Today s Fuels and Compatibility With Storage Systems

Transcription

1 Today s Fuels and Compatibility With Storage Systems NISTM Alexandria, VA June 9, 2015 LO R R I G R A I N AW I D I R E C TO R O F T E C H N I C A L S E R V I C E S S T I / S P FA LG R A I N AW S T E E LTA N K. C O M

2 Three Fuels of Concern Today Ultra Low Sulfur Diesel (ULSD) Biodiesel Ethanol Blends 2

3 RESEARCH: Biofuels FRP tank blistering and flaking STEEL TANK INSTITUTE/STEEL PLATE FABRICATORS ASSOCIATION

4 4

5 Ethanol Studies Intermediate Ethanol Blends Infrastructure Materials Compatibility Study, M. Kass, ORNL TM-2010/326, Preliminary Compatibility Assessment of Metallic Dispenser Materials for Service in Ethanol Fuel Blends, ORNL/TM- 2009/286. Elastomer Compatibility to a Gasoline Standard Containing Intermediate Levels of Ethanol, M Kass et al., 21st International Fluid Sealing Conference, Dispensing Equipment Testing with Mid-Level Ethanol/Gasoline Test Fluid, Document No , NREL/SR- 7A Boyce and Chapin, 2010.

6 Ethanol Studies Analysis of Underground Storage Tank System Materials to Increased Leak Potential Associated with E15 Fuel, EPA report Compatibility Assessment of Metallic Dispenser Materials for Service in Ethanol Fuel Blends up to E85, ORNL Technical Memorandum Analysis of Steel Underground Storage Tank failure storing Ethanol, 2013 Compilation of failure reports, ASTWMO, 2013

7 2013 study: DW FRP tank, 23 years UST fibers exposed due to chemical exposure.

8 2013 study: 23-year old FRP tank storing E10 The tanks were so brittle that they split in two when lifting lugs were used.

9 DNV Study Steel & Ethanol - Compatible Exposure time, 2 months at ambient temperature. 95% Fuel grade ethanol (FGE) - nitrogen purge: corrosion rate: to 0.02 mm/y 90%gasoline-10% FGE, nitrogen purge: mm/year Corrosion below detection limit 70% gasoline-30%fge, air purge 90% gasoline-10% FGE, air purge 95% FGE, air purge

10 ORNL Ethanol Study All materials which could be in UST system were tested Metals negligible corrosion Elastomers (gaskets, seals, etc.) some not compatible with E15. Found that increased swelling caused important property loss. Plastics included older and newer FRP resins Resins exhibited between 7% - 25% swell Volume swell corresponds to material softening

11 2012 study Evaluated four resin types representative of those used in legacy and modern FRP UST construction: The pre-1990 resin was severely damaged from exposure to CE25a, along with one of the post-1990 resins. The addition of glass to the test samples may prevent swelling.

12 ORNL Ethanol Study, cont. Residual fuel in the polymer is likely responsible for the material softening. Even after drying at 60 C for 65 hours, some level of fuel was retained within the plastics. The highest property changes observed were for nylon 11, nylon 12, PETG, PP, and vinyl and polyester resins Volume and softening of PVDF, acetals, nylons, PBT, PETG, and thermoset resins increased to varying degrees with exposure to ethanol. mild steel and stainless steel were found to be essentially immune to corrosion

13 The study showed negligible corrosion of either steel or aluminum immersed in either CE10a or CE17a. (Aggressive blend of 10% and 17% ethanol.) 2012 study

14 2010 study Testing with mid-level ethanol/gasoline: In this study, there was no noted effect on metallic parts of equipment.

15 Corrosion in Sumps

16 Steel Tank Interior E85

17 Exterior Mold on Ethanol Tanks

18 Close-Up Area

19 Other Research Biodiesel and Steel Compatibility Study, 2007, SwRI Biodiesel Handling Use Guide, NREL DNV Material Compatibility in Biofuels, Gui, Beavers, James & Sridhar, 2011 Corrosion Behavior of Carbon Steel Coupons and Injection System Components in Soybean Methyl Biodiesel, Cavalcanti & Mansur

20 Biodiesel STI conducted a study with NBB in 2007 Steel found to be compatible with various types of biodiesel Soy Animal fat B5 thru B100 Both ULSD and 3500 ppm diesel fuel used 20

21 Steel Samples

22 Visual Inspection Upon visual inspection of the test coupons, a small amount of surface rusting was observed Figure 4. Photographs of carbon steel specimens exposed to ULSD and soy-based biodiesel blends with and without the presence of water: (a) 100 % biodiesel, no w added; (b) 50 % biodiesel + 50 %ULSD, no water added; (c) 100 % petrodiesel, no water added; (d) 100 % biodiesel, 1 vol% water added; (e) 50% biodiesel + 50 % ULSD, 1 vol% water added and (f) 100 % ULSD, 1 vol% water added. Exposure time: 2 months.

23 Surface Rust In most cases, the amount of surface rusting was slightly higher in 100 % ULSD than in biodiesel or biodiesel + ULSD blends. This surface rusting was caused by a reaction between the surface oxide layer of the metal and the fuel blend.

24 Low magnification optical micrographs 100% Biodiesel 50% ULSD/ 50% Biodiesel 100% ULSD No water added to any fuel

25 Typical Microscope Images toolmark 1 mm 100 % animal-based biodiesel, no water added

26 Sample 25 Greatest weight loss occurred with 5% animal based biodiesel/ ULSD/ 1% water Optical examination indicated no measurable pits on this sample Corrosion rate calculated at 0.09 mm/yr Equates to Excellent Corrosion Resistance rating

27 27 Ultra Low Sulfur Diesel Issues Corrosion of metal components within tanks storing ULSD

28 Corrosion Occurring in Vapor, Product and Tank Bottoms

29 Oct 2013

30 STP column pipe inside FRP tank

31 Upper section of STP vapor only

32 Pump connection corroded thru

33 In service less than one year STP Column Pipe

34 Had to be pried out Check Valve

35 STI conducted own study Study included both fiberglass and steel tanks USTs from five regions of the countries tested One fiberglass and one steel tank in each region Tanks were chosen randomly with no previous investigation of any corrosion issues Both fuel and water bottom sample obtained 35

36 36 STI Research Las Vegas service stations tanks under same owner FRP tank vapor control fitting top right photo Steel tank vapor control fitting bottom right photo

37 Results Ethanol found in all but one region of the country How is ethanol getting in diesel fuel Transporting trucks is one possibility Also possible for ethanol to be formed inside the tank Acetic acid found in all but one region of the country 37

38 Steel Tank Top Vapor Space is Clean

39 Best Management Practice Improve Storage Tank Maintenance

40 Inspection & Maintenance STI R111 Storage Tank Maintenance Check Your Fuel - ASTM