One‐Step Lignocellulose Fractionation by using 2,5‐Furandicarboxylic Acid as a Biogenic and Recyclable Catalyst

Abstract

To develop novel biorefinery concepts, the use of bio-based catalysts and solvents must be aligned with the principles of green chemistry. In this context, biogenic 2,5-furandicarboxylic acid (FDCA) is a very promising yet underused molecule with high potential for application as an acid catalyst, combining feasibility and sustainability with efficient and straightforward recovery. In this study, FDCA was evaluated as a catalyst in the recently developed OrganoCat pretreatment, a biphasic lignocellulose fractionation system. The catalyst was investigated for the efficient fractionation of the three main components-lignin, cellulose and noncellulosic sugars-with particular focus on the lignin quality, on the effect on enzymatic hydrolysis of the cellulosic residue, and on the noncellulosic sugar extraction. To address recovery of FDCA from the OrganoCat system, a method was developed, leading to the recovery of >97 % of FDCA with a spectroscopic purity of >99 %, maintaining full activity in consecutive runs.

Multiscale analysis of lignocellulose recalcitrance towards OrganoCat pretreatment and fractionation

“…In general, we could observe that at the highest temperature (160 °C), a similar amount of hydrolyzed sugars was measured compared to 150 °C (Additional file 1: Table S1). Due to the higher temperature, a larger quantity of the sugars is presumably converted to furans and, therefore, the observed amount of sugars did not increase, which is consistent with the previous research [30]. OrganoCat processing aims at full valorization of all three product streams.…”

“…OrganoCat pretreatment was conducted using two different catalysts: (1) oxalic acid (140 °C, 3 h, 0.1 M oxalic acid referred to water volume) and (2) 2,5-furandicarboxylic acid (3 h, 0.1 M FDCA in both cases referred to water volume) at three different temperatures (140 °C, 150 °C, and 160 °C) due to FDCA's higher thermal stability compared to oxalic acid [30]. For each set of conditions, triplicates were produced to assure robustness and reproducibility of the results.…”

“…The pulp, now enriched in cellulose, remains as a solid in the aqueous phase and can be filtered off and thus recovered. The three resulting product streams, cellulose-enriched pulp, hydrolyzed monosaccharides, and lignin can be separated and the water, solvent, and catalyst recycled [28][29][30].…”

Recent Efforts to Prevent Undesirable Reactions From Fractionation to Depolymerization of Lignin: Toward Maximizing the Value From Lignin

“…As part of this effort, several fractionation processes have been developed and introduced, which utilize new types of solvents and catalysts. This includes ionic liquids (Shi et al, 2014Sun et al, 2016;Xu et al, 2016;Dutta et al, 2017), deep eutectic solvents Xu et al, 2018), γ-valerolactone (GVL; Luterbacher et al, 2014Luterbacher et al, , 2015Shuai et al, 2016b) and 2,5-furandicarboxylic acid (Weidener et al, 2018). Basically, the new solvent system demonstrated its applicability under mild processing conditions without strong acid or base catalysts, which minimizes carbocation-and quinone methides-induced condensation and repolymerization reactions.…”

Cyclopentyl Methyl Ether (CPME): A Versatile Eco‐Friendly Solvent for Applications in Biotechnology and Biorefineries

“…[5] Hence, biorefineries may produce bio-based solvents as well, either to be delivered to chemical plants, or to be used in-house for biorefining procedures.A mongs uch solvents, 2-MeTHF has found applications for biorefinery-like strategies,s uch as lignocellulosic pretreatment, furan production, andother subsequent valorization steps, typically setting up biphasic media for in situ product extraction. [39] In general, solvents are an ecessary element for many steps in biorefineries. [40] In this regard, CPME has also startedt ob et ested as an ecofriendly solventf or use in biorefineries.O ne such area of research is the production of furans, namely furfural from pentoses (mostly xylose) [41] and HMF from hexoses (mostly glucose).…”