Modeling and Analysis of Biogas Production from Cow Manure: Simulation Study Using SuperPro Designer and Performance Evaluation

This study presents a steady-state simulation model for biogas production using cow manure as the feedstock, implemented in SuperPro Designer (Version 10). The main goal is to assess process performance under defined operating conditions: mesophilic temperature (37°C), pH 7, and a hydraulic retention time of 30 days. The manure composition on a dry basis was set as 18.0% protein, 24.0% fat, and 58.0% carbohydrates, mixed with water at a 1:1 ratio to produce 1000 kg/h of feed slurry (wet basis: 8.7% carbohydrates, 2.7% protein, 3.6% fat, and 85% water). The simulation includes thirteen stoichiometric biochemical reactions representing hydrolysis, acidogenesis, acetogenesis, and methanogenesis within a continuous anaerobic digester. Results show a biogas production rate of 25.42 kg/h, composed of methane (76.45%), carbon dioxide (22.19%), hydrogen sulfide (0.60%), and hydrogen (0.74%). The methane yield reached 0.388 Nm 3 CH 4 per kg of volatile solids added, with a volatile solids destruction rate of 45.2%. A sensitivity analysis identifies carbohydrate conversion as the most influential parameter on methane yield, which varies from 0.372 to 0.404 Nm 3 /kg VS under a ±20% change. Comparisons with previous simulation studies confirm that the results are within acceptable ranges reported in the literature, supporting the model’s usefulness as a conceptual design tool. This model provides a preliminary framework for designing biogas processes from bovine manure, while acknowledging that experimental validation, kinetic modeling, and uncertainty analysis are necessary before practical application.