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Submissions Received on the Proposed Amendments to the Sulphur in Diesel Fuel Regulations

Vehicle and Engine Manufacturers


Canadian Vehicle Manufacturers' Association

Dear Mr. McEwen.

Re: Canada Gazette Notice Part 1 - Regulations Amending the Sulphur in Diesel Fuel Regulations published October 2, 2004

The Canadian Vehicle Manufacturers' Association (CVMA) has reviewed the Canada Gazette Notice regarding the amendments to the Sulphur in Diesel Fuel Regulations of October 2, 2004 and are generally supportive of the changes. CVMA offers the following comments for your consideration:

With respect to Section 1(1), a definition for biodiesel fuel should be included in the regulation. The definition should clearly indicate that biodiesel fuel intended to include biodiesel/diesel fuel, blends.

Also, the proposed regulation does not address labeling for off-road diesel. The regulation should have requirements with respect to the labeling of this fuel to prevent misuse for on-road diesel vehicles. Given the current practice of using dyed off-road diesel in vehicles designed for on-road use, there is the potential to impact the Tier 2 and heavy-duty engine/vehicle emission control technology on new diesel vehicles. This precise new diesel emissions technology will not achieve the intended environmental benefits of the On-Road Vehicle and Engine Emission Regulations if operated on off-road, dyed diesel. Environment Canada should take the necessary steps to warn individuals about the impacts of using dyed off-road diesel on advanced emission control technology on-road diesel vehicles.

CVMA trusts that our comments will be given serious consideration. Should you have any questions, please do not hesitate to contact the undersigned.

Yours sincerely.


EMA - Engine Manufacturers Association

December 1, 2004

Bruce McEwen
Chief, Fuels Division
Air Pollution Prevention Directorate Via E-mail (Bruce.McEwen@ec.gc.ca)
Environmental Protection Service
Department of the Environment,
Ottawa, Ontario
K1A 0H3

Re: Canada Gazette, Part I, October 2, 2004, Proposed Amendments to the Federal Sulphur in Diesel Fuel Regulations

Dear Mr. McEwen:

The Engine Manufacturers Association (EMA) is a national trade association representing the world's leading manufacturers of internal combustion engines. Among EMA's members are the principal manufacturers of diesel-fueled non-road engines.

EMA submitted written comments on the August 2003 discussion draft titled "Reducing the Level of Sulphur in Canadian Off-road Diesel Fuel". EMA is pleased to provide comments on the October 2, 2004, Canada Gazette, Part I notice regarding the Proposed Regulations Amending the Sulfur in Diesel Fuel Regulations.

EMA is a strong proponent of the desulfurization of all fuels in order to improve engine emission control. Reductions in diesel fuel sulfur not only will enable the use of technology necessary to reduce emissions from new engines, but they also will provide emission reduction benefits to the existing engine fleet, an important benefit that improves overall air quality. EMA strongly supports Environment Canada's proposal to align Canadian requirements for sulfur in diesel fuel with those of the U.S.

EMA has submitted comments on Environment Canada's proposed "Off-Road Compression-Ignition Engine Emission Regulations" which will establish emission standards aligning with existing EPA Tier 2 and 3 standards. Furthermore, we recognize Canada's intent to align with EPA's Tier 4 standards. We support Canada's efforts to align Canadian emissions standards with the U.S. However, compliance with these standards is dependant on a systems approach and advanced engine design, advanced exhaust control technologies, and improved diesel fuel standards all are needed. The importance of the alignment of fuel standards cannot be overemphasized. Nonroad diesel fuel sulfur levels must be improved dramatically for Tier 3. Moreover, current levels of sulfur in commercially available diesel fuel preclude the use of advanced aftertreatment technology that will be necessary to comply with the very stringent U.S. EPA Tier 4 NOx and PM levels with which Canada intends to align.

EMA supports a simple regulation requiring Canadian non-road diesel fuel to meet a 500 mg/kg limit starting 2007, reduced to a 15 mg/kg limit starting 2010.

Low Sulfur (500 ppm) Fuel Is Necessary for Tier 3

In order to ensure the successful implementation of Tier 3 standards in Canada, Environment Canada must assure that nonroad engines operate in-use on the same or better fuel quality as the corresponding on-highway engines with the same or similar technologies. One of the key emission control technologies that is expected to be adapted for use with nonroad engines, is exhaust gas recirculation ("EGR"). EMA and its members have established the linkage between fuel sulfur content, sulfuric acid formation, and the resultant impacts on engine wear, maintenance and durability. The impacts of fuel sulfur on EGR systems and engine wear do not occur from isolated usage, but from long-term exposure to the highly corrosive exhaust gases associated with the combination of fuel with high levels of sulfur. In that regard, EMA has demonstrated that engines with EGR systems must be assured of operating, over their lives, on diesel fuels with sulfur levels that average substantially less than 500 ppm.

Nonroad engines with EGR systems will not meet either manufacturers' or customers' durability requirements if the current sulfur level of nonroad diesel fuel is maintained. Moreover, the very stringent Tier 3 standards will not be achievable with current nonroad diesel fuel and, thus, it is essential that nonroad diesel fuel sulfur levels be reduced to 500 ppm and lower at the earliest possible date.

EMA supports Environment Canada's proposed interim limit of 500 mg/kg beginning no later than June 2007. We oppose any delay for Northern Regions because of the impacts discussed above.

Ultra Low Sulfur (15 ppm) Fuel Is Necessary for Tier 4

It is well known that the level of emission reductions required under EPA's Tier 4 Rule will drive the use of NOx aftertreatment, catalyzed particulate filters, and other advanced aftertreatment technologies. In order to use those technologies effectively, and ensure the durability of nonroad engine and aftertreatment systems over their required useful lives, diesel fuel sulfur levels must be near zero and no higher than 15 ppm.

Sulfur content is the fuel property that has the greatest overall impact on engine systems design and future emissions capability. Fuel sulfur levels have a direct impact on the appropriate formulations for lubricating oil, lubricating oil life, engine durability (including pistons, rings, liners, valves, turbochargers), fuel system life, the amount of EGR that can be employed on an engine, and the life and effectiveness of various aftertreatment devices.

Two exhaust control strategies are potentially available to reduce PM emissions in nonroad engines: oxidation catalysts and particulate filters (traps). "Low-sulfur" diesel fuel with a 500 ppm sulfur level to be introduced for nonroad commercial use in the U.S in 2007 will, nonetheless, preclude the introduction and use of the most effective particulate filter technology and significantly impede the effective use of other catalyst-based PM-control technologies necessary to meet the Tier 4 standards.

Particulate filter technology also can be very effective at reducing PM emissions to extremely low levels, provided that sulfur in the fuel is greatly reduced. Advanced particulate filter technologies utilize pre-filter catalysts to convert NO to NO2 which, because it is a strong oxidant, reduces the temperature required for filter regeneration. Unfortunately, the pre-catalyst also converts fuel sulfur to sulfate particulate which is not trapped by the downstream filter and which has a significant effect on tailpipe PM emission levels. A fraction (currently 1-3%) of fuel sulfur converts to sulfate during the engine combustion process, which is emitted as particulate and collected and measured as part of the PM test procedure requirements. The balance of fuel sulfur is emitted as gaseous SO2 and, even though it is not measured as tailpipe particulate, the majority is later converted to sulfate in the atmosphere.

Engine manufacturers expect that the use of advanced catalysts in particulate filter systems will increase the sulfate conversion rate of emission control systems to 40% or more, depending on engine operating conditions 1. The increased sulfate conversion rate of such emission control technologies represents a significant portion of the particulate emissions from nonroad engines.

Additionally, sulfur in the fuel can inhibit the NO to NO2 conversion process causing regeneration light-off temperature to increase outside the normal exhaust temperature range, with the result that the filter can become susceptible to plugging. This is particularly critical for light-duty applications, which generally operate at lighter loads and lower exhaust temperatures, and for heavy-duty applications that operate extensively at light loads and low speeds. As a result, ultra-low sulfur fuel is required in order to enable the effective use of particulate filter technology.

In addition, as recognized by EPA, current fuel sulfur levels inhibit the performance of the most promising aftertreatment technologies that have the potential to provide significant reductions in NOx emissions. In some cases, diesel fuel with a sulfur content anything other than near-zero levels is a complete barrier to the application of those technologies.

NOx adsorbers have the potential to attain ultra-low levels of NOx emissions. NOx adsorbers, however, are particularly sensitive to the presence of sulfur in diesel fuel. Sulfur converts to sulfate and the sulfate consumes the storage sites needed for effective NOx adsorption. Because sulfur is a cumulative poison in NOx adsorbers, such technology is not usable with current diesel fuel sulfur levels. Indeed, the implementation of NOx adsorbers systems is absolutely dependent upon readily available supplies of ultra-low sulfur fuel, as the ability of absorbers to store NOx effectively is extremely sensitive to the presence of any fuel sulfur.

EMA was part of a research program designed to evaluate various sulfur-sensitive technologies and obtain data on the sulfate conversion levels over a broad range of on-highway engine operating conditions. That program showed that there are no sulfur-tolerant aftertreatment technologies capable of meeting future emission standards and some technologies, such as NOx adsorbers, are so sensitive to fuel sulfur that they are judged to be not feasible without ultra-low sulfur diesel fuel. (For a more detailed discussion, see "Statement of the Engine Manufacturers Association," pp. 10-12, August 14, 2000, Docket No. A-99-06, Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle Standards; Highway Diesel Fuel Sulfur Control Requirements; Proposed Rules.)

EPA's Tier 4 standards that Canada intends to align with, will force the use of innovative and advanced technologies and will require significant product development, and improvement and use of advanced aftertreatment technologies, particularly in the area of NOx control. EPA has, in fact, recognized that the Tier 4 standards drive the use of NOx adsorbers and other advanced technologies to achieve those standards. All evidence suggests that NOx adsorber aftertreatment performs best in the absence of sulfur.

It should by noted that no harm is caused by the use of diesel fuel with a lower sulfur content than may be required by an engine and aftertreatment system. The use of a higher-than-required fuel sulfur level, however, is detrimental to the engine and to the aftertreatment.

EMA supports Environment Canada's proposed sulfur limit of 15 mg/kg beginning no later than June 2010. We oppose any delay for Northern Regions because of the impacts discussed above.

Marine and Locomotive Diesel Fuel Specifications

EMA supports the proposal to require commercial diesel fuel with a maximum sulfur content of 500 ppm for locomotive and marine usage beginning in 2007, with a final level of 15 ppm in 2012. The use of low sulfur fuel will have a beneficial effect on engine durability and maintenance requirements. In addition, the proposal will provide air quality benefits and will avoid the need for a more complex fuel distribution system (i.e. with three sulfur levels -- 15, 500 and >500 mg/kg).

Recommendations

EMA supports Environment Canada's efforts to align requirements for sulfur in non-road diesel fuel with the U.S. EPA. We support the proposed amendments requiring Canadian non-road diesel fuel to meet a 500 mg/kg limit starting no later than 2007, reduced to a 15 mg/kg limit starting no later than 2010 (except for locomotive and marine diesel fuel that would remain subject to the 500 mg/kg limit with a limit of 15 ppm beginning in 2012.) We oppose any delays for Northern Areas.

Please do not hesitate to contact me if you have any questions.

Respectfully submitted,


1  It should be noted that the higher conversion rate does not increase the concentration of sulfates in the atmosphere. Rather, the sulfate conversion that would otherwise take place in the atmosphere would now be expected to occur in the aftertreatment system. In other words, as the sulfate conversion increases in the engine system, sulfate formation in the atmosphere will decrease. Thus, there will be no new environmental impacts from sulfate conversion with the use of such catalyst technologies. What is important to focus on is that the only way to reduce sulfate in the atmosphere, whether generated in the engine, aftertreatment system or in the atmosphere itself, is to reduce sulfur in the fuel.

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