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Ultra Low-Sulfur Diesel Arrives

API-recommended pump label for ULSD.

Sunday, October 15 marked the official arrival of new ultra-low sulfur diesel (ULSD) in US retail pumps. ULSD contains a maximum of 15ppm sulfur, down from the 500ppm maximum of the low-sulfur fuels it replaces.

ULSD use will immediately cut soot emissions from any diesel vehicle by 10 percent. Combined with a new generation of engines hitting the road in January, it will enable emission reductions of up to 95% percent, according to the Natural Resources Defense Council (NRDC) and the Diesel Technology Forum (DTF).

Diesel is the invisible force that moves the American economy, but until now it has also been a big polluter. Combining the new fuel with cleaner and more energy-efficient engines will mean healthier air and help reduce our dependence on oil.

—Richard Kassel, head of NRDC’s Clean Fuels and Vehicles Project

Improvements in both the fuel and the engines are required under new federal rules adopted by the Clinton administration and subsequently endorsed and implemented by the Bush administration. The policy was almost a decade in the making, and involved close collaboration between regulators, oil refiners, engine manufacturers and public health advocates to achieve a cost-effective solution.

The diesel clean-up rivals the removal of lead from gasoline a generation ago. Sulfur hampers exhaust-control devices in diesel engines, much in the same way that lead once impeded the effectiveness of catalytic converters on gasoline cars.

Since the fuel has to end up at the pump with a maximum 15 ppm, refiners are producing it at a slightly lower concentration to allow for some margin of error in production and potential product contamination in the distribution system. ULSD shipped in a pipeline, for example, could pick up an extra couple ppm sulfur.

Refiners have invested in their hydrotreaters—and in additional hydrogen capacity—to produce the fuel.

Conventional hydrotreating puts heated feedstock and hydrogen into a catalyst-laden reactor to separate sulfur from hydrocarbon molecules. The hydrotreatment process can desulfurize streams at multiple points in the refining process: directly following crude distillation (“straight-run” streams); streams coming out of fluid catalytic cracking (FCC) units; and hydrotreating the heavier streams that go through a hydrocracker.

Catalyst requirements for ULSD production. Click to enlarge. Source: Chevron

Refineries with hydrotreaters are likely to achieve production of ULSD on straight runs by modifying catalysts and operating conditions. Chevron, as an example, found that producing 10ppm ULSD required about three-times the catalyst volume as did conventional LSD (500ppm). Achieving 3ppm diesel required about 25% more catalyst than for 10ppm, or a reduction in capacity of about 20%.

Desulfurizing the remainder of the distillate streams is expected to pose the greatest challenge, requiring either substantial revamps to equipment or construction of new units.




Great news... now where is the car that i can put this into? I can't afford an e-class, shame though.


At what point do you hit diminishing returns? From my reading here it is extremely expensive and impractical to winnow out every last ppm of sulfur, at least with present technology.

Rafael Seidl

Cervus -

you're right, though much depends on the relative impact on prices at the pump. Here in Austria, where fuel taxes are high, diesel fuel already meets the 2010 EU directive calling for 10ppm, with 3-4ppm typical in actual samples. Another reason is that between 1945 and 1955 the Russians forced us to trade in our own sweet crude for some extremely sour crude (up to 20% sulphur) of theirs. This led to the deployment of desulphurization equipment decades before anyone else needed to. As a result, our refinery has more experience than most with the Claus process and can handle any crude from anywhere in the world.

US refineries, many previously saddled with antiquated equipment, are now becoming more flexible as well.

The direct benefits of USLD are direct improvements to air quality incl. reduced acid rain damage. Indirectly, it facilitates the introduction to the US market of NOx aftertreatment devices for diesel engines. NOx store catalysts are especially prone to sulphur poisoning. The purge process neccessary to eliminate sulphur that has been adsorbed requires very high temperatures and reduces both the efficacy and the life expectancy of the device a little bit on each occasion.

SCR catalysts are not susceptible to poisoning but the pre- and post-oxycats last much longer on low-sulphur fuel.


" Combining the new fuel with cleaner and more energy-efficient engines will mean healthier air and help reduce our dependence on oil."

I don't think this will reduce our dependence on foreign oil if no new engines are available to run the stuff and I haven't heard anyone claim this will improve mileage in the engines that can run it.

Is it accurate to say that this drastic reduction in sulfur will only reduce soot formation by 10% in older engines? If so we will practically have to turn our fleet over to notice the benefits.

I am disappointed because when I heard about the switch to ULSD I thought it would mean all these sweet european diesels would be able to meet our specs and I could actually reduce our dependence on foreign oil. I had my eye on a ford focus wagon. I didn't realize they were going to adopt the world"s toughest emission standards too. Looks like this is a victory for the cleaner air crowd, but the air quality didn't bother me before.




I am sure the paint industry argued that it was far exensive to remove lead from paint, also -- for 200 years after Ben Franklin found it was killing people. I suppor JRod never suffered from lead poising either. Well, maybe a little bit.


Adopting the worlds strictest emissions standards means taking the lead. Good for the politicians on this one! Necessity is the mother of invention.

When all have to meet the same lofty goals, that evens out the playing field. All have to excell to survive. It raises the bar. No longer does a bean counter design an engine. Things are no longer buisness as usuall. The engineers hired finally get to try their creative ideas that the companies pay them for. If they don't the conpany can no longer do buisness. Give the engineers the power to decide how to solve the problems and you get a better product. When I am in NYC and see their new busses with their "Clen Diesel Technology" signs, it really has made a hugh difference from the street. You don't get that awfull diesel puke belched at you.

Maybe put another way, cream rises to the top and now the U.S. has the cleanest diesels in the world. That will be the truth with the new 2007/2010 standards. Consumers will respond. 6000RPM and 100HP/Liter are now in production with awsome torque and mileage. Consumers will respond! That Clanky Smelly Slow Unpleasant diesel is gone and in a few years will have been replaced by the new generation. I'm all for it! Ballsy move! Hey B20 in an engine like that nationally is a great start. Now go and HUGH A PALM TREE!!!... :-)


All well and good but ULS diesel still derives from a non-renewable resource. The potential to get caught up in the cleaner air euphoria may dilute the need to keep growing our biofuels initiative.

Hopefully this fuel will become available for he millions of marine diesels as well. Good work NRDC!


At what point do you hit diminishing returns?

With this transition, you're cutting out 97% of the sulfur. Hardly a small improvement.


Sulfur components are responsible for most of familiar diesel fume smell. With ULS diesel smell(or stink) from diesel exhaust will be vastly diminished, yet PM and especially smog-forming NOx will remain almost the same.

BTW, ULSD has nothing to do with current reduction in diesel emission. First emission standards for bus and heavy truck engines went into effect in1988, and second extremely tight set was adopted beginning from 2004. To meet 2004 standards, engine manufacturers have to redesign their engines almost entirely. High-pressure common rail injection, electronic control, EGR, OBD, variable geometry turbochargers, Miller cycle, multi-event fuel injection, to name a few. 2004 compliant diesel engine differs from previous generation engine like jet fighter differs from biplane. 2004 and later diesel engines emit 20 times less harmless emissions, on a pair with tightest European and Japanese standards. Yet engine modifications reached their limits, and further reduction in emissions, mandated in US from 2007 (Europe decided to stay with more lenient standards for at least couple of years) will require adoption of aftertreatment devices. ULSD is necessary for proper operation of such a devices.

For clarification I would like to note:

1) These emission standards are for buses (currently even more stringier) and heavy trucks only, with off-road diesel engines following closely. Comparable tight standards for marine (internal and coastal waters only, ocean going ships are out of reach of US government jurisdiction) and locomotive diesel engines are more distant. Stationary diesel engines are subject for tight emission standards even longer that heavy trucks.

2) More lenient for diesel engines emission standards are not applicable for cars and light duty trucks beginning from 2007 for all US, 10 states lead by California adapted this beginning from 2006. No existed diesel-powered car is certified to be sold in US (Canada coming to this too). My bet is that we will more likely see hydrogen economy then conquista of US market by European “clean diesel”.

3) As any emission legislation, it has no power on already existed engines. Pre-standard engines will stink to the end of their useful life.


>>1) These emission standards are for buses (currently even more stringier) and heavy trucks only, with off-road diesel engines following closely. Comparable tight standards for marine (internal and coastal waters only, ocean going ships are out of reach of US government jurisdiction) <<

California is already trying to dictate new cleaner burning fuels for cargo ships and oil tankers.


>Great news... now where is the car that i can put this into? I can't afford an e-class, shame though.

How about a Volkswagen TDI? That's what I have, and TDI owners have been talking about ULSD for ages...


"(currently even more stringier)"

come on..."stringier" isn't even a word :)



Government of particular country does not have right to regulate emissions of ocean going merchant vessels. It is strictly responsibility of International Maritime Organization (IMO), and their emission regulation is very lenient. Some countries are trying to by-pass this problem, like imposing higher port fees for polluting vessels, or working on regional agreements such as low-sulfur fuel requirement for Baltic Sea. I would certainly like to see merchant ships switching to low-sulfur bunker oil and NOx reduction measures when approaching coastal waters.


Sorry. English is not my first language, not even second.


Ive heard of a huge diesel retrofitting (ie cats and DPFs)projects for earlier diesels. Surprised(not really) you missed that Andrey.

Sid Hoffman

Biodiesel is 0ppm. Chevron is trying to avoid the fact that we have a massive need for biodiesel by failing to point out the fact that we need to get away from this idea that crude oil - especially the nasty "sour" high sulpher crap we get from Canada ane Mexico - is the fuel of the future. Biodiesel contains no sulpher and at the very least a 50/50 mixture of 10ppm petro and 0ppm BD would give you a net result of 5ppm without even having to refine the crude any more than was needed for the 10ppm output.


I heard about these projects too. And about fuel cells too. The truth is no DPF or cat will survive old dirty diesel engine retrofit any longer that it takes to run couple of tests and report optimistic PR.


Looks like we have rivers running biodiesel feedstock which are discharged because evil Chevron does not want to refine it into biodiesel. Check in your grocery shop how much costs gallon of canola oil before you decide to use it to substitute regular diesel.


JRod, Where it will make a difference is in the trucking fleets,buses etc. This fuel in combo with hydrogen reformer/injector would result in greater efficiency and cleaner emissions.New systems that avoid the need to run main engine for cab idle neeeds and reefer operations chip away at the prob even more.In the US the biggest bang for the buck is in commercial diesel fleet.
I do however share your frustration in the delay in getting diesel fleet for consumers.

fyi CO2

The EPA is going to insure that ULSD fuel ends up at the pump with a maximum 15 ppm? How long is it going to take to replace the majority of 2006 and older diesel trucks to realize emission reductions of up to 95% percent? Of course many carriers are rushing to buy the older, cheaper, dirtier 2006 inventory remaining.

PS: JRod, your subjective air quality analysis is remarkable -do you live in a bubble?


Anyone see a price increase on diesel (I assume we are all seeing ULSD now at the pump). Round NJ diesel seems to be running 30-50 cents at a premium to gasoline and about the same price it has been for a good part of the year. Maybe the drop in prices and the heating oil/ULSD balanced out.


Biodiesel is 0ppm.

I think you mean SVO and WVO. Biodiesel has low sulfur of varying amounts, depending on the type.


Heavy trucks sold from 2004 are already quite clean. And you are right, there always is spike in truck sales in couple of months before new emission regulation kicks in.


Andrey, you wrote:

"My bet is that we will more likely see hydrogen economy then conquista of US market by European 'clean diesel'."

Problem is, the DaimlerChrysler "BlueTec" system does meet even the CARB 2009 diesel emission standards, but you need that complicated kludge of injecting a urea solution into the exhaust to lower the NOx in the exhaust. Yep, the solution won't come from Europe.

But it will come from Japan. Honda recently unveiled a new type of diesel emission control where the exhaust passes through a chamber with a layer of electrically charged gas in plasma form, which reduces NOx gases to simple NO2, easily removed by current catalytic converter designs. This allows the engine to meet CARB 2009 standard without having to lug around a tank of urea solution. Expect Honda to offer the engine in 2.2-liter I-4 and 3.2-liter V-6 form within two years on their models sold in the USA.


My info is that ULSD does NOT have to be sold till 12/31/2010. If you post 15 ppm on your pump, you must sell that. Also most 2007 trucks are using pre 2007 motors.


"Combining the new fuel with cleaner and more energy-efficient engines will mean healthier air and help reduce our dependence on oil."

I'm not going to wade in with my very against-the-grain views on air quality gains vs financial burdens. But whatever gains are said to be made about ULSD, meeting our goal towards energy independence is certainly NOT one of them. As far as that is concerned, this is certainly a step in the other direction.

I'm an owner-operator who has recently purchased a truck with the new ULSD-compliant engines. This engine cost me about $10K more from the get-go. Fuel mileage has been atrocious; going from 6.4mpg on my old worn-out rig to 5.3mpg with the ULSD engine. These numbers are fairly typical from what I've heard from numerous carriers and operators.

And this isn't pure anecdote. This warning about poor fuel mileage has always been warned -- inexplicably, as a mere afterthought or footnote appended to the apparently all-consuming goal of lowering sulfur emissions. Well, this particular footnote is going to force the entire trucking industry to use 10-20% more fuel. And that should be put in large, capitalized, bold print next to any press release toting the "wonders" of ULSD.

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