Fundamental Impact of Firing Syngas in Gas Turbines

This paper addresses the impact of burning syngas in a large size, heavy-duty gas turbine designed to run on natural gas while maintaining hot section life. The process used to produce syngas is not discussed here; we mainly focus on analyzing the issues related to switching from natural gas to syngas on the gas turbine hot sections and the possibility of reducing the firing temperature in order to maintain the durability of the hot metal section life. The analysis indicate that the power output for a syngas-fired turbine plant could be increased as much as 20–25% when compared with the same turbine fired at the same metal temperature as the natural gas, however this increase in power output is also accompanied by an increase in the moisture content of the combustion products due largely to higher hydrogen content in the syngas and the increased turbine flow which contribute significantly to the overheating of turbine component parts. Correlations based on the hydrogen content as well as the lower heating value of the fuels were obtained in order to determine specific firing temperature reduction necessary to obtain durable metal temperature.