Page 140 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

135

The values of CGUA and Camtk can be obtained from Com and COM multiplying
them by the expression:

Z= {(Pa/Pa) [273.16/(273.16 +t)]}/22.4, (60)

where Pa is the atmospheric pressure in bar; Po- normal atmospheric pressure at
sea level, in bar; 273.16 normal temperature in K; t- temperature at which the
gas analyses are carried out in °C; 22.4- the volume of 1 mol under normal
3
conditions, m /mol.
The value of AC mt can be calculated by the equation:

= AC m,Z, (61)

where AC m = fCoorQW^fQa/CWI is the average logarithmic concentration
3
3
difference of CO2 in the gas phase, m /m .
3. Because the absorption process is controlled by a first order chemical
reaction, occurring in the liquid phase, the value of Go can be presented also by
the equation:

G G = fir.a e H.F. AQ., (62)

2 3
where a e is the effective surface area of the packing in m /m and AQ is the
3
average concentration difference of CO2 in the liquid phase in kmol/m at
equilibrium with the CO2 concentration in the gas phase, not taking into account
the chemical reaction with NaOH.
4. According to Henry's law:

Pp=K HeCL, (63)

where P p is the partial pressure of the absorbed component in bars and K He is the
3
Henry constant in bar/(kmol/m ). Dividing both sides of equation (63) by the
atmosphere pressure Pa, the following equation can be obtained:

C m=(P/PJ= Kned/Pa (64)
or

(65)