Assessing the Viability of Recovery of Hydroxycinnamic Acids from Lignocellulosic Biorefinery Alkaline Pretreatment Waste Streams

TLDR

Hydroxycinnamic acids p‑coumaric and ferulic acids diversify products from grass‑fed lignocellulosic biorefineries. The study altered p‑coumaroyl‑CoA monolignol transferase expression to modify lignin‑bound pCA in Zea mays, then processed the biomass in a lab‑scale alkaline‑pretreatment biorefinery and performed a baseline technoeconomic analysis to identify where to focus future plant‑design and biomass‑utilization research. The authors conclude that plant engineering should prioritize accumulating either pCA or FA while suppressing the other, and that technoeconomic analysis shows extraction titers above 50 g kg⁻¹ are required for economic viability.

Abstract

The hydroxycinnamic acids p-coumaric acid (pCA) and ferulic acid (FA) add diversity to the portfolio of products produced by using grass-fed lignocellulosic biorefineries. The level of lignin-bound pCA in Zea mays was modified by the alteration of p-coumaroyl-CoA monolignol transferase expression. The biomass was processed in a lab-scale alkaline-pretreatment biorefinery process and the data were used for a baseline technoeconomic analysis to determine where to direct future research efforts to couple plant design to biomass utilization processes. It is concluded that future plant engineering efforts should focus on strategies that ramp up accumulation of one type of hydroxycinnamate (pCA or FA) predominantly and suppress that of the other. Technoeconomic analysis indicates that target extraction titers of one hydroxycinnamic acid need to be >50 g kg