Queen's University - Utility Bar

QSpace at Queen's University >
Graduate Theses, Dissertations and Projects >
Queen's Graduate Theses and Dissertations >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1974/6524

Authors: FitzPatrick, Michael

Files in This Item:

File Description SizeFormat
FitzPatrick_Michael_A_201105_MASc.pdf3.68 MBAdobe PDFView/Open
Keywords: ionic liquids
value-added products
IR spectroscopy
PLS regression
optical microscopy
rapid screening
biomass dissolution
carbon dioxide
Issue Date: 2011
Series/Report no.: Canadian theses
Abstract: In the last decade there has been increasing research interest in the value of bio-sourced materials from lignocellulosic biomass. The dissolution of cellulose by ionic liquids (ILs) has led to investigations including the dissolution of cellulose, lignin, and complete biomass samples and the in situ processing of cellulose. Rapid quantitative measurement of cellulose dissolution in ILs is difficult. In this work, Fourier transform infrared spectroscopy (FTIR) spectra of cellulose dissolved in 1-ethyl-3-methylimidazolium acetate ([emim][OAc]) were subjected to partial least squares (PLS) regression to model dissolved cellulose content. PLS regression was used due to the ease in developing predictive models with this technique in addition to linear regression being ineffectual for modeling when applied to potentially thousands of variables. Applying a normalization data treatment, before regression, generated a model that estimated cellulose content within 0.533 wt%. The methods described provided the basis for a rapid methodology to determine dissolved cellulose content. Development of rapid and facile screening techniques to determine the effectiveness of various ILs as solvents for cellulose or lignin will aid in the development of lignocellulosic based bioproducts. In this work, optical microscopy with and without the use of cross-polarized lenses, was used to monitor cellulose and lignin dissolution in two imidazolium-based and two phosphonium-based ILs as well as n,n-dimethylacetamide/lithium chloride (DMAc/LiCl), demonstrating that this technique could be applied more broadly than solely for ILs. The described optical microscopy methodology was more rapid and sensitive than more traditional techniques, such as visual inspection. The viscosity of [emim][OAc] (162 cP) is 100 times that of water at 20°C and could inhibit its use as a solvent for cellulose. There is a need for simple, low-cost and environmentally benign methods to reduce the viscosity of ILs to aid in cellulose dissolution. In this work, 4 wt% cellulose dissolved in [emim][OAc] was subjected to 50 psi CO2 and 20 psi N2, as a control environment, at both 50°C and 75°C. After 24 hours a nearly 2-fold increase in dissolved cellulose over the N2 control was demonstrated through the application of a 50 psi CO2 environment for cellulose dissolution in [emim][OAc] at 50°C.
Description: Thesis (Master, Chemical Engineering) -- Queen's University, 2011-05-25 22:58:17.744
URI: http://hdl.handle.net/1974/6524
Appears in Collections:Queen's Graduate Theses and Dissertations
Department of Chemical Engineering Graduate Theses

Items in QSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


  DSpace Software Copyright © 2002-2008  The DSpace Foundation - TOP