biodiesel contains > 50% unsaturated compounds. Oxidative degradation of animal based biodiesel can and does occur. This is an important fact that is often overlooked! FAME Compound by GC/MS FAME Type, Area % Soy-D Soy-W Mixed Veg. Tallow Palm RME 16:0 Methylpalmate 8.9 11.5 15.3 23.5 44.7 9.9 16:1 Methylpalmitoleate - - - 1.6 - - 18:1 Methyloleate 38.1 34.7 34.2 43.8 37.5 59.2 18:2 Methylinoleate 43.6 47.9 22.9 12.8 5.3 26.2 18:0 Methylstearate 6.2 5.3 10.0 13.6 11.7 3.3 Other Unsaturated Compounds 3.2 0.6 17.6 4.7 0.8 1.4
  29. 29. Biodiesel (FAME) Instability In Biodiesel Blends <ul><li>Degradation of biodiesel components can be caused by: </li></ul><ul><ul><li>Attack of oxygen at sites where unsaturation (double bonds) are present, resulting in cleavage of the molecule </li></ul></ul><ul><ul><li>Hydrolysis of the ester groups due to attack by water </li></ul></ul><ul><ul><li>Both unsaturated & saturated compounds are at risk </li></ul></ul>O 2 H 2 O
  30. 30. Oxygen Attack at Point of Unsaturation
  31. 31. Secondary Oxygen Attack of the Reaction Product
  32. 32. Hydrolysis of Esters to Produce Acids
  33. 33. Big Q #1: What Is In This Sediment Layer? <ul><li>Products of primary & secondary oxidation </li></ul><ul><li>Products of hydrolysis </li></ul><ul><li>Complex higher molecular weight compounds </li></ul><ul><ul><li>May include oligomeric compounds formed from oxidized FAME </li></ul></ul><ul><li>Also included are other materials such as: </li></ul><ul><ul><li>Water, </li></ul></ul><ul><ul><li>Natural impurities, </li></ul></ul><ul><ul><li>Process impurities. </li></ul></ul>
  34. 34. Big Q #2: How Is This Layer Formed? <ul><li>Sediment Layer Formation is believed to occur when the polar oxidation and hydrolysis products come together and begin to form aggregates in the less-polar petroleum based ULSD Fuel </li></ul><ul><li>These aggregates can be envisioned as micro-emulsions </li></ul><ul><ul><li>They are dispersed within the liquid. </li></ul></ul><ul><ul><li>They become unstable entities in solution due to their size, polarity, etc. </li></ul></ul><ul><ul><li>They begin to coalesce and form a separate liquid phase which is not soluble in the Bxx. </li></ul></ul><ul><li>There is still a strong organic character to the new layer, which results in the partition inclusion of some diesel fuel and biodiesel. </li></ul>
  35. 35. <ul><li>Further analysis revealed that many of the same aggregates were found to be present in the aged B100 samples </li></ul><ul><ul><li>The sediment layer did not form since the bulk B100 solution retained most of its original polarity </li></ul></ul><ul><ul><li>The same sediment layer can be expected to form when these aged B100’s sample are blended with petro based ULSD </li></ul></ul><ul><ul><li>Other system stress on oxidation product solubility - such as cold temperature, could be expected to produce a sediment layer in a Bxx blend made with non-polar fuels such as ULSD </li></ul></ul><ul><ul><ul><li>This possibility needs further study </li></ul></ul></ul><ul><ul><li>We plan to investigate if oxidation in raw oil feedstock can also produce these sediments </li></ul></ul>Big Q #3: Why did the sediment layer not form in the B100? Please allow me to ask Phil to return now for our summary
  36. 36. Summary <ul><li>Biodiesel producers cannot expect all of their fuel to be consumed quickly </li></ul><ul><ul><li>A biodiesel producer’s long term success is tied to the trouble free use of stored B100 or Bxx </li></ul></ul><ul><ul><li>Biodiesel stored as B100 or as Bxx will oxidize </li></ul></ul><ul><li>De-sulphurization of petro diesel increases the chance that biodiesel oxidation products will form sediment layers in Bxx and result in filter plugging issues </li></ul>
  37. 37. <ul><ul><li>Rancimat stability is not necessarily a good predictor for the formation of oxidation sediment layers in Bxx blends </li></ul></ul><ul><ul><li>B20 & B5, made with a 5.1 hour Rancimat B100 generated a sediment layer </li></ul></ul><ul><ul><li>B20 & B5, made with a 0.6 hour Rancimat B100 generated the same sediment layer </li></ul></ul><ul><ul><li>B20 & B5, made with a 4.8 hour Rancimat B100 generated no sediment layer </li></ul></ul><ul><ul><li>All of the B20 and B5 blends that were treated with a small amount of inexpensive anti-oxidant generated no sediment layer </li></ul></ul>Summary
  38. 38. <ul><li>Any B100, regardless of the measured Rancimat stability, has the potential to form this sediment layer </li></ul><ul><ul><li>This phenomenon may not be easily measurable in B100 </li></ul></ul><ul><ul><li>This phenomenon may not be observable until the fuel is blended with petro diesel </li></ul></ul><ul><ul><li>When biodiesel oxidizes, real potential exists for fuel filter fouling and plugging </li></ul></ul><ul><ul><li>Other issues may also result from oxidation such as: </li></ul></ul><ul><ul><ul><li>Injector fouling </li></ul></ul></ul><ul><ul><ul><li>Fouling of the Diesel Particulate Filter (DPF) </li></ul></ul></ul><ul><ul><ul><li>Shortened lubricating oil life </li></ul></ul></ul>Summary
  39. 39. <ul><li>To paraphrase a famous quote about Las Vegas, Nevada – the famous gambling city in the USA: </li></ul><ul><li>What happens in petro diesel, stays in the petro diesel </li></ul><ul><li>What happens in biodiesel, stays in biodiesel </li></ul><ul><li>What happens in blends of biodiesel with petro diesel, can affect both the petro diesel refiner and the biodiesel producer because it can affect your common customer! </li></ul>Summary
  40. 40. A fully detailed report of this work is expected to be published this year in the Journal of ASTM International – Special Issue on BioFuels Thank you for your time! Questions?