This paper presents a detailed lattice Boltzmann model (LBM) for simulating non-ideal gases and liquid-gas phase transitions. The model is designed to conserve momentum and can handle one-component fluid systems that obey non-ideal gas equations of state. The densities in the liquid and gas phases are determined from a temperature-like parameter, and the density profile at the liquid-gas interface is shown to be isotropic. The surface tension, which can be independently adjusted, is calculated and verified through numerical simulations. The model's behavior is compared with thermodynamic predictions, showing that it can correspond to an isothermal process under specific conditions. The analytical results are validated by numerical simulations, demonstrating excellent agreement. The paper also discusses the limitations of the model, particularly the lack of an energy conservation relation and a dynamic temperature equation, and suggests future research directions.This paper presents a detailed lattice Boltzmann model (LBM) for simulating non-ideal gases and liquid-gas phase transitions. The model is designed to conserve momentum and can handle one-component fluid systems that obey non-ideal gas equations of state. The densities in the liquid and gas phases are determined from a temperature-like parameter, and the density profile at the liquid-gas interface is shown to be isotropic. The surface tension, which can be independently adjusted, is calculated and verified through numerical simulations. The model's behavior is compared with thermodynamic predictions, showing that it can correspond to an isothermal process under specific conditions. The analytical results are validated by numerical simulations, demonstrating excellent agreement. The paper also discusses the limitations of the model, particularly the lack of an energy conservation relation and a dynamic temperature equation, and suggests future research directions.