Ambient-pressure lignin valorization to high-performance polymers by intensified reductive catalytic deconstruction

Abstract

Chemocatalytic lignin valorization strategies are critical for a sustainable bioeconomy, as lignin, especially technical lignin, is one of the most available and underutilized aromatic feedstocks. Here, we provide the first report of an intensified reactive distillation–reductive catalytic deconstruction (RD-RCD) process to concurrently deconstruct technical lignins from diverse sources and purify the aromatic products at ambient pressure. We demonstrate the utility of RD-RCD bio-oils in high-performance additive manufacturing via stereolithography 3D printing and highlight its economic advantages over a conventional reductive catalytic fractionation/RCD process. As an example, our RD-RCD reduces the cost of producing a biobased pressure-sensitive adhesive from softwood Kraft lignin by up to 60% in comparison to the high-pressure RCD approach. Last, a facile screening method was developed to predict deconstruction yields using easy-to-obtain thermal decomposition data. This work presents an integrated lignin valorization approach for upgrading existing lignin streams toward the realization of economically viable biorefineries.

System-level integrative analyses for production of lignin hydrogels

“…The major contributor in this segment is the costly monomers used for the polymerization reaction (SBMA and MAAH in the case of grade A and NIPAAM in the case of grade B hydrogel). Similar findings have also been reported by O'dea et al 29 where the cost due to MAAH dominated the operating expenses while studying the process for synthesizing the lignin-based polymer. The second highest contributor was the feedstock cost and utility usage.…”

“…MAAH has also been reported to be a significant cost contributor to the minimum selling price estimation of lignin based pressure sensitive adhesives. 29…”

Vat 3D Printing of Bioderivable Photoresins – Toward Sustainable and Robust Thermoplastic Parts

“…The molecular structure of lignin results in a highly cross-linked and amorphous aromatic network; however, despite its recalcitrant nature, lignin can be deconstructed to produce a variety of small molecule aromatic compounds that are useful as building blocks for new value-added chemicals, pharmaceuticals, fuels, and polymers. ,− Macromolecular products based on lignin-derived starting materials have already demonstrated performance-advantaged characteristics in various areas, such as the production of elastomers, , commodity plastics, epoxy resins, ,, high- T g (glass transition temperature) materials, , and pressure-sensitive adhesives (PSAs) …”

Photocatalytic Depolymerization of Native Lignin toward Chemically Recyclable Polymer Networks

“…Consider the traditional pulping process as an example. The delignification methods produce the so-called technical lignin, which often leads to structural heterogeneity and undesired side reactions (e.g., condensation) and makes its subsequent chemical utilization challenging. , Recently, an alternative lignin-first strategy has emerged to directly convert native lignin in lignocellulose into value-added chemicals. ,, For instance, reductive catalytic fractionation (RCF) as a lignin-first approach produces a mixture of low molecular weight compounds from native lignin. − However, the mixture produced by RCF is often difficult to separate. Moreover, RCF tends to destroy high-value functional groups such as carboxylic acids, aldehydes, and aromatic rings, undermining the value of these products as precursors for chemical syntheses. ,− Indeed, most RCF studies focus on retrieving the thermal energy of the products by using them as fuels.…”