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Ultra-low sulfur diesel

Ultra-low sulfur diesel (ULSD) (also spelled “sulphur”) is a term used to describe a standard for defining diesel fuel with substantially lowered sulfur contents. As of October 15, 2006, most on-highway diesel fuel sold at retail locations in the United States and Canada is ULSD[citation needed].

The move to lower sulfur content is expected to allow the application of newer emissions control technologies that should substantially lower emissions of particulate matter from diesel engines, similar to changes that previously took place in the European Union. New emissions standards, dependant on the cleaner fuel, will apply in the United States beginning in model year 2007.


North America

United States

Ultra-low sulfur diesel was proposed by EPA as a new standard for the sulfur content in on-road diesel fuel sold in the United States since October 15 2006, except for rural Alaska. California required it since September 1 2006, and rural Alaska will transition all diesel to ULSD in 2010. This new regulation applies to all diesel fuel, diesel fuel additives and distillate fuels blended with diesel for on-road use, such as kerosene, however, it does not yet apply to train locomotives, marine, or off road uses. By December 1, 2010, all highway diesel will be ULSD. Non-road diesel transitioned to 500 ppm sulfur in 2007, and to ULSD in 2010. Locomotive and marine diesel also transitioned to 500 ppm sulfur in 2007, and to ULSD in 2012. There are exemptions for small refiners of nonroad, locomotive and marine diesel that allow for 500 ppm diesel to remain in the system until 2014. After December 1, 2014 all highway, nonroad, locomotive and marine diesel produced and imported will be ULSD.

The EPA mandated the use of ULSD fuel in model year 2007 and newer highway diesel fuel engines equipped with advanced emission control systems that require the new fuel. These advanced emission control technologies will be required for marine diesel engines in 2014 and for locomotives in 2015.

The allowable sulfur content for ULSD (15 ppm) is much lower than the previous U.S. on-highway standard for low sulfur diesel (LSD, 500 ppm), which not only reduces emissions of sulfur compounds (blamed for acid rain), but also allows advanced emission control systems to be fitted that would otherwise be poisoned by these compounds. These systems can greatly reduce emissions of oxides of nitrogen and particulate matter.

Because this grade of fuel is comparable to European grades and engines will no longer have to be redesigned to cope with higher sulfur content and may use advanced emissions control systems which can be damaged by sulfur, the standard may increase the availability of diesel-fueled passenger cars in the U.S. European diesels are much more popular with buyers than those available in the U.S.

Additionally, the EPA is assisting manufacturers with the transition to tougher emissions regulations by loosening them for model year 2007 to 2009 light-duty diesel engines.[1] As a result, Honda, Nissan, Subaru, Toyota, and others are expecting to begin producing diesel vehicles for the U.S. market to join those from Mercedes-Benz and Volkswagen.[2]

According to EPA estimates, with the implementation of the new fuel standards for diesel, nitrogen oxide emissions will be reduced by 2.6 million tons each year and soot or particulate matter will be reduced by 110,000 tons a year.

On June 1st, 2006, U.S. refiners were required to produce 80% of their annual output as ULSD (15 ppm), and petroleum marketers and retailers were required to label[3] diesel fuel, diesel fuel additives and kerosone pumps with EPA-authorized language disclosing fuel type and sulfur content. Other requirements effective June 1st, 2006, including EPA-authorized language on Product Transfer Documents and sulfur-content testing standards, are designed to prevent misfueling, contamination by higher-sulfur fuels and liability issues. The EPA deadline for industry compliance to a 15 ppm sulfur content was originally set for July 15, 2006 for distribution terminals, and by September 1, 2006 for retail. But on November 8, 2005, the deadline was extended by 45 days to September 1, 2006 for terminals and October 15, 2006 for retail. In California, the extension was not granted and followed the original schedule. As of December, 2006, the ULSD standard has been in effect according to the amended schedule, and compliance at retail locations was reported to be in place.

Sulfur is not a lubricant, however the process used to reduce the Sulfur also reduces the fuel's lubricating properties. Lubricity is a measure of the fuel's ability to lubricate and protect the various parts of the engine's fuel injection system from wear. The processing required to reduce sulfur to 15 ppm also removes naturally-occurring lubricity agents in diesel fuel. To manage this change ASTM International (formerly the American Society for Testing and Materials) adopted the lubricity specification defined in ASTM D975 for all diesel fuels and this standard went into effect January 1, 2005. [4]

The refining process that removes the sulfur also reduces the aromatic content and density of the fuel, resulting in a minor decrease in the energy content, by about 1%. This decrease in energy content may result in reduced peak power and fuel economy. The reduction is only slight and will likely go unnoticed.

ULSD will run in any engine designed for the ASTM D-975 diesel fuels.


Under Sulphur in Diesel Fuel Regulations (SOR/2002-254), the diesel fuel produced or imported was reduced to 15 mg/kg after 2006-5-31, followed by reduction of sulfur in diesel fuel sold for use in on-road vehicles after 2006-8-31, then reduction of sulfur in diesel fuel sold in the northern supply area for use in on-road vehicles after 2007-8-31.

An amendment titled Regulations Amending the Sulphur in Diesel Fuel Regulations (SOR/2005-305) added following deadlines:

  • concentration of sulfur in diesel fuel produced or imported for use in off-road engines shall not exceed 500 mg/kg from 2007-6-1 until 2010-5-31; and 15 mg/kg after 2010-5-31.
  • concentration of sulfur in diesel fuel sold for use in off-road engines shall not exceed 500 mg/kg from 2007-10-1 until 2010-9-30; and 15 mg/kg after 2010-9-30.
  • concentration of sulfur in diesel fuel sold in the northern supply area for use in off-road engines shall not exceed 500 mg/kg from 2008-12-1 until 2011-11-30; and 15 mg/kg after 2010-11-30.
  • concentration of sulfur in diesel fuel produced or imported for use in vessel engines or locomotive engines shall not exceed 500 mg/kg from 2007-6-1 until 2012-5-31; and 15 mg/kg after 2012-5-31.

An amendment titled Regulations Amending the Sulphur in Diesel Fuel Regulations (SOR/SOR/2006-163) allowed diesel with sulfur content up to 22 mg/kg to be sold for onroad vehicles between 2006-9-1 to 2006-10-15, then 15 mg/kg after 2006-10-15. This amendment facilitated the introduction of 15 mg/kg sulfur diesel fuel for on-road use in 2006, by lengthening the period between the dates that the production/import limit and the sales limit come into effect. It provided additional time to fully turn over the higher-sulfur diesel fuel inventory for on-road use in the distribution system. The requirements of the Regulations were aligned, in level and timing, with those of the U.S. EPA.



Since 2002, (mainland) China has limited sulfur in diesel fuel to 2000 ppm, with limits of 500 ppm applied for certain cities.[5]

Hong Kong

In 2000-7, Hong Kong became the first city in Asia to introduce ULSD, with sulfur content of 50 parts per million (ppm). In addition, new petrol private cars were asked to meet Euro III standards from 2001.

Since the introduction of the law, all fuel station started supplying ULSD since 2000-8.

Sulfur content of regular diesel fuel was lowered from 500 ppm to 350 ppm in 2001-1-1.

As part of the ULSD package, Hong Kong government lowered the tax for ULSD from HK$2.89 to $2.00 per litre in June 1998. The temporary concession was subsequently extended to 2000-3-31 then to 2000-12-31.

On 2000-6-19, under Report of the Subcommittee on resolution under section 4(2) of the Dutiable Commodities Ordinance (Cap. 109), ULSD fuel tax was lowered to HK$1.11 per litre between 2000-7-7 and 2000-12-31, then increased to $2 in 2001, then $2.89 per litre in 2002-1-1. The resolution was passed on 2000-6-27.

Under LC Paper No. LS 37/00-01, which passed in 2000-12-20, the $1.11 per litre tax rate was extended to 2001-6-30.

Under LC Paper No. LS 115/00-01, which passed in 2001-6-20, the $1.11 per litre tax rate was extended to 2002-3-31, then the tax would be raised to $2.89 per litre afterwards.

Under LC Paper No. LS 67/01-02, which passed in 2002-3-13, the $1.11 per litre tax rate was extended to 2003-3-31.

Under LC Paper No. LS 76/02-03, which passed in 2003-3-19, the $1.11 per litre tax rate was extended to 2004-3-31.

Under LC Paper No. LS 59/03-04, which passed in 2004-3-24, the $1.11 per litre tax rate was extended to 2004-12-31.


Beginning in 2007, Taiwan has limited sulfur in diesel fuel to 50 ppm, equivalent to the Euro IV standard.[6]


The National Environment Agency (NEA) defines ultra low sulfur diesel (ULSD) as diesel fuel with less than 50ppm, or 0.005 per cent, sulfur content.

On 16 Jun 2005, NEA announced that the use of ULSD would be mandatory beginning 1 Dec 2005. The regulation also offered tax incentives for Euro IV diesel taxis, buses and commercial vehicles between 1 Jun 2004 and 3 Sep 2006, pending a mandatory conversion to Euro IV-compliant vehicles in 2007.

European Union

At the European Union level, the “Euro IV” standard applies since 2005, which specifies 50 ppm maximum quantity of sulfur in diesel fuel for most highway vehicles[7]; ultra-low sulfur diesel with a maximum of 10 ppm of sulfur must “be available” from 2005 and is actually widely available. A final target (to be confirmed by the European Commission) of 2009 for the final reduction of sulfur to 10 ppm, which will be considered the entry into force of the Euro V fuel standard. In 2009, diesel fuel for most non-highway applications is also expected to conform to the Euro V standard for fuel. Various exceptions exist for certain uses and applications, most of which are being phased out over a period of several years. In particular, the so-called EU accession countries (primarily in Eastern Europe), have been granted certain temporary exemptions to allow for transition. Certain EU countries may apply higher standards or require faster transition.[8] For example, Germany implemented a tax incentive of €0.015 per litre of "sulphur free" fuel (both gasoline and diesel) containing less than 10 ppm beginning in January, 2003 and average sulphur content was estimated in 2006 to be 3-5 ppm. Similar measures have been enacted in most of the Nordic countries, Benelux, Ireland and the United Kingdom to encourage early adoption of the 50 ppm and 10 ppm fuel standards.[9]


Since 1990, diesel fuel with a sulfur content of 50 ppm (0.005%) has been available on the Swedish market. From the year 1992, production started of a diesel fuel with 2 to 5 ppm of sulfur and a maximum of 5% by volume aromatics. There are certain tax incentives for using this fuel and from about year 2000, this low aromatic, low sulfur fuel has achieved 98-99% penetration of the Swedish diesel fuel market. Now RME (rape seed methyl ester, also called biodiesel) is often usen as lubricant, but there are also synthetic super lubricants available on the market.

Since 2003, a zero sulfur and very low aromatic content (less than 1% by volume) diesel fuel has been made available on the Swedish market under the name EcoPar. It is used wherever the working environment is highly polluted, like where diesel trucks are used in confined spaces such inside boats in harbours, inside storage houses, during construction of road and rail tunnels & in vehicles that are predominantly run in city centres, etc.

Central and Eastern Europe (“Accession Countries”)

From 2008, most accession countries are expected to have transitioned to diesel fuel with 10 ppm sulfur or less. Slightly different times for transition have applied to each of the countries, but most have been required to reduce maximum sulfur content to below 50 ppm since 2005.[1] Certain exemptions are expected for certain industries and applications, which will also be phased out over time. Compared to other EU countries, ULSD may be less widely available.

Russia / CIS / Former Soviet Union

As of 2002, much of the former Soviet Union still applies limits on sulfur in diesel fuel substantially higher than in Western Europe. Maximum levels of 2,000 and 5,000 ppm are applied for different uses. In Russia, lower maximum levels of 350 ppm and 500 ppm are enforced in certain areas, particularly Moscow and St. Petersburg. Euro IV fuel with a concentration of 50 ppm or less may be available at certain fueling stations, at least in part to comply with emissions control equipment on foreign-manufactured cars and trucks. Euro IV diesel may in particular be available at fueling stations selling to long-distance truck fleets servicing import and export flows between Russia and the EU.[2]


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  8. ^ Presentation on mitigating fuel emissions, Noxious effects
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See also

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Ultra-low_sulfur_diesel". A list of authors is available in Wikipedia.
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