2D and 3D Spectrum Graphics of the Chemical-Morphological Domains of Complex Biomass by Low Field Proton NMR Energy Relaxation Signal Analysis

The present paper describes novel low frequency (LF) ¹H NMR energy relaxation time signal analysis for mapping the different chemical and morphological domains in complex cattle manure (CM) and cattle forage (CF) biomass. Relaxation signals generated by different absorbed water pools and aliphatic chains are analyzed by specifically designed sparse representation methods and a convex optimization PDCO solver, for generating 2D T₁ (spin-matrix) vs T₂ (spin-spin) energy relaxation time spectrum graphics and 3D graphs that include ¹H population density. Using analytical spectral analyses and spiking assignment with material standards of the individual T₁ vs T₂ peaks in the generated CM graphics, a morphological and chemical domain dictionary was formulated demonstrating well resolved signal peaks and a better understanding of the different chemical and morphological structural organization within the complex biomass material. This benchtop proton LF-NMR relaxation sensor system and its signal generation into chemical-morphological spectrum graphics has the potential to significantly contribute to a rapid and accurate monitoring system for biobased industrial processes with significant applicability in, for example, biorefineries.