Perspective on Overcoming Scale-Up Hurdles for the Reductive Catalytic Fractionation of Lignocellulose Biomass

Abstract

In the last 5 years, reductive catalytic fractionation of lignocellulose biomass has emerged as a promising biorefinery concept that combines biomass fractionation with the preservation of chemical functionality in its products. Although significant efforts have been made in optimizing this technology on lab scale, the implementation on a larger (pilot) scale is still in its infancy. In our own search for the scale-up potential of this technology, we faced several fundamental and technical research questions that, to this day, remain unanswered. These fundamental questions are related to four main aspects of RCF, the lignocellulose feedstock, the operating pressure, the redox catalyst, and the solvent. In order to inspire future multidisciplinary research in the RCF community, these scale-up challenges are presented and discussed via multiple angles combining chemical process hurdles with more technical aspects, such as reactor design and process consequences.

β‐Zeolite‐Assisted Lignin‐First Fractionation in a Flow‐Through Reactor**

“…Homogeneous acid addition is known to increase β-O-4 bond cleavage through hydrolysis, leading to a higher delignification rate [38], [28] . Nevertheless, acid-catalyzed lignin depolymerization may also lead to more severe lignin recondensation [19] . Thus, we evaluate the co-addition of a homogeneous acid on the monomer yield.…”

Guidelines for performing lignin-first biorefining

“…In addition, other factors, such as process economics, scale-up, and safety of operation, influence this choice. 172 The two primary reactor configurations reported to date in lignin-first biorefining are batch and flow-through (Fig. 3).…”

“…Improved analytics and experimental standardisation, as described here, will allow more effective and quantitative comparisons of studies across the literature, which will in turn enable generation of rigorous process inputs for economic and sustainability modelling, towards robust and realistic scale-up. 172 To this end, industrial implementation of lignin-first processes would represent the ultimate success for this field. a technology company making plant-based alternatives to petrochemicals.…”

Fast screening of Depolymerized Lignin Samples Through 2D‐Liquid Chromatography Mapping

“…[ 1 , 2 , 3 ] As it is the cheapest and most abundantly available inedible biomass, lignocellulosic biomass is commonly recognized as the most scalable and economically viable bio‐source to produce both bio‐fuels and high value chemicals. [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ] Lignocellulose consists of three highly functional biopolymers, namely cellulose, hemicellulose and lignin. The latter consists of functionalized aromatic building blocks, which are linked through mostly ether (C−O) and, to a lesser extent, carbon‐carbon (C−C) bonds, making it the largest renewable source of aromatics.…”

“…The latter consists of functionalized aromatic building blocks, which are linked through mostly ether (C−O) and, to a lesser extent, carbon‐carbon (C−C) bonds, making it the largest renewable source of aromatics. [ 7 , 10 , 11 ] As a result, lignin depolymerization into functionalized bio‐aromatics, i. e., monomers, dimers and oligomers, will become the main bio‐based route towards sustainable aromatic chemicals and building blocks for polymer synthesis or other high value applications. [ 5 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ] Unfortunately, most polysaccharide focused industries discard lignin as a waste product.…”