Natural gas power plants integrated with a carbon capture process, have recently attracted a lot of attention due to their capability of synergizing with renewable technologies and decarbonization of the power industry. The natural gas plant is fueled by liquefied natural gas at extremely low temperatures and is subsequently regasified. During regasification, a substantial amount of cold energy is available which is conventionally wasted. Furthermore, the integration of the carbon capture process poses a significant energy penalty on the system. This study, therefore, investigated the optimal utilization of the cold energy of the liquefied natural gas and the configuration of the post-combustion carbon dioxide capture process for the natural gas plant. Firstly, the carbon dioxide capture process was modified to reduce its thermal energy requirement. Secondly, the application of liquefied natural gas as a heat sink for the organic Rankine cycle was investigated. Subsequently, an alternative application of liquefied natural gas cold energy in the carbon dioxide compression process was evaluated. The results show that the modified carbon dioxide capture process reduces the thermal energy requirement by 12.8% and improves the efficiency of the power plant by 0.6%. The optimized organic Rankine cycle generates 4.9 MW electrical power using cold energy. In comparison, the intensified compression process integrated with liquefied natural gas regasification reduces the compression power by 7.15 MW, outperforming the application of liquefied natural gas in power generation. Thus, the optimal utilization of liquefied natural gas cold energy is in the carbon dioxide compression process as it improves the net efficiency and reduces the footprint of the liquefied natural gas cold energy utilization process. The modified carbon dioxide capture process and intensified carbon dioxide compression process using liquefied natural gas cold energy can enhance power generation by 13 MW and reduce the efficiency penalty from 6.1% to 4.8%.
Bibliographical noteFunding Information:
This work was supported by the “Local Demand Customized R&D Support Project” (Project: Recycling of greenhouse and by-products gases utilizing low-grade waste heat from industrial complex) through the Korea Institute of S&T Evaluation and Planning (KISTEP) funded by the Ministry of Science and ICT, Republic of Korea.
© 2021 Elsevier Ltd
- Intensified CO Compression Process
- Liquefied Natural Gas Cold Energy Utilization
- Modified CO Capture Configuration
- Organic Rankine Cycle
- Post-Combustion CO Capture
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Nuclear Energy and Engineering
- Fuel Technology
- Energy Engineering and Power Technology