Abstract:
The effects of reaction conditions on hydrogen production from methanol steam reforming were discussed. The experimental results showed that the optimal temperature of the reaction was about 240 ℃. High temperature increased the selectivity of CO, and low temperature decreased the conversion rate of CH
3OH. When the molar ratio of H
2O to CH
3OH increased, the conversion rate of CH
3OH increased and the selectivity of CO decreased. If the molar ratio of H
2O to CH
3OH was too high, more energy would be consumed. To ensure the conversion rate of CH
3OH, the liquid hourly space velocity of feed liquid was appropriately increased. The Langmuir-Hinshelwood two-rate dynamics model equation was used to fit the experimental data of intrinsic dynamics. The calculated values of molar flow rates of CO and CO
2 in the gas products at the reactor outlet were in good agreement with the experimental values, and the two-rate model was applicable. The deactivation of CuO/ZnO/Al
2O
3 modified catalysts at 200 ℃ and 300 ℃ was also investigated. Using BET, XRF, XRD and CO-TPD, it was found that the main reasons for the deactivation of the catalysts were, in addition to hot sintering, the reduction of specific surface area and mesoporous ratio, the CuO loss, and the increase of CuO grain size. The high content of CO produced in the high temperature had no obvious effect on catalyst deactivation.