Methane production from anaerobic digestion of date palm leaflet waste in Morocco

The recovery of date palm leaflet waste (DPLW), generated by palms through anaerobic digestion (AD) technology, attracts more attention because of its many economic, social, and environmental benefits. In this study, a laboratory-scale experiment using a continuous stirring tank reactor digester (CSTR) operating in mesophilic semi-batch mode was conducted to evaluate experimental methane production, biodegradability, and organic loading rate (OLR). Besides, a theoretical estimate of methane was assessed using a Buswell–Neave equation. Moreover, three modified kinetic models (Logistic, Gompertz, and Richards) were applied to adjust the experimental methane production from the AD of DPLW. This study showed that the experimental methane yield and biodegradability of DPLW were 133 NmL CH4/g VS and 33%, respectively, while the OLR was 2.76 kg VS/m3.d. The kinetic results showed that all three modified models (Gompertz, Richards, and Logistic) were useful for predicting methane production as a function of the added loads. However, the modified Gompertz model was the most suitable for experimental data, even under critical conditions. Indeed, the modified Gompertz model fitted the experimental methane production with an optimal correlation coefficient R2 = 0.998.