| Summary: | 碩士 === 淡江大學 === 化學工程與材料工程學系 === 92 === In view of the high cost and gradually strict environmental protection demands for nitric oxides air pollutants, absorption by water or nitric acid aqueous solutions containing oxidative additives using hollow-fiber membrane modules might be a feasible measures. Through mathematical simulation and experiments, the feasibility and characteristics of the system are investigated in this thesis. Based on basic principles, mass transfers with chemical reactions of gas phase, membrane phase and liquid phase are modeled for a system where the additive is hydrogen peroxide. An isothermal system using a hydrophobic polypropylene hollow-fiber membrane module is set up for studying the effects of system parameters experimentally. For the waste gas with nitric oxides of 1,200ppm with a 50% oxidation ratio, the nitric oxides absorption efficiency is about 70%. Experimental results are used to determine the effective mass transfer coefficients for those nitric oxides compounds involving chemical absorption. For power plant flue gases, due to the low oxidation ratio, which is about 10%, the absorption efficiency is only about 20% even though high membrane area is used. For nitric oxides gas absorption, the advantage of membrane system lies mainly on the reduction of equipment size. To raise the absorption efficiency relies on the increase of oxidation ratio.
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