Integration ammonia cracking process and co-firing of natural gas in combined cycle power plant: A thermodynamic analysis

Abstract

The global energy sector is currently facing the dual challenges of meeting increasing energy demands while reducing greenhouse gas emissions. In this context, the utilization of ammonia (NH3) as a hydrogen (H2) carrier and its integration into power generation systems is gaining attention as a potential solution. This study presents a comprehensive thermodynamic analysis of the novel integration of an NH3 cracking process with a natural gas co-firing combined cycle power plant. Through the integration of the NH3 cracking process with the power plant, H2 can be transported more efficiently through NH3. The NH3–H2–N2 fuel mixture is produced through NH3 cracking, with a craking ratio of 52 % (48 % molar fraction of NH3), to ensure a similar laminar burning velocity to that of natural gas. Our analysis focuses on the efficiency implications and environmental impacts of incorporating NH3 as a sustainable energy source, particularly in terms of NOx emissions. The results demonstrate that by reducing the natural gas input, CO2 emissions can be significantly reduced. However, the decrease in exhaust gas mass flow rate limits its utilization in the steam turbine as part of a combined cycle, as a significant portion of the exhaust gas is utilized to crack NH3. Moreover, this study provides valuable insights into the feasibility and benefits of NH3 integration in power generation, thereby contributing to the ongoing discourse on sustainable energy solutions.