Use of Vanadium(V) Oxide as a Catalyst for CO2 Hydration in Potassium Carbonate Systems

详细信息    查看全文

• 作者：Nathan Johann Nicholas ; Gabriel da Silva ; Sandra Kentish ; Geoffrey W. Stevens
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：February 26, 2014
• 年：2014
• 卷：53
• 期：8
• 页码：3029-3039
• 全文大小：554K
• 年卷期：v.53,no.8(February 26, 2014)
• ISSN：1520-5045

文摘

The kinetics of CO₂ absorption into 30% w/w K₂CO₃ solutions containing 0.1鈥?.5 M K₄V₂O₇ was investigated at temperatures of 40, 60, and 75 掳C using a wetted wall column. Vanadium(V) speciation diagrams were developed under these conditions as a function of CO₂ loading using ⁵¹V NMR spectroscopy. From these studies it was determined that there are two oxyvanadate ions that promote the absorption of CO₂, HVO₄^{2鈥?/sup>, and HV₂O₇3鈥?/sup>. The Arrhenius expressions for the rate constants of these two species were found to be k_HVO4 = 2 脳 1011 exp(鈭?992/T) and k_HV2O7 = 5 脳 1018 exp(鈭?0218/T), respectively. Comparison of the observed rate constants with other promoters revealed that both active vanadium species showed performances comparable with that of MEA and vastly superior performances over those of other inorganic promoters. Due to speciation changes as the vanadium concentration is increased, the relative performance of vanadium diminished with increasing total vanadium concentration. As such, vanadium may be more suitable as a secondary component and corrosion inhibitor in a promoted carbonate system.}