화학공학소재연구정보센터
Chemical Engineering Journal, Vol.200, 81-90, 2012
Styrene absorption in water/silicone oil mixtures
The absorption of styrene in water/silicone oil systems at a constant flow rate for emulsion compositions ranging from 0% to 20% was investigated using a dynamic absorption method. It was found that the mass transfer for air/water/silicone oil systems is roughly double than those determined for air/water systems whatever the silicone oil percentage (phi). This result, mainly due to the high value of the partition coefficient ratio (m(R) = H-water/H-oil = 257), was in agreement with the enhancement factor models proposed in the literature. Considering the volumetric mass transfer coefficient, it was shown that change in K(L)a versus phi depended on the mass transfer model used for its determination. By using the "equivalent absorption capacity" concept developed by Dumont et al. [18] (CEJ 162 (2010) 927-934; doi:10.1016/j.cej.2010.06.045), a dramatic decrease in the K(L)a with increasing silicone oil volume fraction was observed in relation to the decrease in the value of the partition coefficient H-mix. Conversely, considering a styrene mass transfer pathway in series (gas -> water -> oil), the K(L)a values for gas/water/silicone oil systems were roughly double the K(L)a for gas/water systems and did not depend on the mixture composition. The styrene mass transfer performances were also analyzed using the modeling framework proposed by Hernandez et al. [17] (CEJ 172 (2011) 961-969; doi:10.1016/j.cej.2011.07.008). This model confirmed the ability of a water/silicone oil mixture to increase the styrene mass transfer by a factor of 2 and verified that the change in H-mix versus phi followed the trend predicted by the theory (although the H-mix values determined from this model were significantly lower than the theoretical values). (C) 2012 Elsevier B.V. All rights reserved.