Continuous Starch Liquefaction Through In-Line Static Mixer Reactor

Abstract

Hydrolysis of cassava starch using α-amylase for liquefaction step through and in-house design and construction of In-Line Static Mixer Reactor (ISMR) can save cost and process time when compared to starch hydrolysis in a stirred tank reactor. Starch at different concentrations was hydrolysed by α-amylase at 90 oC through the ISMR at different flow rates from 15 mL/min to 50 mL/min and different tube lengths up to 12.6 m. Lysis at a flow rate of 15 mL/min with the maximum tube length of 12.6 m gave superb result as this condition possessed the longest reaction residence time of 65.94 min. The concentrations of reducing sugars of 20.81 mg/m with a Dextrose Equivalent (DE) value of 18.99 and 55.46 mg/mL with a DE of 44.75 were obtained from liquefaction of starch at the concentration of 25% and 32% w/v, respectively. Viscosity of starch and sugar dextrin solution during liquefaction reduced as a function of hydrolysis distance, residence time and a low flow rate. The flow regime of starch solution was very laminar with a Reynolds number (Re) value of < 15 during liquefaction through the ISMR. This ISMR was essentially shown an excellent performance with scaleable potential for commercial production of sugar from starch hydrolysis using residence time as a key parameter.