Structural and Chemical Profiling of Hemp Hurds for Sustainable Bioproducts Within a Circular Economy Framework

Abstract

Lignocellulose biomass (LB) has gained interest as a second-generation renewable feedstock for producing bio-based products within a circular economy framework. Hemp hurds, a byproduct of industrial hemp processing, are one of the LB feedstocks that have gained attraction. This study examines the physicochemical properties of hemp hurds to evaluate their suitability as substrates for bioproduct synthesis. The chemical analysis of hemp hurds showed that the polysaccharide content is 53.4%, lignin is 20.8%, extractives are 15%, and ash is 4.35%. The moisture content is 6.34%, and the density is 1.0016 g/mL, indicating low porosity and a small surface area, which limits enzyme access to cellulose. Structural analysis using X-ray diffraction (XRD) indicated a crystallinity index of 40.20%, and the Fourier Transform Infrared Spectrophotometer (FTIR) confirmed the characteristic peaks representing cellulose, hemicellulose, and lignin at 3332 cm−1, 1734 cm−1, and 1510 cm−1, respectively. The Scanning Electron Microscope (SEM) revealed a tightly packed surface with smooth, low porosity, whereas the Thermogravimetric Analyser (TGA) indicated decomposition in phases for hemicellulose, cellulose, and lignin. The structural and chemical findings of hemp hurds characterisation suggest that they are a suitable raw material for producing various bio-based materials.