Life-cycle analysis of functionalized lignocellulosic sugars as biobased substitutes for polymers and solvents

A new strategy relying on aldehydes to stabilize reactive intermediates during the fractionation of lignocellulosic biomass has recently been developed. In addition to producing a highly digestible cellulose pulp and an uncondensed acetal-stabilized lignin which can be efficiently depolymerized, Aldehyde-Assisted Fractionation yields acetal-stabilized xyloses with interesting properties for the chemical industry. To determine the ability of new bio-based products to be sustainable substitutes to existing petrochemical products, we must assess early the environmental impacts of its production process. In this work, we will present a comparative cradle-to-gate life-cycle analysis of two novel xylose-derived molecules and their applications. Diformylxylose (DFX), a new polar aprotic solvent (Komarova et al., 2021), can be produced in a single step from agricultural wastes. By using a carboxylic acid-functionalized aldehyde, we can also directly produce a bioplastic monomer, dimethylglyoxylate xylose (DMGX), with similar properties to PET precursors (Manker et al., 2022). This functionalized building block could substitute petro-based monomers in various polymers, such as polyamides, which we investigated in this study. Different process configurations, from xylose or corn cobs, have been modelled with Aspen Plus® to provide the material and energy inventory. DMGX was shown to have a 20% lower global warming potential than terephthalic acid in a conservative scenario, while its polyamide product, assuming a fully biobased process, could avoid up to 93% of the emissions of Nylon 6,6 manufacturing. Moreover, the biogenic carbon in corn cobs could off-set more than the total emissions from the DFX production process, therefore providing a renewable solvent.