(501e) Cost-Efficient Ionic Liquid and Water Mixtures for Biomass Dissolution

The adoption of lignocellulosic feedstocks in an industrial process used to commercially produce biofuels is contingent upon cost-effectively and efficiently disrupting the lignin present, as it inhibits downstream enzymatic-hydrolysis efficiency. There are numerous reports in the scientific literature on the capability of ionic liquids (ILs) to disrupt cellulose structure and dissolve lignin effectively. Ionic liquids offer exciting prospects due to properties such as their low volatility and “tunability”.  In this study a new class of ionic liquids were designed and tested for their capacity to improve the enzymatic hydrolysis efficiency of switchgrass. The ionic liquids tested were based upon a sulphate anion, whilst varying the cation.  The number of alkyl chains on ammonium based cations were investigated. The ionic liquids were designed so that they can effectivly remove lignin and leave the cellulose intact, thereby enabling easier fractionation post pretreatment. Another benefit of this class of ionic liquids is their lack of sensitivity to H­₂O, enhancing their handling properties. A focus was also placed on designing these ionic liquids from ubiquitous low cost chemicals, with the aim of mitigating reagent cost, thereby enhancing their industrial relevance.  The metrics used to evaluate these ionic liquids were degree of lignin dissolution, effect on cellulose structure, ease of pretreated material fractionation and enzymatic hydrolysis efficiency.