Experimental Investigation on Microfluidic Reactive Extraction of Citric Acid Using Trioctylamine/1-Decanol System in Uniform and Nonuniform Circular Microchannels

Dilute citric acid solutions were extracted with trioctylamine (TOA) in 1-decanol at ambient conditions using indigenous microfluidic setup with 0.8 mm section diameter. In these slug/segmented flow reactive extraction processes with equal flow ratios, the channel lengths were varied from 10 to 40 cm, and the flow rates used were in a spread of 10 to 60 mL/h. The extraction characteristics were analyzed in terms distribution coefficient, extraction percentage, and change in concentration of the aqueous phase. The results were compared with the literature data of conventional reactive extraction and found that the microfluidic system was performing well on the basis of residence time. Effort had also been made to present indicative results of the system performance in a nonuniform microfluidic channel provided with a number of intermittent 1.6 mm diameter expansions. It had been found that the flow in nonuniform channels can deliver higher efficiencies and distribution coefficients.