Structure-function relationships between residence time distribution and lignocellulosic deconstruction and fermentation yield of wheat straw during reactive extrusion pretreatment.

Reactive extrusion is an effective pretreatment method for straw. However, the structure-function relationships between residence time distribution (RTD) in reactive extrusion and lignocellulosic deconstruction and fermentation yield of wheat straw remain unclear. Therefore, the RTD during reactive extrusion of wheat straw was calculated using the pulse method, and its physicochemical properties before and after pretreatment, as well as the yields obtained from microbial-enzymatic co-fermentation, were determined to establish the structure-function relationship between the two. The results showed that RTD varied significantly under different operating conditions. After pretreatment, lignocellulose was effectively deconstructed, with lignin removal ranging from 13.04% to 21.71%. The total sugar yield and lactic acid increased to 2.27-2.95 times and 1.50-1.61 times those of untreated samples, respectively. The structure-function relationships indicated that an appropriate mean residence time and sufficient mixing during extrusion are beneficial for lignocellulosic deconstruction, thereby enhancing enzymatic hydrolysis and fermentation performance of wheat straw. This study provides a theoretical basis for the sustainable fractionation and efficient utilization of lignocellulosic biomass via reactive extrusion.