Thermodynamic performance study of large-scale industrial gas turbine with methane/ammonia/hydrogen blended fuels

Abstract

The fuel interchangeability range without any modifications was proposed within 5% of Wobbe index (WI) by the gas turbine manufacturers. The system modifications, especially in combustor, are needed with the out-of-range 5% of WI. In this study, the thermodynamic performances were studied with the fuels exceeding 5% of WI, the focused fuel compositions were ammonia and hydrogen for eco-friendly power generation and carbon neutrality. A performance analysis was conducted for a J-class gas turbine wherein ammonia and hydrogen were mixed with conventional liquefied natural gas (LNG) fuel. The maximum mixable ratio of ammonia is 76%, and fuels with higher mixable ratio cannot achieve a high turbine inlet temperature (1873 K). 100% hydrogen can be used with stable operation if the flame stability is guaranteed by developing a new combustor with conventional compressor and turbines. Environmental–economic analysis was also conducted to study the effect of carbon-neutral fuel on air pollution. Mixing hydrogen is a highly effective method to reduce the air pollutant tax; however, mixing ammonia is not suitable for decreasing air pollutants. As ammonia emits enormous NOx, an after-treatment system is required to use ammonia as a carbon-neutral fuel.