A process for the production, treatment and combustion of synthesis gas for the purpose of generating electric power is disclosed. The synthesis gas is produced from a solid, carbon-containing fuel with the aid of an oxygen-containing gas and treated by a slag-separating device and a device separating alkalis. Subsequently, the synthesis gas produced is fed to an expansion turbine where the pressure energy is used for generating power. On account of the treatment and separation of alkalis the expansion turbine is protected from corrosion and mechanical impact. The expanded synthesis gas is then burnt under pressure and the combustion is used in a combined-cycle process using a gas turbine, steam generator and steam turbine for generating power. The process thus has an increased efficiency. Apparatus for use of the process is also described.