Modeling and Simulation of Biomethane Injection in a Gas Distribution Network in Uzbekistan Towards a More Secure and Green Energy Supply

This study assesses the potential of biomethane integration into a gas distribution network to improve supply reliability under constrained operating conditions. A steady-state, isothermal network model based on graph theory and a SIMPLE-type iterative algorithm was developed to simulate pressure distribution and mass flow in a real urban gas network in Margilan, Uzbekistan. The results show that under winter peak-demand conditions, only 30–35% of consumers satisfy the minimum pressure requirements, while under reduced summer demand, supply coverage remains limited to about 46%, indicating significant hydraulic constraints. Increasing the regulator pressures could theoretically improve supply coverage, but this is impractical due to operational limitations at the transmission level. As an alternative, biomethane injection into the medium-pressure network was investigated. A single-point injection strategy increases supply coverage to 94%, while a multi-point configuration achieves full network saturation within allowable pressure limits and with lower total injection. The novelty of this work lies in the quantitative evaluation of biomethane injection strategies in a real gas network and in the application of a SIMPLE-type iterative algorithm to a compressible gas flow simulation in complex distribution systems.