Dissolution of lignocellulose in ionic liquids and its recovery by nanofiltration membrane

The dissolution kinetics of lignocellulose from a suitable source of north east India has been studied in ionic liquid at room temperature. The measured profiles of time versus concentration of lignocelluloses were interpreted from a kinetic model and the rate constant was obtained by regression analysis of the data and the values of the rate constant was found to be 54.79 x 10(-8) cm/s. The dissolution profiles indicate clear prospect of separating the constituents by suitable methods. Recovery of ionic liquid has also been studied by membrane technology using commercial nanofiltration membrane. The effect of applied pressure gradient (Delta P) and concentration of lignocellulose on the rejection and membrane fouling was studied over a range of pressure and concentration of 2-5 bar and 0.01-0.03 mmole L-1 respectively. The solution flux increases with pressure in the pressure range studied indicate the effect of concentration polarization is not significant in this range. The permeation phenomenon has been analyzed on the basis of pore flow transport model and is well fitted with the experimental values. (C) 2012 Elsevier B.V. All rights reserved.