Experimental evaluation and modeling of the hydrodynamics in structured packing operated with viscous waste oils

Abstract

 Hydrodynamics of two waste oils and PDMS in a structured packing was investigated  Pressure drop in the loading zone was lower than 450 Pa m-1  Loading and flooding velocities were relatively low, especially using the viscous lubricant  Billet-Schultes correlations were efficient to predict the loading and flooding points and the pressure drop  Scale-up calculations proved that transformer oil can be used in an industrial scale packed column

A mathematical model for VOCs removal in a treatment process coupling absorption and biodegradation

“…A different order of priority can also appears in mixture, with the consumption of one substrate preferred to another by the microorganisms [48]. Selection of the more adapted NAPL can therefore be conducted, by assessing the absorption performances toward the VOCs mixture [49] and also by evaluating the regeneration of the NAPL by the microorganisms [50] to recover the optimal treatment efficiencies [51].…”

Volatile organic compounds absorption in a structured packing fed with waste oils: Experimental and modeling assessments

“…The experimental set-up, whose the main elements are the packed column operated at counter-current, a fan to feed the column with air at the bottom and a centrifugal pump to feed the fresh scrubbing liquid at the top of the column, has been already described by Lhuissier et al (Lhuissier et al, 2020). The packed column (internal column diameter D col = 0.12 m and height Z = 1 m) was filled with a Flexipac® 500Z HC structured packing.…”

“…However, NAPL have typically viscosities from one to three orders of magnitude higher than water, making difficult to use co-current gas-liquid contactors and implying to select a counter-current packed column. Indeed, even if the higher viscosity of such solvents induces a higher mass transfer resistance in the liquid phase, liquids having viscosities up to two orders of magnitude higher than water can be successfully implemented in packed column according to several studies (Billet and Schultes, 1999, 1993a, 1991Brunazzi et al, 2002;Lhuissier et al, 2020;Minne et al, 2018;Song et al, 2018Song et al, , 2014.…”

“…These studies confirmed the potential of NAPL for VOC absorption but did not allow to determine the values of the local mass transfer coefficients (k L and k G ) and of the interfacial area (a°), which would allow to quantify accurately the influence of the solvents' characteristics (particularly the viscosity). In a previous paper, Lhuissier et al (Lhuissier et al, 2020) studied the hydrodynamics of lubricant and transformer waste oils in a lab-scale packed column of 0.12 m of internal diameter filled with a Flexipac® structured packing (packing height of 1 m). Their results showed that it was possible to operate countercurrent packed column with viscous waste oils, especially the transformer oil.…”

“…Nonetheless, no experimental study dealing with VOC absorption in waste oils in a packed column has been reported yet. Thus, the main purpose of this study was to assess the potential of lubricant and transformer oils for VOC absorption in the same packed column used by Lhuissier et al (Lhuissier et al, 2020), in comparison to water and a synthetic silicone oil. Seven VOCs of different natures and with various polarities (n-heptane, ethyl acetate, propan-2-ol, methylisobutylketone (MIBK), toluene, m-xylene and 1,3,5-trimethylbenzene (TMB), whose the octanol-water partition coefficients are summarized Table A.1 in Appendix) were selected (Lhuissier et al, 2018).…”