Influence of by-product salts and Na2CO3 contents on gas–liquid mass transfer process in wet desulfurization of water gas
| Autor: | Cun-lu Chu, Jin-cai Yue, Shi-qing Zheng, Wen Zhang |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Mass transfer coefficient
Economics and Econometrics Environmental Engineering Chemistry Water gas 02 engineering and technology Buffer solution Management Monitoring Policy and Law 021001 nanoscience & nanotechnology General Business Management and Accounting Flue-gas desulfurization Surface tension chemistry.chemical_compound Reaction rate constant 020401 chemical engineering Chemical engineering Mass transfer Environmental Chemistry 0204 chemical engineering Absorption (chemistry) 0210 nano-technology |
| Zdroj: | Clean Technologies and Environmental Policy. 20:1367-1375 |
| ISSN: | 1618-9558 1618-954X |
| DOI: | 10.1007/s10098-018-1541-3 |
| Popis: | Among the different methods of H2S removal, the wet desulfurization is widely used because of its unique advantages. Wet desulfurization usually employs alkaline Na2CO3–NaHCO3 buffer solution as desulfurization agent, which can react with H2S in absorber tower to produce HS−. Then, HS− is oxidized into sulfur in the presence of a catalyst such as phthalocyanine dicaryon sulfonates or other desulfurization catalysts. But unfortunately, Na2S2O3, Na2SO3, NaSCN and other by-product salts are inevitably generated in the oxidation process. However, the desulfurization pH and the physical properties of the solution such as surface tension, density and viscosity are notably affected by the content in Na2CO3 and by-product salts. Therefore, it is necessary to investigate the influence of by-product salts and Na2CO3 on desulfurization efficiency. In this work, the effect of different by-product salts and Na2CO3 content on the total volumetric mass transfer coefficient KGa of H2S absorption process is experimentally explored. The results revealed that the increase in the by-product salts content results in a decrease in KGa and pH values. On the contrary, with the increase in Na2CO3 content, KGa and pH values increased. A mathematical model of the absorption process is proposed and analyzed; the mass transfer coefficient in gas phase kG and in liquid phase kL as well as secondary reaction constant k2 is calculated. The results showed that KGa was changed mainly by k2 which reflects the effect of pH. The surface tension, density and viscosity had relatively small effect on KGa. The present results provide the required theoretical guidance for practical industrial applications. |
| Databáze: | OpenAIRE |
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