Catalytic Conversion of Lignocellulosic Biomass to Levulinic Acid in Ionic Liquid

Abstract

The catalytic conversion of lignocellulosic biomass to levulinic acid in ionic liquid, [EMIM][Cl] was conducted using a hybrid catalyst. The hybrid catalyst (1:1 ratio) with equal CrCl 3 and HY zeolite weight ratios was synthesized using a wet impregnation method. Initially, optimization of cellulose as a model compound was carried out using two-level full factorial design ( 2 3 ) with two centre points. Under optimum process conditions, 46.0% of levulinic acid yield was produced from cellulose. Subsequently, utilization of lignocellulosic biomass demonstrated 15.5% and 15.0% of levulinic acid yield from empty fruit bunch (EFB) and kenaf, respectively, at the optimum conditions. Meanwhile, in the presence of ionic liquid under the same process conditions, 20.0% and 17.0% of levulinic acid were obtained for EFB and kenaf, respectively. The results indicated that ionic liquid could disrupt the covalent linkages between the biomass structures and dissolved the hollocellulose. This allowed the hollocellulose chains, accessible to the chemical transformation, to react and produce levulinic acid in presence of the hybrid catalyst. This study demonstrated that the combination of hybrid catalyst and ionic liquid has the potential to be applied for biomass conversion to levulinic acid under adequate process conditions.

New Frontiers in the Catalytic Synthesis of Levulinic Acid: From Sugars to Raw and Waste Biomass as Starting Feedstock

“…Ionic liquids are salts consisting of ions which are liquid at ambient temperatures or below 100 • C [135]. The stability, the low vapor pressure, the easy separation and recyclability of ionic liquids, coupled with the fact that their physical and chemical properties can be easily tuned by varying the ions, are some of the important reasons for the intense interest for the use of these solvents to convert raw biomass into added-value products [136][137][138][139][140][141][142]. Catalytic conversion of biomass to LA in the ionic liquid [EMIM][Cl] using a hybrid catalyst (CrCl 3 and HY-zeolite) has shown to yield 46 wt % of LA from cellulose working at 61.8 • C for 14.2 min.…”

Review: Sustainable production of hydroxymethylfurfural and levulinic acid: Challenges and opportunities

“…It is rather surprising that the same attention has not been paid to LA production, to the extent that no work in this direction had been conducted till 2011 [57]. Recently, though, Ya'aini and Amin have reported the use of the ionic liquid [EMIM]Cl for LA production [266]. A hybrid CrCl 3 -HY zeolite catalyst was used, and a yield of 46 wt% was obtained from cellulose, and 20 and 17 wt% from empty fruit bunch and kenaf.…”

Conversion of Biomass and Its Derivatives to Levulinic Acid and Levulinate Esters via Ionic Liquids

“…Recent studies showed the possibly of one-pot production of LA and LE from various lignocellulosic biomasses via various catalytic methods, including wheat straw, ,, bamboo, ,, oil palm biomass such as empty fruit bunch, fronds, and kenaf, ,,,− sorghum grain, marine biomass, , bagasse, , rice husk, rice straw, switchgrass, wood chips, and paper pulp as well as paper waste . Nevertheless, the use of ILs for the one-pot production of LA and LE from various lignocellulosic biomasses is still at the developing stage, with limited research reported, ,,,, which will be critically discussed in Section . As shown in Figure , the ILs-catalyzed strategy allows the discarding of the biomass pretreatment step, thereby giving a shorter process compared to the conventional strategy.…”

“…Table S3 of the Supporting Information summarize the pertinent references on the direct conversions of biomass to LA ,,,, and LE via ILs. The theoretical yield of LA/LE is determined based on a given cellulose content of biomass, whereas the process efficiency refers to the efficiency of biomass conversion to LA/LE based on the theoretical yield.…”