Statistical Assesment of Biomass Homogenization for Controlling Lignin Variability in Coconut Fiber Residues

Abstract One of the main limitations affecting the reproducibility of lignocellulosic biomass conversion processes is the compositional variability of the raw material. This study evaluates a simple homogenization strategy to stabilize lignin content in coconut fiber residues, assessing a 1:1 composite substrate from two geographically distinct sourcing lots in the Colombian Pacific (Cauca and Nariño) for process standardization. Because the Van Soest method calculates fiber fractions by sequential subtraction, one-way ANOVA revealed statistically significant differences between the two regional lots in all four structural fractions (cellulose, lignin, hemicellulose, and ash), with ash and hemicellulose showing the strongest effects. Given its dominant mechanistic role in biomass recalcitrance and chemical reactivity, lignin was selected as the critical control variable for subsequent equivalence and capability analyses. Two One-Sided Tests (TOST) for equivalence failed to demonstrate that the lignin content of the blend was practically equivalent to either regional source under a ± 2.5 margin, supporting the use of a blended substrate to moderate compositional extremes. A Process Capability Analysis (Cp/Cpk) showed that the homogenization protocol produced a stable, normally distributed system ( p = 0.547, indicating no significant deviation from normality) with a Cpk of 0.82; although this value remains below the conventional industrial benchmark of 1.33, blending contained 98.6% of the composite’s lignin content within the regional natural limits (46.29–55.94%), representing a substantial reduction in variability relative to the unblended sources. This study does not aim to characterize coconut fiber itself, but to establish a statistical framework to transform compositional variability into a reproducible chemical substrate.