Document ID: EPA-HQ-OAR-2011-0894-0003
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2012-01-20T05:00Z

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NACE Testing of MFA-10 additive

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NACE Testing of MFA-10 additive

Executive Summary: 

The formula for MFA-10 has been modified, which impacts the Octamix waiver associated with this product. A modification to this waiver is being pursued. Part of this process is to provide the EPA with corrosion testing to demonstrate product efficacy. As such, corrosion testing was conducted on the original and modified MFA-10. (The modified version is being called TOLAD(TM) MFA-10A.) The testing was based upon prescribed conditions set forth in a document detailing the waiver and treat rate approved in this waiver.
According to the waver, the following conditions must be met:

   The final fuel consists of a maximum of five percent by volume methanol, a minimum of 2.5 percent by volume co-solvent in unleaded gasoline. The co-solvents are any one or a mixture of ethanol, propanols, butanols, pentanols, hexanols, heptanols and octanols, within the following constraints: the ethanol, propanols and butanols or mixtures thereof must compose a minimum of 60 percent by weight of the co-solvent mix, whereas a maximum limit of 40 percent by weight of the co-solvent mix is placed on the pentanols, hexanols, heptanols and octanols or mixtures thereof. Furthermore, the heptanols and octanols are limited to a maximum five percent by weight of the higher molecular weight alcohol mix (pentanols, hexanols, heptanols and octanols).

Based on this guidance, an "octamix" blend was prepared in the lab consisting of 92.5% regular unleaded gasoline, 5% methanol and 2.5% denatured fuel grade ethanol. This mixture did not prove to be significantly corrosive, so testing was also conducted on the gasoline alone, as well as a mixture of gasoline and fuel ethanol. Also, due to the lack of corrosivity of the "octamix" blend, some common corrosive agents were added to facilitate product comparison and testing.

Based on the testing conducted, the two formulations TOLAD(TM) MFA-10 and TOLAD(TM) MFA-10A are equivalent in performance. See Tables 1 & 2 for test results.

Test Method: 
NACE Standard TM-01-72: Anti-Rust Properties of Cargoes in Petroleum Product Pipelines Three hundred milliliters of the test sample was measured into a chemically clean and dry beaker. After preparation by polishing, the steel test specimen was immersed in the test fuel solution, together with thermometer and stirrer, and placed into the water bath previously heated to 38 +- 1°C (100 +- 2°F). After stirring for 30 minutes, 30 ml of distilled water was added.  Stirring of the sample continued for an additional 3.5 hours before the final inspection was made with a lighted glass of 2x magnification. The test spindles were rated according to the scale in Table 2.

Table 1 NACE TM-01-72 Corrosion Test Results

                                    Product
                                  Treat Rate
                            Rating ("Octamix")
                         Rating (gasoline + 2.5% EtOH)
                            Rating (gasoline only)
                                     None
                                       0
                                      B++
                                       C
                                       D
                                TOLAD(TM) MFA-10
                                   42.7 mg/L
                                       A
                                       A
                                       A
                               TOLAD(TM) MFA-10A
                                   42.7 mg/L
                                       A
                                       A
                                       A

Table 2 NACE TM-01-72 Corrosion Test Results

                                    Product
                                  Treat Rate
                            Rating ("Octamix")*
                           Rating ("Octamix")**
                                     None
                                       0
                                       C
                                       D
                                TOLAD(TM) MFA-10
                                   42.7 mg/L
                                      B+
                                       B
                               TOLAD(TM) MFA-10A
                                   42.7 mg/L
                                      B+
                                       B
* Increased corrosivity due to addition of formic & acetic acids
** Increased corrosivity due to addition of formic & acetic acids and sodium chloride

Table 3 NACE TM-01-72 Test Rating Scale

                                    Rating
                       Percentage of Test Surface Rusted
                                       A
                                     None
                                      B++
          Less that 0.1% (2 or 3 spots of no more than 1 mm diameter)
                                      B+
                                 Less than 4%
                                       B
                                   5 to 25%
                                       C
                                   25 to 50%
                                       D
                                   50 to 75%
                                       E
                                  75 to 100%

Conclusions/Recommendations:
TOLAD(TM) MFA-10 and TOLAD(TM) MFA-10A, were shown to be equivalent in performance. As such, the TOLAD(TM) MFA-10A formula should be acceptable for submission to the EPA for modification of the existing waiver.

Figure 1 Photo of Test Spindle in Untreated Fuel ("Octamix") vs. "Octamix" Treated with TOLADTM MFA-10 and TOLAD(TM) MFA-10A

Treated  with TOLAD(TM) MFA-10
                         Treated  with TOLAD(TM) MFA-10
                         Treated with TOLAD(TM) MFA-10A
                         Treated with TOLAD(TM) MFA-10A
                                   Untreated
                                   Untreated
 
Table 4 Physical Properties of TOLAD(TM) MFA-10A
                           Viscosity @ 100ºF (cSt)
                                     17.5
                            Viscosity @ 32ºF (cSt)
                                     92.7
                            Viscosity @ 0ºF (cSt)
                                     294.2
                            Specific Gravity, 60ºF
                                    0.9144
                               Ash Content (wt%)
                                     0.02
                            Flash Point, PMCC (ºF)
                                      98
                                  Appearance
                           Clear, dark amber liquid
                             Treat Level (minimum)
                                    25 ppm
                             Treat Level (average)
                                    50 ppm
                             Treat Level (maximum)
                                    300 ppm