Comparative study of energetic potential from anaerobic digestion and direct combustion of date palm wastes

Two different scenarios are analysed for converting date palm waste from a Moroccan oasis into energy: direct combustion of the date palm waste or anaerobic digestion of the waste combined with direct combustion of the digestate. Experimentally measured values are used to calculate output energy for the scenarios. This work aims to evaluate the technical and environmental feasibility of converting date palm waste from a Moroccan oasis into energy. In this study, two different scenarios were analysed. The first proposed scenario is the valorization of the date palm substrates using direct combustion (thermochemical conversion) to produce energy. The second proposed scenario is the valorization of the substrates using combined anaerobic digestion of the substrate and direct combustion of the digestate. In this study, two different date palm wastes are: empty fruit bunch (EFB) and palm leaflet (PL). The experimental lower heating values of the digestates studied are 12.93 and 12.71 MJ/kg, respectively. The results show that using Scenario 1, the estimated output energies for the EFB and PL waste were 1.13 and 1.17 MWh, respectively. Using Scenario 2, the EFB and PL output energies were 1.27 and 1.39 MWh, respectively. The study revealed that the combined process is possible as an alternative way to produce energy. Furthermore, combining anaerobic digestion and direct combustion of lignocellulosic waste can contribute to reducing greenhouse gas emissions.