Abstract
Energy efficiency and carbon capture and storage (CCS) are two key levers to attain global warming targets. Integration of various industrial and energy processes as well as complementary use of fuels with low carbon intensity such as natural gas with renewable sources will enable to mitigate environmental impacts in a cost competitive manner. This study proposes one such opportunity through integration of LNG cold exergy utilization for liquid N2 energy storage during regasification coupled to a novel NH3-electricity co-production scheme with CCS. A techno-economic benchmarking between standalone NH3 production process with net electricity imports (Case A), an integrated co-production solution (Case B) and non-integrated co-production plant with a standard combined cycle for power generation (Case C) is performed. Base economic assumptions are a natural gas price of 6.5 €/ton, CO2 tax of 100 €/ton, NH3 selling price of 400 €/ton and electricity average price of 80 €/MWh. At varying power generation capacity factors CFEl ranging from 30 to 50%, the electricity price premium required by the co-production schemes to break even with Case A is 2.5–9.9 €/MWh lower for Case B compared to Case C, with a premium as low as 12.9 €/MWh at 50% CFEl for the former when 2 days' worth of energy storage capacity is constructed. Thus, integration improves economic competitiveness for short storage times, applicable to regions with reliable year-round solar resources. However, the competitive advantage disappears when storage periods longer than one week are considered, such as power systems with high wind shares or seasonal solar availability.
