Total joins N. America emulsions biz; ASTM emulsions task force moving

Diesel Fuel News, Sept 16, 2002 by Jack Peckham

Chicago - TotalFinaElfs pioneering "Aquazole" diesel-water emulsion (see Diesel Fuel News 1/21/98, pl), previously restricted to Europe, now aims to join the North American emulsions market via licensees, the company announced last week.

California Air Resources Board (CARB) just verified "Aquazole" for reducing nitrogen oxides (NOx) by 16% and TotalFinaElf also claims a 60% reduction in particulate matter (PM). That's similar to the CARP-verified "PuriNOx" emulsion by Lubrizol, which achieves a 14% NOx reduction and 63% PM reduction, CARB found.

Both fuels are similar in diesel/water ratio at about 6/1, explains Alex Spataru, Adept Group, TotalFinaElf s "Aquazole" development/engineering contractor for North America.

Adept Group is seeking fleet demonstration projects as well as candidate refiners or fuel wholesalers to become "Aquazole" licensees, Spataru told us.

"We know there are a couple of other [emulsions] competitors being tested for CARB verification, so competitive pressures will cause [emulsion] price to drop" in future, he predicted. "Aquazole" also aims to achieve U.S. EPA "Environmental Technology Verification" (ETV) approval as well in order to expand its North American markets.

Fleets using emulsions potentially could earn lucrative NOx emissions credits for trading with other industries, under some emissions-trading proposals (see Diesel Fuel News 8/5/02, p9). California currently offers some emulsion financial incentives for certain high-ozone areas, and a provision in the pending U.S. House energy bill (now in House-Senate conference) would eliminate federal excise tax on the water portion of emulsions.

* ASTM Group Drafting Specifications

Meantime, an American Society for Testing & Materials (ASTM) emulsions task force (see Diesel Fuel News 6/24/02, plo) last week began drafting its first proposed specification for "emulsified diesel fuel oil." The term is a mouthful, so maybe it should earn a nickname such as "em-diesel" or "ed-diesel" to distinguish itself from ethanol-diesel "e-diesel" blends.

While ethanol "e-diesel" proponents earlier suggested they might want to become part of a new "emulsion fuel" ASTM specification, nobody representing "e-diesel" showed up at the task force meeting in Chicago last week.

While it's uncertain how or whether ethanol "e-diesel" might fit into an emulsified diesel definition, the current ASTM task group seems to be heading on a separate course.

The first draft, agreed-to by more than a dozen proponents here, defines "emulsified diesel fuel" as a combination of at least 5% water in either No. 1 or No. 2 diesel fuels (ASTM D975) or blends of No.1/No.2 diesels. Such a high water content would compromise ethanoldiesel blends, possibly causing phase separation.

These emulsified fuels must be "suitable for use in various types of diesel engines," hence the specification wouldn't include burner fuels.

This new definition also aims to exclude "free water" -- visible as a separate phase from a diesel fuel emulsion. But an ASTM test method hasn't yet been identified.

The group here agreed to maintain ASTM's flash point limit for No. 1 diesel (38[degrees]C). likely impossible for ethanol "e-diesel" to meet. Even some winterized diesel emulsions -- with hefty amounts of methanol anti-freeze -- might have a tough time meeting such a specification, unless the manufacturer changes its winter formulation.

Kinematic viscosity limits are tentatively proposed at 1.9 mm2 sec-1 (minimum) and 7.0 (maximum), based upon reports from European emulsion experience (from Italian emulsions marketer, CamTec). However, engine companies traditionally have a lower limit (4.1), the World Wide Fuels Charter specifies a 4.5 limit, and new fuel systems can depend upon fuel viscosity as part of a timing circuit. On the other hand, microemulsions of CARE diesel with up to 15% water would exceed 5.0. So it's fuzzy whether the 7.0 maximum will stand, or whether some compromise limit might emerge.

The new specification would cover both ordinary and low-sulfur diesel fuels, so it would impose a 0.048% limit on today's 500-ppm sulfur fuel (assuming 20% water content). (Cont. p3)

Likewise, a 20% water blend in high-sulfur fuel would result in a 0.48% sulfur limit for high-sulfur "em-diesel."

The draft proposed specification also would include a steel corrosion limit (D665 modified) as well as a copper strip corrosion test, in order to protect fuel-handling equipment.

Cetane number would have to match ASTM D975 standards, likely triggering cetane improver additization. Cetane index can't be determined with emulsions, but the proposed "IQT" cetane method under development might be added as a footnote.

Aromaticity potentially might be determined by the so-called FIA method, but more research will be required to see if this is appropriate.

Cloud point can't be used since "macroemulsions" turn diesel milky-white. Cold-filter plug point (CFPP) is related to cloud, so a new formula and new research on correlation to equipment in field would be required. The same need for more study would be needed for low-temperature flow test (LTFT), so the task group is seeking advice from one of the world's top diesel cold-flow experts, John Chandler (Infineum).