Chemical Engineering Communications, Vol.200, No.5, 678-700, 2013
INTENSIFICATION OF RECOVERY OF FORMIC ACID FROM AQUEOUS STREAM USING REACTIVE EXTRACTION WITH N, N-DIOCTYLOCTAN-1-AMINE: EFFECT OF DILUENT AND TEMPERATURE
The present work is aimed at intensifying the recovery of formic acid from aqueous solution (industrial waste stream, bio-oil generated stream, and fermentation broth) using reactive extraction. Six different diluents (decane, benzene, decan-1-ol, decane (w=0.725) +decan-1-ol (w=0.275), MIBK, and chloroform) with and without N, N-dioctyloctan-1-amine (TOA, as an extractant) were used. The maximum extraction efficiency, KD,max, is found to be 29.11 with TOA in chloroform at 298K. Differential evolution optimization technique was employed to estimate stoichiometry of reaction (m and n), overall (KE), and individual (K11, K21, K31, and K12) equilibrium constants through a proposed mathematical model. The effect of diluent on KD was quantified by the LSER model using solvatochromic parameters of diluent. The effect of temperature (298 to 343K) on KD was also studied. The values of H and S of reactive extraction were calculated as 96.64kJ center dot mol1 and 263.583J center dot mol1 center dot K1, respectively.
Keywords:Aqueous stream;Differential evolution;Diluents;Process intensification;Reactive extraction;Temperature