Tanks that once stored high sulfur fuels can contaminate low sulfur fuels.

[NNadir]

Recently we were discussing in this forum the new low sulfur diesel fuels that are planned. On that topic, I thought this interesting paper from the ASAP section of the journal Energy and Fuels might be germane.

Personally I am hoping for a complete end to petroleum based fuels of all kinds, but I think I'll have some time to wait.

"The United States Environmental Protection Agency (EPA) has issued Tier 2 regulations that progressively limit the future concentrations of sulfur in motor vehicle fuels.1-3 The European Commission has implemented similar regulations. The goal is to reduce the sulfur content of these fuels from the 300 to 500 microgram/mL range down to the 15-30 microgram/mL range...

...There is a concern that transporting and storing low and high-sulfur fuels sequentially in the same pipelines and storage tanks may lead to contamination of the lower-sulfur fuels by residual sulfur.3,4 A report issued by the U.S. Department of Energy, Energy Information Administration discusses the potential contamination problem in detail and notes that, in the case of ultralowsulfur diesel (ULSD) fuel, approximately 4.4% of the volume will need to be downgraded because of sulfur contamination from the distribution system.4...

...In our own laboratory, we experienced a situation where a no-sulfur fuel was transported back and forth to another facility and stored in what were supposedly clean containers, yet at the end of the sample exchange the fuel was found to have been contaminated by sulfur. The potential for sulfur contamination of trailing hydrocarbon fluids in pipelines used to carry sour (high sulfur)hydrocarbon fluids was recognized some time ago and has been addressed by several patents...6,7"

(The quotation was edited to add the term "micro" where the mu symbol, which is not supported by this editor, was.)

The abstract is here: http://pubs.acs.org/cgi-bin/abstract.cgi/enfuem/asap/abs/ef050024x.html

[firefox]

1. Wait 50 years

Personally I am hoping for a complete end to petroleum based fuels of all kinds, but I think I'll have some time to wait.

It will all be gone in short order.

[NNadir]

2. I don't have 50 years. Maybe no one does.

[Massacure]

3. Pipelines only have so much sulfer residue in them though.

[hatrack]

4. Friend of mine used to be work for Koch Industries

He mentioned the same problem the last time we talked.

Given the current pipeline infrastructure, I hope we don't have to end up settling for "cleaner" diesel instead of the cleanest low-sulfur fuel possible.

[NNadir]

5. If you read the paper, the pipes most a risk, unsurprisingly, are copper

alloys. Copper has a high affinity for sulfur compounds in general, an effect that has important consequences in biochemistry as well as in fuel chemistry.

Here is something else interesting in the paper. FT diesel (Fischer-Tropsch or synthetic diesel) is described as having zero sulfur. If so, the FT diesel oil used is unlikely to have been made from coal which of course, is usually packed with sulfur.

In any case, it does seem that sulfur will be in fuels for some time even if it is removed by some means. This may not seem like much, but it has important implications for catalyst performance. It also has important air pollution and aerosol implications, and of course implications in acid rain.