Efficient Depolymerization of Cellulosic Paper Towel Waste Using Organic Carbonate Solvents

Abstract

Efficient depolymerization of lignocellulosic biomass is a prerequisite for sugar production and its 3 subsequent up-gradation to fuels and chemicals. Organic carbonate solvents, i.e., propylene 4 carbonate (PC), ethylene carbonate (EC), and dimethyl carbonate (DMC), which are low in toxicity and biodegradable, were investigated as 'green' co-solvents (PC/H 2 O, EC/H 2 O, 6 DMC/H 2 O, solvent ratio 1:1) for depolymerization of cellulosic paper towel waste. PC/H 2 O and 7 EC/H 2 O enhanced the depolymerization of paper towel waste and improved the total sugar yield 8 (up to ~25 Cmol%) compared to H 2 O only (up to ~11 Cmol%) at mild reaction conditions (130°C, 9 20 min). The higher performance of PC/H 2 O and EC/H 2 O can be attributed to higher availability 10 of reactive protons in the catalytic system that facilitates efficient acid hydrolysis of recalcitrant 11 cellulosic fibers. Moreover, a substantial build-up of in-vessel pressure by CO 2 release during the 12 microwave-assisted reaction because of decomposition of PC or EC might have accelerated the 13 conversion of paper towel wastes. PC and EC are prospective solvents for lignocellulosic biomass 14 conversion considering their green features and notable catalytic performance, which have a good 15 potential for substituting conventional organic solvents such as dimethylsulfoxide (DMSO) and 16 tetrahydrofuran (THF) that are often considered hazardous in terms of health, safety, and 17 environmental implications.

Hydrophobic Copper Catalysts Derived from Copper Phyllosilicates in the Hydrogenation of Levulinic Acid to γ-Valerolactone

“…17,18 Levulinic acid (LA) is a sugar-based platform molecule, which can be derived from lignocellulosic resources and municipal solid waste. 19 Hydrogenation of LA to generate γ-valerolactone (GVL) is a key biorefining process because GVL is a valuable chemical. GVL has been widely used as solvents, fuel additives, and polymer precursors.…”

Sustainable valorisation of renewables through dialkyl carbonates and isopropenyl esters

“…Using PC/H2O and EC/H2O 1:1 V/V mixtures, depolymerization of paper towel waste occurred under mild conditions (T = 130 °C, t = 20 min) with an improved total sugar yield (up to ∼25 mol % of glucose) compared to H2O only (up to ∼11 mol % of glucose).The improved activity and selectivity were attributed to higher availability of reactive protons in the catalytic system, facilitating efficient acid hydrolysis of recalcitrant cellulosic fibres combined with their stability in tandem hydrolysis/dehydration process. 164…”

Modification of Cellulose Ether with Organic Carbonate for Enhanced Thermal and Rheological Properties: Characterization and Analysis

“…Propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), and dimethyl carbonate (DMC) are nonpolymeric cyclic and acyclic organic carbonate solvents that are minimally toxic and biodegradable . These solvents have been investigated as green cosolvents for modification and are considered viable alternatives to conventional ionic liquids regarding safety and environmental impact . These environmentally friendly properties of organic carbonates make them highly suitable as potential green solvents and transesterification agents for modification.…”