Japan taking temporary lead on clean-diesel; new clean-fuel, reformed-lubes limits coming

Diesel Fuel News, Nov 11, 2002 by Jack Peckham

Japan claims to take over the world's leadership on heavy-duty clean-diesel regulation between now and 2005, as refiners convert to a 50-ppm sulfur limit (ultra-low sulfur diesel) and vehicle makers install diesel particulate filters (DPFs).

As a result, Japan's 2005 heavy-duty diesel vehicle emissions limits will fall to 2 grams/kilowatt hour for nitrogen oxides (NOx), and 0.027 g/kWh for particulate matter (PM), as TonenGeneral Sekiyu's Shuuzo Nemoto explained at the industry/U.S. Department of Energy "advanced petroleum based fuels-diesel emissions control" (APBF-DEC) meeting in Washington, DC, last month.

This "clean" leadership would be only temporary as U.S. EPA heavy-duty highway 2007 diesel emissions limits result in the equivalent of 0.268 g/kWh NOx and 0.0 13 g/kWh PM, if measured on Japanese test cycles. The 2007 EPA limits are about ten times tougher than Japan 2005 NOx limits, and less than half the Japan 2005 PM limit.

While DPFs are becoming mandatory for Japan (and almost certain for EPA 2007), Japan's forecast for NOx aftertreatment is fuzzy, Nemoto explains. "Although there is a government program for developing the SCR [selective catalytic reduction] technology in Japan, the main concern will be reliability and durability," he told us. "Further, to my knowledge, sufficient discussions about urea infrastructure [for SCR reductant] have not been carried out yet. Therefore, SCR would not be in time for Japan's 2005 regulation, or may be restricted to certain specialized use."

Whether a "NOx Storage & Release" (NSR) device (NOx trap) can be mated to a DPF and meet future durability and emissions requirements is likewise uncertain, although engineers are encouraged by promising developments with Toyota's "DPNR" system for light-duty, he added.

Similar to the U.S. "APBF-DEC," the joint industry/government "Japan Clean Air Program-2" (JCAP-2) aims to investigate advanced NSR systems for effectiveness, durability and compatibility with various sulfur levels in ULSD and sulfur in lube oils.

Japan's refiners, vehicle makers and government officials also are in talks about a possible conversion of 50-ppm sulfur ULSD to a 10-ppm sulfur limit (see Diesel Fuel News 1/21/02, p1). So, JCAP-2 is also investigating the impact of 10-ppm ULSD and reformulated lubes on NSR systems, as a follow-on to earlier sulfur effects studies in the now-complete "JCAP-1" program.

Petroleum Association of Japan (PAJ) recently confirmed that its member companies will supply 50-ppm ULSD virtually nationwide by next April, and "preliminary discussions were just started about the necessity of 10-ppm cap sulfur in the farther future," Nemoto told APBF-DEC meeting.

JCAP is investigating lower ash, sulfur and phosphorus limits for lubes, in part to avoid DPF ash clogging. As a result, lower-ash lube standards will be introduced by April 2005, and other limits to protect De-NOx catalysts will be investigated between now and mid-2006, he said.

More highlights from JCAP-1 and JCAP-2:

* A 10-ppm sulfur ULSD with a kerosene-like distillation can aid NOx reduction in a NSR catalyst. This is because "a low-distillation fuel can easily vaporize and create better fuelrich circumstances" for the periodic fuel-rich spikes, as JCAP investigator Toshiaki Kakegawa reported at APBF-DEC.

But any sulfur degrades NSR catalyst performance over time. So, Japan's refiners "are expected to develop technologies to further reduce fuel sulfur level concurrently with the preparation of 50-ppm fuel supply," while vehicle makers "are expected to develop technologies for after-treatments and their sulfur poisoning recovery," Kakegawa said.

For JCAP-2 (2002-2006), oil and automotive researchers will evaluate technologies to cut both pollutants and [CO.sup.2] emissions further. This test will involve six vehicles and engines with "advanced aftertreatment, combustion technologies and electronic controls," he said. These tests will employ a nine-fuels matrix of three sulfur levels (50, 10 and 1 ppm), three aromatics levels (20, 10 and 5%) and variable distillation characteristics.

JCAP-2 also will investigate nanoparticle formation, nano-PM chemical composition, atmospheric transformation of particles and vehicle/area emissions modeling.

Coincidentally, Japan's increasing focus on diesel emissions control comes just as its oil industry foresees a decline in highway diesel demand. Petroleum Association of Japan (PAJ) earlier this year forecast a decline in gasoil/diesel fuel sales because of an assumed decrease in diesel car sales (due to very strict environmental regulations).

As a result, PAJ's forecast sees Japan's gasoil demand at 38.4 billion liters in 2005, down from 41.3 billion liters last year. Yet other middle distillates are still on an upswing, as kerosene sales would rise slightly, to 31 billion liters in 2005, versus 30.4 billion liters last year. Jet fuel demand likewise would increase, to about 4.8 billion liters, from 4.6 billion liters last year. Fuel oil "A" (maximum 5,000-ppm sulfur "No.1") also will increase slightly due to industrial production growth, PAJ forecasts.