Methane production from date seed cake (Phoenix dactylifera L.) using mesophilic fed-batch anaerobic digestion

• Published in: Cleaner Waste Systems Vol. 2; p. 100009
• Main Authors: Ourradi, Hamza, Lahboubi, Nabila, Habchi, Sanae, Hanine, Hafida, El bari, Hassan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2022
• Subjects: Date seed cake; Fed-batch anaerobic digestion; Kinetic modeling; Methane yield coefficient; Phoenix dactylifera L; Methane yield coefficient; Date seed cake; Kinetic modeling; Phoenix dactylifera L; Fed-batch anaerobic digestion
• ISSN: 2772-9125; 2772-9125
• DOI: 10.1016/j.clwas.2022.100009

Date seeds (Phoenix dactylifera L.) are considered as valuable form of lignocellulosic biomass and are noted for their high content of biodegradable organic molecules. One of the modes of exploitation of this biomass is oil extraction, which leads to the production of a valuable by-product: date seed cake. In this work, anaerobic digestion of this widely available resource is investigated in order to assess the potential for energy recovery by methane production using a laboratory-scale digester operating in batch-fed mode with continuous stirring within a mesophilic temperature range. During the anaerobic digestion process, pH, alkalinity, and volatile fatty acids were altered to maintain good bioconversion conditions. The results show that the reactor performed with good stability as the load increased. Maximum methane production was 485.66 Normal mL (NmL) at 3.5 g VS (volatile solid)/L load with biodegradability of 35.93%. The methane yield coefficient was 173 Nml CH4/g VS. Furthermore, 0.83 g VS/L.d provides the optimal organic loading rate. In addition, modified kinetic models were applied to model experimental methane production from date seed cake substrate to obtain kinetic parameters. the results show that the modified Gompertz model was the most adjusted to the experimental results, with a correlation coefficient of R2 = 0.9931. •Date seeds cake are promising organic waste to use for methane as clean and renewable energy by anaerobic digestion.•The biogas production from date seeds cake seems to be a suitable way to close the loop.•The bioconversion of 35.93% of organic matter to biogas provides a yield of 173.01 NmL CH4/g VS.•The modified Gompertz model was the most adjusted to the experimental results.