ABSTRACT
A multi-stage continuous bubble cap foam fractionation column was developed to achieve high separation performance using cetyltrimethyl ammonium bromide (CTAB) as a model surfactant. The effect of design and operating parameters on the overall performances was investigated at a steady state. The results illustrated that with increasing the airflow rate, the enrichment ratio of CTAB was decreased and its recovery percentage increased. When the feeding concentration of CTAB was greater than 0.2 g/L, the adsorption of CTAB at the gas-liquid interface was closed to equilibrium. Based on mass balances and equilibrium relationships, a new method of the number of theoretical stages by stage-to-stage calculation and graphics were presented on the foam fractionation column.
Nomenclature
Aconductivity value, μs/cm
Csurface-active substance concentration, g/L
CFfeeding concentration, g/L
Cn nth stage CTAB concentration, g/L
CQfoamate concentration, g/L
CTABcetyl trimethyl ammonium bromide
CWeffluent concentration, g/L
effective concentration, g/L
d32average bubble diameter, m
Eenrichment ratio
Ffeeding flow rate, L/min
H0tray spacing, mm
Kadsorption constant
mnumber of bubbles
nstage number
Nfnumber of feeding stage
Ncnumber of bubble caps per tray
Nunumber of stages
Qfoamate flow rate, L/min
Qgairflow rate, mL/min
Rrecovery percentage
Sspecific surface area, m2/min
Weffluent flow rate, L/min
Greek letter
Surface excess, g/m2