Efficiency Improvement of Halogenated Gaseous Pollutants Destructed by Molten Salt

• Main Authors: Ming-Feng Wang, 王銘鋒
• Other Authors: Kuo-Ching Chang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/05952953998459566266

碩士 === 國立屏東科技大學 === 環境工程與科學系 === 90 === Industries of petrochemicals, automobile, plastics, semiconductor and processes of all kinds of painting have problems of organic pollutions. Several shortcomings were found in pollution treatment, for example, wastewater and sludge problems were produced in the process of removing high concentrated acid and toxic gases such as hydrogen chloride,hydrogen fluoride, and chloride gas in the incineration treatment of hydrocarbon compounds with halogen using a scrubber. The catalytic combustion process required the pretreatment to avoid the catalyst blocking and poisoning. Using active carbon to absorb high concentrated organic pollutants was expensive, and other problems such as temperature,regeneration facility as well as other wastes were also needed to be solved. The purpose of this research are to develop an economical, simple, and clean technology, which can attain high destruction and removal efficiency of gaseous halogenated organic pollutants and recover some resources. In this research, a variety of volatile halogenated organic compounds will be used as study materials, especially,CFC-12(diehlorodifluromethane) because of its superior chemical stability and low decomposition rate by other thermal treatment methods. Different mixtures of salts will be used as the treatment medium. Experiments will be codueted with varied operating parameters, such as concentration, temperatures, kinds of molten salt, flow rate, residence time, bubble size, and ect. Some preliminary experiments with molten mixture of sodium nitrate and sodium nitrite at 500℃ have been performed and showed that this new treatment technique is promising .Results showed DRE could be up to 70﹪when 0.15LPM of gaseous flow capacity and 90﹪of CFC-12 was fed at 500℃. The reacted gaseous products were mainly carbon dioxide and water and the organic and inorganic acid gases were not observed. The elements of chlorine,fluorine, and organic compounds were captured by the molten salt and converted to sodium chloride, sodium fluoride, and sodium carbonate.There products of inorganies salts can easily be further purified and recovered to salable grade, thus meet the green criteria for sustainable development.