Novel ammonia-driven chemically recuperated gas turbine cycle based on dual fuel mode

Abstract

The potential safety hazards of hydrogen are relatively large due to its high flame propagation speed, strong permeability, small quenching distance and wide flammability limits. Decarbonization movement around the world has already driven ammonia (NH3) to become a potential solution for carbon-free economy and power generation with well-established infrastructure. Based on the principle of complementary fuel advantages and integrated cascade energy utilization, this study innovatively develops a novel power cycle based on a partial ammonia decomposition chemical reaction. The new design significantly ameliorates the problems of incomplete combustion of ammonia, as well as the safety hazards of hydrogen. By integrating with a chemically-recuperated unit, the exhaust heat can be fully utilized since the low-temperature waste heat is further used for evaporation of liquid NH3 and NH3 cracking processes. The thermal efficiency in the new design reaches 35.48–36.09% which is at least 21.67% higher than that (29.16–31.79%) in the reference system. The optimal condition is found as the ammonia split ratio reaches the maximum at 1 with a H2 molar ratio of 62.80–64.38%. The power generation efficiency can be improved to 43.55–43.90%, showing obvious advantages over pure ammonia condition. For a future carbon-free economy, this study should provide a new and efficient way for ammonia utilization.