| Summary: | 碩士 === 國立中興大學 === 機械工程學系所 === 104 === The objective of this study was to experimentally compare water-gas shift reaction performance using commercial available Fe-Cr catalyst and self-prepared 2.5wt%Pt-2.5wt%Ni/Al2O3. The experiments were carried out with steam to carbon (S/C) ratios of 1, 3, and 5; temperature in 400~850°C range; and pressure of 1 atm. Both sweet and sour syngases were used as the feedstock for the reaction. The measurement started from 400°C, with increment of 50°C, raised to 850°C. For each temperature, the measurement lasted for 12 hours. For each set of experiment, the time required was about 120 hours. Based on the measured data, it was found that higher CO conversion and H2 yield can be obtained from Fe-Cr catalyst when temperature is lower than 600°C as compared with those resulted from Pt-Ni catalyst. This was attributed to the reason that Pt is an inert metal at low temperatures. Reversely, higher CO conversion and H2 yield can be obtained from Pt-Ni catalyst as temperature is greater than 600°C. The experimental data also indicated that good thermal stability of both catalysts can be obtained during the 120 hours test period. With S/C=5 and syngas consisting of 2% N2, 34% H2, 17% CO2, and 47% CO, maximum CO conversion and H2 yield can be resulted from Pt-Ni catalyst at 600°C having the values of 81.82% and 53.10%, respectively.
The measured results showed that the capability of the both catalysts used was degraded with the presence of 30 ppm H2S in the syngas. The measured results indicated that more significant reduction in catalyst capability was found for Pt-Ni catalyst. For S/C=3 and 600°C case, it was found that the CO conversion H2 yield dropped from 79% and 52.5% for sweet syngas to 72.35% and 47.2% for sour syngas from Pt-Ni catalyst.
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