This study investigated the effect of fuel spray droplet size on hydrogen produced by a methanol reformer. The experimental parameters included methanol supply rate, Sauter mean diameter (SMD) of methanol spray, O2/C (Oxygen/Carbon) ratio and S/C (Steam/Carbon) ratio. The investigation involved the study of cold start transient response of the reformer and the characteristics of the hydrogen production with attention paid on reducing the time taken for the reformer to commence producing hydrogen from cold start.
Partial oxidation reforming was first employed to determine the optimum cold start parameters for this system. A purpose-made twin-fluid nozzle was applied, which allowed varying of the assisting air flow rates to regulate the fuel spray droplet size with the objective of investigating the effect of the droplet size on the cold start performance of the reformer. From the experiments, it was shown that under low methanol supply rate coupled with an appropriate fuel spray droplet size, the catalyst could quickly attain its reaction temperature with a short cold start duration. In comparison, the effect of spray droplet size was less evident with high methanol supply rate from cold start. Further, it was demonstrated that the thermal management method of external heating significantly improved hydrogen yield under different S/C ratios, with the maximum yield of 89% achieved with an S/C ratio of 2.0.
The 21st International Symposium on Transport Phenomena, Taiwan