Low Sulfur Fuel Lubricity

I've been reading that by 2007, we will be using diesel juice with much lower sulfur content, comparable to fuel used in much of western Europe. It appears that the new fuel will have much lower lubricity than what we currently use in the U.S. I have a 2003 Jetta TDI and a 1997 Dodge truck with a Cummins engine, both with lotsa miles.

Does anyone know what measures fuel producers will take (if any) to increase lubricity in the low sulfur fuel? I know
that even a small percentage of biodiesel in conventional diesel fuel increases lubricity tremendously, but I doubt biodiesel manufacturing capability could begin to keep up with potential demand for the stuff as a fuel supplement,
considering the number of big rigs carrying our daily everything.

I'm interested in hearing the current info on this topic.
Thanks for your posts.

Well, there was a piece in the local newspaper about this inactive seed squeezing plant in eastern MT, that used to process sunflower seeds to oil, that was acquired by a new coop for the express purpose of producing seed oil for biodiesel. Rapeseed, canola...etc. People in agribusiness are thinking about it! Also, with these prices, methanol in all gasoline is gonna happen!

I thought there were petrochemical additives that they would add, but that's mostly my assumption from hear-say and part-truths. So I don't know, but that's what I was expecting.

Yeah, I figured that the methanol issue would do nothing to help biodiesel production, especially with influential farm state reps doing their best to promote methanol as a fuel and gasoline additive. Good sense loses out to political
priorities again.

The link between fuel sulfur content and fuel lubricity is one that has been dealt with a long time ago by the refiners.

In a nutshell, sulfur isn't actually responsible for the lubricity, but there's a public perception that it is, because there was a problem years ago when a process they used at the time to remove sulfur had the secondary, undesired effect of removing unrelated compounds that affected the lubricity. The process was changed to not do this, and is now a non-issue. ULSD shouldn't cause any trouble; it will have to meet ANSI standards including lubricity.

The link between fuel sulfur content and fuel lubricity is one that has been dealt with a long time ago by the refiners.

In a nutshell, sulfur isn't actually responsible for the lubricity, but there's a public perception that it is, because there was a problem years ago when a process they used at the time to remove sulfur had the secondary, undesired effect of removing unrelated compounds that affected the lubricity. The process was changed to not do this, and is now a non-issue. ULSD shouldn't cause any trouble; it will have to meet ANSI standards including lubricity.

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That's about a 1/4 right.

When diesel is hydrotreated to remove sulfur, some lubricity is lost. This happened in 1993 for low sulfur and will happen again for ultra low sulfur.

Lubricity of current low sulfur is borderline according to the newly introduced ASTM spec. During 2005, fuel producers will begin additizing deisel with lubricity additives. By the time ultra low comes around in 2006, all fuel will be additized.

Sulfur has been reduced for over 10 years... in 2006 it will just be a minor reduction, relatively.

What really hurts lubricity from what I've read is going for California type low aromatic fuels. The aromatic content of the fuel helps to clean, codition, and lubricate the seals in the fuel injector pump- especially on older diesels, but they also tend to reduce the cetane (combustability) of the fuel, meaning they don't burn as clean.

Engines will "run" just fine on any of these fuels, at least for a while, but there's no guarantee they will last of course. The cheapest way to "solve" the problem is to use a small amount of an additive like Power Service or Stanadyne at every fillup, or use a small amount of biodiesel (about 2-5 percent works sufficiently).

A 97% reduction is minor? Moot point, because 100% would be even better--sulfur serves no useful purpose in diesel fuel. None.

Engines will "run" fine on the new ULSD AND they will last even longer than they do now, with or without additives to make up for the lost lubricity that the refineries will have already 'made up for'.

(mag) Sulfur has been reduced for over 10 years... in 2006 it will just be a minor reduction, relatively.

Click to expand...

A 97% reduction is minor? Moot point, because 100% would be even better--sulfur serves no useful purpose in diesel fuel. None.

Engines will "run" fine on the new ULSD AND they will last even longer than they do now, with or without additives to make up for the lost lubricity that the refineries will have already 'made up for'.

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Is this most recent round of reduction 97% of what it was ten years ago, or what it is now?

What I'm getting at is how much sulfur was in the fuel ten+ years ago and how much is in it now and how much will there be with ULSD? The amount that it will be reduced to acheive ULSD may be small relative to what we started with ten+ years ago.

I think the limit in place before the first reduction in 1992? was set at 5000 PPM (5/1000 or half a percent), and this was the same for home heating oil and off-road diesel (then "off-road" only meant no tax was paid). Then around 1992 the sulfur cap for on-road diesel was set to 500 PPM and I think diesel runs at about 300 PPM on average. The next round in late 2006 (to comply with the 2007 MY introduction) is at 15 PPM.

--Nate

The diesel fuel you can purchase at any Arco station in California displaying the "ECD" decal on the diesel pump is ULSD (15 ppm) with a Cetane of "Cetane index (typically) 52.5" and "Cetane number (typically) 54". This is out of their Product Specification-West Coast ECD. At this time it is only available in California for consumer usage. Commercial users across the Country can obtain this ULSD.

Sulfur will be reduced from 500ppm to 15ppm, a 97% reduction. Last time, it was reduced from 5000ppm to 500ppm.

Primrose makes an additive to address the lubricity issue for ULSD. I think it's called 402 or 502. Has no other performance claims - cetane, gel point, etc. so ...
FWIW

It's going to be interesting on how the companies differentiate themselves when all fuel is ULSD. Right now the only one in my area is BP Supreme, but when everyone has low sulfur, it's going to take some convincing for me to not just buy the cheapest diesel from a high volume station.

BP Sumpreme is not ULSD. It is LSD like almost every other #2 diesel on the market. Sumpreme is a 50 cetane fuel while most are low 40's.