Complete Chemical Analysis of Carmagnola Hemp Hurds and Structural Features of Its Components

As interest in lignocellulosic biomass as a feedstock for conversion into biofuels is steadily growing, analysis of its components becomes ever more important. The complete chemical composition of waste hemp hurds from the industrial variety “Carmagnola” has been determined to optimize its utilization as a raw material. The results from chemical analysis show that hemp hurds contain 44.0% alpha-cellulose, 25.0% hemicellulose, and 23.0% lignin as major components, along with 4.0% extractives (oil, proteins, amino acids, pectin) and 1.2% ash. Structural and physicochemical properties of hurds components were analysed by FTIR or GC/MS. The data revealed that isolated components are pure and comparable to standard components. Acetone extractives show higher total phenolic content and antioxidant capacity compared with lignin and dichloromethane extractives. Water extractive shows the presence of proteins (1.6%), free amino acids (0.02%), and pectin (0.6%). The degree of esterification of pectin was estimated to be 46.0% by FTIR and enzymatic hydrolysis. The results of this study show that Carmagnola hurds contain low amounts of ash and high amounts of carbohydrates compared with other varieties of hemp hurds; therefore they can be considered as a potential feedstock for biorefinery.