Solubility and hydrolysis of HCFC‐22 (CHF2Cl): Upward revision of rate constants for aqueous reactions of CHF2Cl with OH− at elevated temperature |
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| Authors: | Shuzo Kutsuna Hisao Hori Makoto Naganuma Akio Shimono |
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| Institution: | 1. National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba West, 16‐1 Onogawa, Tsukuba, Ibaraki 305‐8569, Japan;2. Department of Chemistry, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka, Kanagawa 259‐1293, Japan;3. Sanyu Plant Service Co., Ltd., 1‐8‐21 Hashimotodai, Midori‐ku, Sagamihara, Kanagawa 252‐0132, Japan;4. Shoreline Science Research, Inc., 3‐12‐7 Owadamachi, Hachioji, Tokyo 192‐0045, Japan |
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| Abstract: | Henry's law constants of CHF2Cl in water at temperature T in K, KH(T) in M atm?1, were determined to be ln(KH(T))=?(11.1±1.5)+((2290±500)/T) at 313–363 K by means of a phase ratio variation headspace method. The temperature‐dependent rate constants for aqueous reactions of CHF2Cl with OH?, k (T) in M?1 s?1, were also determined to be 3.7×1013exp(?(11, 200/T)) at 313–353 K, by considering the gas–water equilibrium, the aqueous reaction at room temperature, and liquid‐phase diffusion control. The liquid‐phase diffusion control was approximated with a one‐dimensional diffusion first‐order irreversible chemical reaction model. The k (T) value we determined is 10 times (at 353 K) or 3 times (at 313 K) as large as the value reported (R. C. Downing, Fluorocarbon Refrigerants Handbook, Prentice Hall: Englewood Cliffs, NJ, 1988). This upward revision of k (T) indicates that the removal efficiency of CHF2Cl directly through the hydrolysis (CHF2Cl + OH?) is higher than previously expected at temperatures, such as 353 K, relevant to wet flue gas cleaning systems for ozone‐destruction substance‐destruction facilities. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 639–647, 2011 |
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