Coming in the wake of a seminal clean-diesel marine conference in Washington, DC, earlier this year (see Diesel Fuel News 2/18/02, p10), numerous "green" demonstration and test programs are about to get underway.
Examples:
# The U.S. Maritime Administration (MARAD) recently signed a research agreement with SCX Ferries to test-run a high-speed, low-emissions passenger hydrofoil, initially between San Diego and nearby Oceanside, Calif. This aims to help reduce nitrogen oxides (NOx) and particulate matter (PM) along California's heavily-traveled Interstate-5 commuter corridor. The project could expand to service between Los Angeles and San Diego.
Depending on actual delivery of the first vessel (it's being shipped from Hawaii now), tests could begin as early as January, tapping the expertise of West Virginia University's mobile emissions lab team. Initial test phase would evaluate using an ultra-low sulfur diesel (BP's "ECD" ULSD) to fuel four DDC 12v92 (1,050 brake horsepower) diesel engines.
The ULSD would reduce PM and sulfur oxides (SOx) emissions, while intake air water injection would be applied for NOx reduction.
# MARAD's "five-year program plan" through fiscal 2005 aims to aid evaluations of PM filters, water injection systems, selective catalytic reduction (SCR), and "clean" fuels including ULSD, FischerTropsch synthetic diesel, biodiesel, hydrogen, LNG/CNG, and fuel cells.
So far, the agency's literature search of various NOx-reduction technologies indicates that marine SCR could deliver the most NOx reduction, but at the highest capital cost.
SCR is nearly three times the cost of a water-fuel emulsion technology that delivers about half (40%) the NOx reduction of SCR. Still, new ferries planned to be built for Vallejo-to-San-Francisco service would include SCR as original equipment, as MARAD official Dan Gore told us.
As Gore explained at the U.S. Dept. of Energy's "Diesel Engine Emissions Reduction" (DEER) workshop this year, side-by-side testing of diesel and compressed natural gas (CNG) ferries in Norfolk, Va., showed that CNG actually had higher NOx emissions at full speed than the diesel ferry, with high CNG conversion capital costs, plus high gas-refueling infrastructure costs.
This test again shows that CNG cannot automatically be assumed to have lower NOx emissions despite engine NOx certification data--a finding that's turning up with increasing frequency from various CNG/clean-diesel fleet test comparisons around the world.
# Another program that MARAD evaluated--a San Francisco Bay Ferry test with biodiesel--showed a 10% NOx increase with 20% biodiesel, while 100% biodiesel caused a 24% NOx increase but a 50% PM decrease. Combined with intake air humidification, NOx was cut 12%. Biodiesel fuel cost penalty was 40 cents/gallon compared to low-sulfur diesel.
# MARAD-supported studies include an evaluation of the net emissions reduction achievable for some fast-ferry concepts, such as those proposed for San Francisco Bay. So far, studies indicate it's not clear if high-speed ferries always will deliver net emissions reductions, since many or most passengers would drive their cars to the ferries (causing car emissions), and since high-speed ferries tend to produce more emissions than low-speed ferries. Another problem: Ferries often operate only at 50% capacity.
# "Planned studies" (currently involving discussions with BP Marine, WVU and South Coast Air Quality Management District-metro Los Angeles) eventually could help pave the way for cargo vessel emissions trading. Technologies such as intake air humidification, exhaust-gas recirculation, and fuel emulsions could deliver NOx reductions of about 33%.
Since NOx credits can trade at around $19,000/ton in the SCAQMD area, it's possible to imagine that vessel operators could generate hundreds of thousands of dollars in NOx credits and thus offset the costs of NOx reduction installations. New rules and monitoring requirements would be needed in order to ensure that the NOx credits generated are actually delivering NOx benefits in the areas that need such reductions, Gore explained.
# NAVSEA (U.S. Navy) kicks off a major test program next month with five diesel fuels and six emissions reduction technologies, including one iron-based fuel-borne catalyst (FBC) additive. Test program partners include MARAD, SCAQMD, U.S. EPA, U.S. Department of Energy and California Air Resources Board.
According to NAVSEA researcher Jonathan DeHart, this program will evaluate emissions and performance via tests on a reconditioned, 400 shaft-horsepower DDC 12V-71 two-stroke, naturally-aspirated engine, a "very common" engine for Navy small boats, service craft and some ferries.
This test will include typical F-76 fuel (about 0.6% sulfur average), typical JP-5 military aviation fuel (about 0.05% sulfur), a zero-sulfur, synthetic Fischer-Tropsch diesel (possibly sourced from Sasol), a commercial ULSD fuel, and a soy-based biodiesel fuel.
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