Oxidation of alcohols is an important process in chemical industry, and the high demand for green chemistry has driven researchers to employ molecular oxygen rather than traditional, toxic chemical oxidants.1
However, the solubility of oxygen in the substrate could potentially limit the extent of the reaction. Hence, data on the solubility of oxygen under reaction pressures and temperatures is essential information for reactor design and process optimization.
In this study, a novel method using a Teflon AF-2400 tube-in-tube membrane contactor is proposed for the measurement of oxygen solubility. The semi-permeable membrane contactor allows the liquid substance to be saturated with oxygen at specific temperatures and pressures. When the pressure reduces to atmospheric pressure, the volumetric flow rate of oxygen released can be accurately measured and used for the solubility calculation. This method was initially employed to investigate the oxygen solubility in toluene, and the results agreed well with the literature2,3
(where the data were obtained with traditional equilibrium apparatus). The solubility of oxygen in benzyl alcohol was then experimentally measured with pressures up to 1.0 MPa at temperatures from 293K to 393 K. An empirical equation of the Henryâ??s law constants as a function of temperature was also determined.
1. Davis SE, Ide MS, Davis RJ. Selective Oxidation of Alcohols and Aldehydes over Supported Metal Nanoparticles. Green Chem. 2013;15(1):17-45.
2. Wu X, Deng Z, Yan J, Zhang Z, Zhang F, Zhang Z. Experimental Investigation on the Solubility of Oxygen in Toluene and Acetic Acid. Ind. Eng. Chem. Res. 2014;53(23):9932-9937.
3. Li A, Tang S, Tan P, Liu C, Liang B. Measurement and Prediction of Oxygen Solubility in Toluene at Temperatures from 298.45 K to 393.15 K and Pressures up to 1.0 MPa. J. Chem. Eng. Data. 2007;52(6):2339-2344.