Volumetric mass transfer coefficient

tuks_123 · July 22, 2010, 01:24

My objective is to evaluate overall volumetric mass transfer coefficient, using CFD, for CO2 absorption from Air (gas) to Amine (liquid) with no reactions.

Using basic definition "N*a = K_L*a*(C_L_eq - C_L)". Where N is molar flux, K_L*a is volumetric coefficient and C_L_eq and C_L are concetration at interface (in equlibrium with gas phase conc) and bulk concentration. All values pertaining to CO2 in liquid ammonia/amine.

Can we evaluate K_L*a from hydrodynamics and concentration profiles in CFD?
My approach could be

Define diffusivity of CO2 in Air (gas) and amine (liquid).
Define gas-liquid interphase mass transfer using a model where only Henry's constant for CO2 needs to be specified.
Solve the momentum, mass transfer equations for gas, liquid phases and get concentrations pofiles.
Use concentration profiles to calculate molar flux (N) and then calculate K_L*a.

As I dont know details of interphase mass transfer models in CFX. Also I am not sure if approach is correct?
Experts views are welcome.

Thanks
Tuks

zumanzi_011 · April 2, 2021, 00:25

Hi,

I was wondering if you were able to do it. If so, could you please explain in brief the procedure of kla determination using CFD, additionally any publication to follow?

I am trying to find out absorption coefficient of methane into internal olefin.

July 22, 2010, 01:24	Volumetric mass transfer coefficient	#1
tuks_123 New Member tukaram Join Date: Jul 2010 Posts: 9 Rep Power: 15	My objective is to evaluate overall volumetric mass transfer coefficient, using CFD, for CO2 absorption from Air (gas) to Amine (liquid) with no reactions. Using basic definition "Na = K_La(C_L_eq - C_L)". Where N is molar flux, K_La is volumetric coefficient and C_L_eq and C_L are concetration at interface (in equlibrium with gas phase conc) and bulk concentration. All values pertaining to CO2 in liquid ammonia/amine. Can we evaluate K_La from hydrodynamics and concentration profiles in CFD? My approach could be Define diffusivity of CO2 in Air (gas) and amine (liquid). Define gas-liquid interphase mass transfer using a model where only Henry's constant for CO2 needs to be specified. Solve the momentum, mass transfer equations for gas, liquid phases and get concentrations pofiles. Use concentration profiles to calculate molar flux (N) and then calculate K_La. As I dont know details of interphase mass transfer models in CFX. Also I am not sure if approach is correct? Experts views are welcome. Thanks Tuks

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April 2, 2021, 00:25		#2
zumanzi_011 New Member Shahriar Mahmud Join Date: Mar 2016 Posts: 6 Rep Power: 10	Hi, I was wondering if you were able to do it. If so, could you please explain in brief the procedure of kla determination using CFD, additionally any publication to follow? I am trying to find out absorption coefficient of methane into internal olefin.