Abstract This article presents a real-time simulator of an agricultural biogas plant. The project contains biogas and biomass circuits simulation, as well as heating circuit simulation with a complete control system and visualization interface of the whole process. The software tool used to simulate the plant work is CFD ( Computational Fluid Dynamics ), which enables a user to create and test simulation objects based on fundamental physical laws related to fluid circuits and flows. The research work was concentrated on building simulation object reflecting real plant dynamics in the most precise way that can be achieved with the provided simulation tools. Presented simulation creates a possibility to minimize dangerous and undesirable situations on a real plant by manipulating of control parameters and observing simulated object reaction. The simulation results enable to optimize biogas production and operation costs. The simulator is intended to be an operator staff training material and can increase the operators’ reliability during plant’s operation. It is an important aspect in biogas plant risk management and it may reduce the requirements for safety instrumented system as well as the cost of their implementation.