Summary: | 碩士 === 國立中央大學 === 化學工程與材料工程研究所 === 100 === Gasification system means that coal is transformed to synthesis gas (syngas), which is then converted to hydrogen and carbon dioxide via water gas shift reaction. Then, carbon dioxide is captured after the temperature of mixture gases are reduced by condenser. Pressure swing adsorption (PSA) can then be utilized to purify hydrogen to high concentration and to capture carbon dioxide. The former can generate electrical power, the latter can be recovered and stored.
This study plans to use a dual-bed PSA process with modified activated carbon AC5-KS to separate high-purity hydrogen and to capture carbon dioxide from syngas, which contains water vapor, carbon monoxide, carbon dioxide and hydrogen at room temperature. The optimal operating condition is discussed by varying the operating variables.
In this study, the optimal result of dual-bed 8-step PSA process in the first H2-PSA stage produces high-purity hydrogen of 99.59% with a recovery of 86.17%, and the carbon dioxide recovery is 99.23%. The optimal result of dual-bed 6-step PSA process in the second CO2-PSA stage generates carbon dioxide purity and recovery of 90.49% and 99.64%, respectively. The hydrogen purity is 94.82%. By two stage PSA process, the total carbon dioxide recovery from syngas is 99.23%.
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