Ethanol vehicle cold start improvement when using a hydrogen supplemented E85 fuel

Ethanol vehicles present a significant cold starting problem. Below 11/spl deg/C, ethanol will not form a rich enough fuel vapor-air mixture to support combustion. The addition of 15% gasoline helps to alleviate this problem, by allowing the vehicle to start primarily on the vaporized gasoline compounds. This approach does not completely eliminate the problem while substantially worsening cold start emissions. Supplementing E85 (85% ethanol, 15% gasoline) with hydrogen improves cold starting significantly. An effort was made to determine the minimum amount of hydrogen which could be used to supplement E85 and which would suffice in providing acceptable cold start performance. This was accomplished by experimental injection of pure hydrogen into the intake stream of a dedicated E85 fuelled vehicle. The minimum acceptable level of hydrogen was found to be 8% by volume at cold start conditions of -4/spl deg/C (25/spl deg/F). Initial work on an E85 hydrogen reformation technologies is also reported.