Search Results

The production of hydrogen and carbon monoxide by decomposing methanol in a self-igniting oxidation catalyst was briefly investigated as a possible cold starting method for methanol-fueled vehicles. A theoretical analysis of the two most likely reactions of oxidation-plus-dissociation and oxidation-plus-reformation indicate that both paths are limited to a production of two moles of hydrogen per mole of methanol oxidized. The energy released from the methanol oxidation appears to be sufficient to achieve this limit. Hydrogen yields of 15 to 26 volume percent were observed from a test reactor. Up to an equivalence ratio near three, the observed decomposition products compared favorably with the theoretical curves. An engine was started on the decomposition products.

Proof-of-concept testing was conducted to evaluate the ability to identify serious losses in catalyst efficiency with a dual oxygen sensor method. The dual oxygen sensor method involves a comparison between the signal from a pre-catalyst oxygen sensor to that from a post-catalyst sensor. Testing was conducted on a dynamometer test stand in an open-loop mode under steady-state conditions. Four matched catalysts and two deteriorated in-use catalysts were tested. The matched catalysts were identical in all physical characteristics, but with varying efficiencies. The operating air-fuel ratio was dynamically varied, and the test matrix included amplitude variations of the air-fuel ratio from 0.5% to 7% above and below the stoichiometric point, oscillating at three frequencies. Results from this proof-of-concept testing show measurable differences in the pre- and post-oxygen sensor signals between catalysts with good and poor conversion efficiencies.