Clean Diesel Technologies, a developer of chemical and technological solutions to reduce harmful engine emissions, announced that independent tests have demonstrated that the platinum emissions from the Company’s Platinum Plus fuel borne catalyst (FBC) do not pose an allergenic risk.
Platinum Plus is a bimetallic platinum/cerium kerosene-based fuel additive used at 4–8 ppm metal in fuel that:
Improves fuel economy between 3%–8%
Reduces PM emissions by 10–20% (30%–50% when combined with an oxidizer, 95% when combined with filter)
Reduces HC and CO emissions by 10%–30% (50% when combined with an oxidizer)
Lowers filter regeneration temperature to 300º–350° C.
The engine tests used to generate samples for analysis were performed at the Southwest Research Institute (San Antonio, TX) on a typical heavy duty truck engine that had been operated for 1,000 hours at high fuel rates and elevated doses of FBC.
Independent analysis of the engine emissions was done by researchers at the University of Wisconsin, who analyzed for the trace fraction of platinum where potentially allergenic forms might be found. This work has confirmed that any potential allergenic species of platinum emitted, if present at all, would be hundreds to many thousands of times below the most conservative published reference safe exposure levels.
The emissions are also consistent with reported platinum emissions from existing heavily catalyzed devices such as auto catalysts and catalyzed diesel emission control systems typically used in vehicles on the road today.
The testing was done at the request of the U.S. Environmental Protection Agency based on the substantial growth in interest and use of the Platinum Plus FBC product to control emissions and improve fuel economy in diesel engines.
The testing techniques showed most of the platinum emission was in a form consistent with it being platinum metal and oxide, which are generally regarded as non-allergenic. The remainder, less than 1% of the platinum emitted, could be water dissolvable with some anionic character, as determined by ion exchange separations, which is the portion where any potentially allergenic forms would be found.
The University of Wisconsin analysis was conducted on emissions from a heavy duty diesel engine, emitting over 100,000 µg/hp-hr of toxic diesel particulates (PM). The FBC and ultra low-sulfur fuel reduced PM by over 20,000 µg/hp-hr while emitting less than 0.3 µg/hp-hr of water soluble and potentially anionic platinum fraction.
Used in conjunction with a lightly catalyzed diesel oxidation catalyst (DOC) or catalyzed wire mesh filter (CWMF) the Platinum Plus FBC is verified to reduce toxic PM by 40-75%, equivalent to a reduction of 45,000-75,000 µg/hp-hr of toxic soot emissions. Tests with a diesel particulate filter and FBC treated fuel showed over 95% reduction in particulates with 99 percent of the platinum retained in the engine, exhaust and filter.
Data were submitted to the EPA on a regular basis during the eight month program and a final report was submitted to the EPA in early October, 2005. Researchers from the University of Wisconsin and CDT have submitted a paper on the results of the program for presentation at the SAE World Congress in 2006.
CDT also studied reports from the literature that indicated up to 25% of the platinum in heavily catalyzed devices like auto catalysts and diesel oxidation catalysts can be emitted, of which 1%–10% was generally reported as soluble. CDT concluded that the platinum emissions rates and species appear to be similar for the FBC and current catalyzed systems in widespread use. When the FBC is used with a DPF, platinum emissions are less than the reported platinum emissions from auto catalysts.
In September, CDT signed a blending and distribution agreement with Fleetguard, Inc., a business unit of Cummins Inc. (CMI), for the sale of Platinum Plus Fuel-Borne Catalyst (FBC) in North America and international markets. (Earlier post.)
Under the terms of the agreement, Fleetguard will purchase Platinum Plus FBC concentrate from Clean Diesel for blending into finished products for sale to distributors and end users in the on-highway, off-road, marine and power generation markets.