Statement to Subcommittee E to accompany the proposed change to D975 to include a specification for ultra-low sulfur diesel fuel.
The proposed change to D975 includes in the diesel specification standard two new ultra-low sulfur grades. This statement provides you with some background on technical and other issues considered by the ULSD Task Force.
The approach taken by the TF for this proposal appears to be the same as the approach taken when Low Sulfur grades were added to D975; that is, we changed the sulfur requirement and left everything else the same. The TF is considering other properties that may be relevant to ULSD, but we are not including them in this proposal. The sulfur level is not in question, so we expect this proposal to be much less controversial than other changes that may be proposed. This part of the expected changes to D975 may go through ASTM with relative ease. The TF fully expects to address other performance properties in the coming months. We expect to use this column in D975 to propose other changes as we discuss them and reach agreement on a proposal for ballot.
We are aware that lubricity and several other changes to D975 are under consideration, in some cases being at Committee D2 ballot in 2H03. The version of D975 used as the basis for this proposal is the latest version provided by ASTM. Before D2 ballot we will incorporate other changes in D975 that have been approved while this work has progressed.
All No. 1-D and No. 2-D grades have a designation that gives the maximum sulfur content allowed by the specification.
Proposed designation Current designation
No. 1-D S15 ----
No. 1-D S500 Low Sulfur No. 1-D
No. 1-D S5000 No. 1-D
No. 2-D S15 ----
No. 2-D S500 Low Sulfur No. 2-D
No. 2-D S5000 No. 2-D
The new designations were picked because of the difficulty of reaching agreement on exactly what ULSD means. Using S(sulfur content) is objective and gives information.
The Task Force discussed ordering in the designation. The majority of the TF favors the order shown above because it emphasizes the bulk of the performance characteristics of the fuel, but some members favor the following alternative order.
S15 No. 1-D S15 No. 2-D
S500 No. 1-D S500 No. 2-D
S5000 No. 1-D S5000 No. 2-D
Proponents of this order think that the order proposed in the ballot will make it easier to confuse the S500 and S5000 grades. The alternative order is also in keeping with the current specification, which puts Low Sulfur before the grade.
Question for Sub E members: Which order do you prefer? If you prefer the alternative order please indicate this in the comments section of your ballot.
There is also some concern that S500 and S5000 will be confused because of the similarity in their appearance. Two suggestions have been made to minimize confusion and their various combinations are shown below.
A (Current ballot) B C D
S15 S15 S 15 S 15
S500 S500 S 500 S 500
S5000 S5,000 S 5000 S 5,000
Any of these can be used either before or after the No. 1-D and No. 2-D part of the designation, so the question of which to use is independent of the question above.
Question for Sub E members: Which order do you prefer? If you prefer B, C or D please indicate this in the comments section of your ballot.
Two test methods for sulfur have been added to the current version, D5453 and D6920. All three methods proposed for the S15 grades were examined in the recent round robin of sulfur methods. With thanks to Kishore Nadkarni, Chair of Sub 3, I am able to share with you some results of that study. The report is still going through ASTM approval process, so please treat this information appropriately.
Methods used for diesel fuel:
Designation Name Range
D3120-96 Trace Quantities of Sulfur in Light Liquid Petroleum Hydrocarbons by Oxidative Microcoulometry 3 to 100 ppm
D5453-00 Total Sulfur in Light Hydrocarbons, Motor Fuels, and Oils by Ultraviolet Fluorescence 1 to 8000 ppm
D6428-99, recently renumbered D6920-03 Total Sulfur in Liquid Hydrocarbons and their Derivatives by Oxidative Combustion and Electrochemical Detection Range of diesel fuel samples used by the recent RR is 1ppm to 40 ppm
Precision results for diesel fuel:
Designation r R
D3120-96 0.08520(X + 0.6758)@ 1ppm @15ppm0.14 1.33 0.5152(X + 0.6758)@ 1ppm @15ppm0.85 8.07
D5453-00 0.02777(X + 28.158)@ 1ppm @15ppm0.81 1.20 0.3659(X + 2.1101)@ 1ppm @15ppm1.14 6.26
D6428-99 (D6920-03) 0.1960(X + 0.61789)@ 1ppm @15ppm0.32 3.06 1.3028(X + 0.61789)0.9022@ 1ppm @15ppm2.01 15.55