Rec-Marine Diesel Rule Omits Fuel Desulfurization

Diesel Fuel News, Oct 1, 2001

Today's ordinary marine diesel fuel would continue to be used for emissions testing and compliance with U.S. EPA's proposed recreational marine diesel engine emissions limits that will kick-in between 2006-2009.

Nor will exhaust aftertreatment devices be required, EPA says in the new proposal just posted on its web site.

(See: www.epa.gov/otaq/regs/nonroad/pre91401.pdf)

EPA figures the marine diesel engines covered by the rule (37 kilowatts and larger) will simply adopt other Tier 2 off-road engine technology, employing electronic engine controls and turbocharging, rather than exhaust catalysts.

However, engine makers could earn "blue sky" credits by voluntarily building even cleaner engines. EPA doesn't say whether these would be feasible without exhaust catalysts and cleaner, ultra-low-sulfur fuel.

EPA says it doesn't care what fuels might be used in such engines, as long as they meet the limits.

For both the baseline and "blue-sky limits, the engine size categories EPA shows are expressed in kilowatts or displacement (liters/ cylinder):

Proposed Recreational CI Marine Emission Standards and
Implementation Dates
Subcategory                      HC   NOx    PM       CO
                                 g/kW-hr   g/kW-hr  g/kW-hr
power [greater than or equal       7.5      0.40      5.0
to] 37 kW
0.5 [less than ro equal to]
disp [less than] 0.9
0.9 [less than or equal to]        7.2      0.30      5.0
disp [less than] 1.2
1.2 [less than or equal to]        7.2      0.20      5.0
disp [less than] 2.5
disp [greater than or equal to]    7.2      0.20      5.0
2.5
Subcategory                      Implementation
                                      Date
power [greater than or equal          2007
to] 37 kW
0.5 [less than ro equal to]
disp [less than] 0.9
0.9 [less than or equal to]           2006
disp [less than] 1.2
1.2 [less than or equal to]           2006
disp [less than] 2.5
disp [greater than or equal to]       2009
2.5
Blue Sky Voluntary Emission Standards for Recreational
Marine Diesel Engines (g/kW-hr)
Rated Brake Power (kW)            HC NOx   PM
power [greater than or equal to]   4.0    0.24
37 kW displ. [less than] 0.9
0.9 [less than or equal to]        4.0    0.18
displ. [less than] 1.2
1.2 [less than or equal to]        4.0    0.12
displ. [less than] 2.5
2.5 [less than or equal to]        5.0    0.12
displ.
Source: US EPA