Anaerobic digestion (AD) expansion as a renewable energy source offers environmental benefits, such as reducing mineral fertilizer use and preserving soil organic matter. However, poor AD performance can cause greenhouse gas emissions and nutrient loss, impacting efficiency. To address this, an innovative AD process chain (ADPC) model was developed to dynamically simulate biogas production, organic matter bioaccessibility, digestate phase separation, storage, and soil application, focusing on carbon and nitrogen dynamics. Evaluated against 5 lab-scale experiments and C/N soil dynamics without specific calibration, the model accurately reproduced trends (bias: 11% for biogas, r