SIPS 2018

DETAILLED PROGRAM OVERVIEW

Ionic Liquid Based Artificial Cellulase Type Catalysts for Cellulosic Ethanol Process
Ananda Amarasekara¹;
¹PRAIRIE VIEW A&M UNIVERSITY, Prairie View, United States;
PAPER: 50/AdvancedMaterials/Regular (Oral)
SCHEDULED: 14:25/Wed./Guaratiba (60/2nd)

ABSTRACT:
Efficient hydrolysis of lignocellulosic biomass to fermentable sugars is a challenging step and the primary obstacle for the large scale production of cellulosic ethanol. Ionic liquids are well known for their ability to dissolve cellulose and our interest in the search for efficient catalytic methods for saccharification of polysaccharides has led us to develop -SO3H functionalized Brönsted acidic ionic liquids (BAILs) as solvents as well as catalysts [1]. Later we found that these sulfuric acid derivatives can be used as catalysts in water as well. For example, BAIL 1-(1-propylsulfonic)-3-methylimidazolium chloride aqueous solution was shown to be a better catalyst than H2SO4 of the same [H+] for the degradation of cellulose [2]. This observation is an important lead for the development of a BAIL based cellulase mimic type catalyst for depolymerization of cellulose [3]. In an attempt to develop a recyclable, simple enzyme mimic type catalysts we have studied quantitative structure activity relationships (QSAR) of BAIL catalysts and found that activity decreases as: imidazolium > pyridinium > triethanol ammonium [4]. Furthermore, we have investigated the effects of selected metal ions on BAIL catalyzed hydrolysis of cellulose in water at 140-170 °C. The total reducing sugar (TRS) yields produced during the hydrolysis of cellulose (DP ~ 450) in aq. BAIL solution at 140 - 170 °C using Cr3+, Mn2+, Fe3+, Co2+ Ni2+, Cu2+, Zn2+, and La3+ chlorides as co-catalysts. The highest catalytic effect enhancement is observed with Mn2+ and produced TRS yields of 59.1, 78.4, 91.8, and 91.9 % at 140, 150, 160, and 170 °C respectively; whereas cellulose hydrolyzed without Mn2+ produced TRS yields of 9.8, 16.5, 28.0, and 28.7 % at the same four temperatures. This paper will present the development of BAIL based artificial cellulase type catalysts, QSAR, catalyst immobilizations, biomass applications (corn stover, switchgrass, poplar) and recycling studies.

References:
[1] A.S. Amarasekara et al., Ind. Eng. Chem. Res., 2009, 48(22), 10152.
[2] A.S. Amarasekara et al., Ind. Eng. Chem. Res., 2011, 50(21), 12276.
[3] A.S. Amarasekara et al., Cat. Sci. Technol., 2016, 6, 426.
[4] A.S. Amarasekara et al., Sustain. Energ., 2014, 2(3), 102.