Lactic acid is an important commercial product and has been widely used for manufacturing biodegradable polymer. Current method of lactic acid isolation from fermentation broths is energy intensive and leads to the formation of large amounts of salts. Reactive liquid-liquid extraction has been reported as an alternative to isolate lactic acid. In our work, reactive extraction of lactic acid from aqueous phase using tri-n-octylamine (TOA) in n-octanol has been investigated in capillary microreactors operated under the slug flow regime. A typical microreactor setup consists of a Y-inlet junction for the generation of aqueous droplets and organic slugs, a PTFE capillary microreactor with adjustable tube lengths (with diameter of 0.8 mm) for extraction under slug flow, and a Y-splitter at the exit for the separation of the organic and aqueous phases based on the wettability difference. The experiments were performed at a 1 to 1 flow ratio of the aqueous to organic phase, with total flow rates ranging from 5 to 25 ml/h and 15% (V/V) TOA in n-octanol as the organic phase. Complexation of lactic acid and TOA combined with slug flow operation were found to enhance mass transfer rate significantly. The extraction of lactic acid (intake: 0.11 and 0.055 M) reached equilibrium after a residence time of about 1.5 minutes without a noticeable emulsion formation. The extraction efficiency appeared to be only a function of the residence time. The physical extraction behavior of the microreactor system under slug flow operation was further studied using a model system for the extraction of acetanilide from water to n-octanol. A simple model according to the penetration theory was developed for the overall volumetric mass transfer coefficient in physical extraction. The experimental results on the reactive extraction of lactic acid can be well described by this mass transfer model combined with an instantaneous reaction assumption.
|Status||Published - 27-sep-2015|
|Evenement||10th European Congress of Chemical Engineering - ACROPOLIS CONVENTION CENTER, Nice, France|
Duur: 27-sep-2015 → 1-okt-2015
|Conference||10th European Congress of Chemical Engineering|
|Periode||27/09/2015 → 01/10/2015|