(20b) Development of an Integrated Allam-Cycle Power Complex Coupling Air Separation Unit and Ammonia Plant

With the worldwide shale gas boom, the natural gas fired Allam cycle power plant has been increasingly attractive due to its high energy efficiency with NOx emission free and the capability of capturing the produced CO₂ and water for other industrial uses. By taking advantages of these merits, this paper for the first time has developed an integrated Allam-cycle power (A3) complex, which integrates Allam power cycle, air separation unit (ASU), and ammonia plant together to simultaneously produce power, fertilizer, water, and, pipeline-quality CO₂ efficiently and economically. The developed A3 complex is highly integrated with material and energy streams among the three process, where the ASU will provide pure O₂ to and in turn be powered by the Allam power cycle; meanwhile, ASU will also provide pure N₂ as a feedstock to the ammonia plant, which will be heated by waste streams from the Allam cycle. The developed large-scale A3 complex has been demonstrated via rigorous modeling and simulation with Aspen Plus simulator. Its economic and environmental performances have also been systematically evaluated to demonstrate its excellence.

This study conducts an innovative design of A3 complex with rigorous model and process simulation. Another achievement in this paper is the economic analysis of A3 complex for justifying the improvements and advantages of integrated plants compared with the individual plant. Furthermore, the integrated new process has been virtually demonstrated to be economically sound, technological viable, and environmentally benign due to the comprehensive utilization of cheap natural gas resource as well as heat and work integrations among different process units.

Keywords: Allam cycle; power plant, air separation unit; ammonia plant; process simulation