Optimization of Cold, Heat, Power and Carbon Quadruple Synergistic System with Green Ammonia in LNG

To address global warming and climate crises, the transition from fossil fuel-based energy systems to renewable energy is inevitable. In conventional cooling systems, this study introduces green ammonia into LNG pipelines to create a novel quadruple synergistic system integrating cooling–heating–electricity–carbon capture. Results demonstrate significant improvements in overall system efficiency. To comprehensively evaluate its engineering feasibility, we conducted energy balance, economic, life cycle assessments, and carbon footprint analyses based on system flow parameters. Key parameters in different subcycles─including heat source temperature, LNG pump outlet pressure, ammonia mass flow percentage, and Eva pinch temperature difference (PPTD)─were analyzed for their impacts. Additionally, discussions covered investment costs, variable expenses, clean production solutions, and carbon footprint evaluations to holistically assess system viability. Finally, 3D optimization algorithms were employed to optimize the system, achieving peak performance with an exergy efficiency of 67.26%, a product unit exergoeconomic cost of $75.21/GJ, and normalized levelized cost of electricity (LCOE) at 3.41 cents/kW h. Potential prospects include large-scale application in LNG terminals, data centers, and coastal industrial parks, providing a scalable engineering solution for synergistic energy supply and carbon reduction. This research fills the gap of insufficient integration of ammonia–LNG hybrid systems with quadruple energy supply and full-cycle assessment, offering a new paradigm for low-carbon multienergy systems.