Economic cost and performance analysis of a novel trigeneration scheme utilizing CO₂ capture and solid oxide electrolysis units

A novel integrated process is presented for power, hydrogen, and heat generation through water electrolysis in the presence of carbon dioxide (CO₂) captured from a power plant flue gas. The proposed system consists of a CO₂ capture unit, a solid oxide electrolysis unit (SOEU), a steam power cycle, a heat recovery unit (HRU), and an ammonia power cycle. The overall energy and exergy efficiencies of the power plant are 34.84% and 83%, respectively. In addition, it is demonstrated that the total exergy destruction and exergy destruction rate of the proposed cycle are 1357576 kW and 0.081 GJ/kWh. The total net output power of the proposed power plant is determined at 60046.6 kW. Heat recovery values in SOEU and CCU units respectively equal 1158 and 22.17 MW. Based on the exergy analysis, the largest exergy destruction happens in the HRU unit (79%) with a value of 1066340 kW. The environmental analysis indicates that the direct CO₂ emission rate is zero and the indirect one is 0.53 kg_CO2/kWh. Meanwhile, the economic analysis shows that the total annual cost of the proposed power plant is 75.36 M$ and the production cost of electricity equals 0.15 $/kW.