Power-to-X is gaining attention for large-scale renewable energy storage and long-distance transmission. Among its products, ammonia stands out as a promising hydrogen carrier for decarbonizing hard-to-abate sectors. Traditionally produced via the Haber-Bosch process using natural gas, ammonia synthesis faces challenges when integrated with Variable Renewable Energy Sources (VRES) like solar and wind due to their intermittency. This paper explores a flexible Power-to-Ammonia design combining alkaline electrolysis, cryogenic air separation, and the Haber-Bosch process. It integrates strategies like make-up gas modulation to enhance adaptability. Using thermochemical modeling, pinch analysis, and superstructure pseudo-dynamic simulation, the study analyzes key parameters, including ammonia synthesis conditions, electrolyzer efficiency, and renewable power productivity. Techno-economic and environmental indexes assess system performance against previous studies. Simulations focus on 500 tonNH3/day plants using Italian renewable power profiles from the national Transmission System Operator database. Flexible plant operation reduced production, requiring oversized systems VRES systems (> 400 MW) with a multi-source asset (installed power: 50% solar photovoltaic and 50% wind turbines). From the economic point of view these setups proved unprofitable in the current market of grey ammonia but foresee room for development for green system concepts (LCOA = 0.85–0.90 €/kg NH3). However, by implementing a new metric – the Levelized Cost od Avoided Emission LCAE, these solutions prove more convenient, being the least cost for ammonia decarbonization (0.70-75 €/kg CO2).
INVESTIGATION OF POWER-TO-AMMONIA SYSTEMS FLEXIBILITY THROUGH MAKE-UP GAS MODULATION
Arianna Baldinelli
Writing – Original Draft Preparation
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2025-01-01
Abstract
Power-to-X is gaining attention for large-scale renewable energy storage and long-distance transmission. Among its products, ammonia stands out as a promising hydrogen carrier for decarbonizing hard-to-abate sectors. Traditionally produced via the Haber-Bosch process using natural gas, ammonia synthesis faces challenges when integrated with Variable Renewable Energy Sources (VRES) like solar and wind due to their intermittency. This paper explores a flexible Power-to-Ammonia design combining alkaline electrolysis, cryogenic air separation, and the Haber-Bosch process. It integrates strategies like make-up gas modulation to enhance adaptability. Using thermochemical modeling, pinch analysis, and superstructure pseudo-dynamic simulation, the study analyzes key parameters, including ammonia synthesis conditions, electrolyzer efficiency, and renewable power productivity. Techno-economic and environmental indexes assess system performance against previous studies. Simulations focus on 500 tonNH3/day plants using Italian renewable power profiles from the national Transmission System Operator database. Flexible plant operation reduced production, requiring oversized systems VRES systems (> 400 MW) with a multi-source asset (installed power: 50% solar photovoltaic and 50% wind turbines). From the economic point of view these setups proved unprofitable in the current market of grey ammonia but foresee room for development for green system concepts (LCOA = 0.85–0.90 €/kg NH3). However, by implementing a new metric – the Levelized Cost od Avoided Emission LCAE, these solutions prove more convenient, being the least cost for ammonia decarbonization (0.70-75 €/kg CO2).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
