| Summary: | 碩士 === 元智大學 === 化學工程與材料科學學系 === 104 === The burning of fossil fuels has led to climate change due to global warming or the greenhouse gas effect. Carbon dioxide (CO2) has become the biggest source with six billion tons of carbon released as CO2 every year. A highly selective catalyst for methanol formation and carbon dioxide conversion desired to reduce CO2 emissions as well as offer an alternative fuel source and chemical feedstock. Methanol synthesis was conducted using copper-based catalyst (Cu/ZnO/Al2O3) with co-precipitation method in a fixed bed reactor.
The experimental conditions including mole ratio of hydrogen to carbon dioxide, gas hourly space velocity, precipitation temperature of co-precipitation, reaction temperature were studied to obtain the optimal condition for methanol synthesis. Meanwhile, a lower precipitation for preparing the catalyst temperature is propitious to get a higher Cu dispersion, a smaller Cu crystal size, and a higher activity for methanol synthesis. The best space time yield (STY) obtained was 9.33 g/kg-cat/h. Cu/ZnO/Al2O3 (45/45/10 mol%) catalyst at the reaction temperature was 200 oC, CO2 conversion equaled to 13 % and methanol yield equal to 2.7% and the best space time yield (STY) was obtained 9.33 g/kg-cat/h at 7 bar. In addition, the weight composition of copper base catalyst influenced the activity according to the analytical result using surface methodology.
Characterization of the catalyst was carried out with ASAP (Accelerated Surface Area and Porosimetry), XRD (X-ray diffractometer), TPR (Temperature program reduction), and SEM (scanning electron microscope) as well.
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