Energy Valorization of Industrial Hemp Pressing Residues (Cannabis sativa L.) - Combustion, Anaerobic Digestion and LCA using OpenLCA

¹ Laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water and Environment, CERN2D, ENSAM, Mohammed V University in Rabat, Rabat 10100, Morocco
² Interdisciplinary Applied Research Laboratory, International University of Agadir, Universiapolis, Agadir 80000, Morocco
³ Laboratory of Spectroscopy, Molecular Modeling Materials, Nanomaterials Water and Environment-CERNE2D, Faculty of Sciences, Mohammed V University in Rabat, Rabat 10100, Morocco

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 13 May 2026

Abstract

The energy recovery potential of industrial hemp pressing cake (Cannabis sativa L.) is studied using a full Life Cycle Assessment (LCA), implemented in the open-source software openLCA v2.4 and coupled to the ecoinvent 3.10 database (cut-off system). Two processes are compared: (I) combined heat and power (CHP) cogeneration (direct combustion, η_e=25%, η_th=55%) and (II) anaerobic digestion (AD, BMP up to 248 NmL CH4/g VS). The ReCiPe 2016 Midpoint (H) impact method, combined with the IPCC’s GWP₁₀₀ factors, allows for the quantification of environmental impacts according to the system expansion (substitution) method. The results show that CHP, by substituting electricity from Morocco’s high-carbon electricity mix (approximately 650 gCO2eq/kWh), achieves a net Global Warming Potential (GWP) of -520 kgCO2eq per ton of treated waste. Anaerobic digestion, on the other hand, is only environmentally competitive if CH₄ leaks are kept below 3.5%. Finally, a substitution modeling module (polynomial approximation) enables multi-objective optimization of operating parameters, revealing that humidity control (less than 10% for combustion) and total heat recovery from the CHP system are the priority levers for action.