Design and Evaluation of High-Safety Differential Pressure Power Generation Technologies for Hydrogen and Ammonia Gas

The use of differential pressure energy for green hydrogen and ammonia comes with significant safety challenges. Two zero-emission technical schemes—one based on magnetic coupling transmission and another based on dual magnetic fluid seals—were proposed and designed. The energy performance of both schemes was first analyzed for a DN200 pipe using the DWSIM software (Version 8.6.6). Subsequently, the levelized cost of electricity and the dynamic payback period were evaluated and compared. The results show that the magnetic coupling transmission scheme exhibits relatively low energy efficiency (54.9–61.7%), whereas the scheme based on dual magnetic fluid seals is more complex yet achieves higher energy efficiency (65.8–67.1%). The levelized electricity cost of both schemes under a differential pressure of 0.5 MPa is estimated to be lower than the feed-in tariff of coal-fired power plants in China, and the dynamic payback period is estimated to be less than 5.5 years. Overall, both schemes provide benefits in energy savings and profitability. These schemes warrant further experimental investigation and pilot testing.