(362b) Optimal Liquified Natural Gas (LNG) Cold Energy Utilization in an Allam Cycle Power Plant

Oxygen-combustion power cycles are an alternative technology for electricity generation to facilitate carbon capture and storage (CCS). Among oxy-combustion power cycles, the Allam cycle is one of the most promising technologies for power generation in terms of both efficiency and economics. Besides, the Allam cycle can also achieve the near-zero emission target at a much lower cost compared to conventional fossil fuel power plants. However, in the Allam cycle, the flue gas carbon capture process and recycled flue gas compression process consumes considerable compression work. If the compression work can be decreased, the energy efficiency of the system can be improved further, which can enhance the competitiveness over other power generation technologies. When the fuel of the power plant is Liquified Natural Gas (LNG) instead of natural gas, the LNG cold energy can be utilized to reduce the compression work of carbon capture process and recycled stream compression work in the Allam cycle. In this study, we investigated different ways to utilize the LNG cold energy for both stand-alone power plant and a combined LNG regasification and power generation cogeneration system. A simulation-based optimization framework is adopted to optimize different systems. Based on the optimization results, the optimal LNG cold energy utilization way is determined. The results indicate that the direct integration of LNG cold energy and the flue gas carbon capture process performs well for the stand-alone power plant, while the organic Rankine cycle integration with the LNG cold energy and recycled flue gas is the best choice for the cogeneration system.