Lean Burn - Hydrogen Enrichment

[GeneW]

I'm going to restart the Hydrogen gas enrichment threads here.

I'm not into beating that poor little Nippon-Denso alternator with which we're equipped. I'm hoping that a catalytic reformer of gasoline emerges on the market that we can buy.

Creating a hydrogen vapor and spraying it into the engine makes it easier to combust the incoming air-fuel mixture, greatly reducing wall wetting. "And hydrogen injection has another benefit," says Botti, "it can be utilized to heat the catalyst up much faster than normal." Delphi estimates a catalyst warm-up time of 20 seconds could be cut in half by adding this system, and allow a 50% reduction in the precious metals found in the catalyst; a significant cost reduction to the OEM. "Tighter emission standards are going to increase the load on catalysts, which normally means more precious metals are necessary," Botti says, "but we think this technology will mitigate those costs." It also should ease or eliminate the need to increase catalyst package size in order to meet the tighter standards, particularly on larger engines, and make it easier to reach SULEV (Super Ultra-Low Emission Vehicle) standards.

Delphi's hydrogen enrichment system
Schematic shows the basics of Delphi's hydrogen enrichment system, slated for production mid-decade. By reformulating a small amount of gasoline in to hydrogen gas, the unit can be used to cut catalyst light-off time in half, and increase the lean-burn tolerance of conventional internal combustion engine designs.

The on-board reformer, however, will have uses beyond start-up emission reduction. "The hydrogen uses very little gasoline, but allows a lean mixture to be used by making the engine more tolerant of lean-burn conditions," says Botti. "We are looking at putting up to 30% EGR (exhaust gas recirculation) back into the engine, which will easily compensate for the small amount of fuel we use to create the hydrogen in the first place." So, on the fly, a hydrogen enrichment-equipped vehicle could call on the unit to improve dynamic emission performance, giving automakers greater calibration flexibility. "We believe this technology will allow OEMs to run lean-burn combustion longer, and over a broader range of driving conditions," says Botti.

http://www.autofieldguide.com/articles/090203.html

Gene