Power generation and recovery of higher hydrocarbons utilizing cold energy during LNG regasification

Liquefied natural gas (LNG) is stored and transported at cryogenic temperatures below –162°C. Despite the significant potential of the ultralow-temperature energy inherent in LNG for various applications, it is frequently squandered during regasification. While previous studies have proposed utilizing LNG cold energy for power generation and hydrocarbon recovery, none have explored the combined applications of these processes. Therefore, this study aims to leverage LNG cold energy during regasification for simultaneous power generation and natural gas liquids (NGL) recovery. Different power generation configurations using the Rankine and Brayton cycles are reviewed and compared to identify the most suitable power cycles and working fluid candidates. Different configurations for NGL recovery are also examined to optimize the utilization of LNG cold energy. The preliminary results of the proposed system are obtained using Aspen HYSYS software, incorporating natural water sources at ambient temperature as the heat source. The proposed system effectively produces ethane and liquefied petroleum gas (LPG), meeting the required sales gas specifications while generating an overall net power output. Furthermore, this paper investigates the impact of ambient temperature on process efficiency, providing valuable insights into the system’s performance under different environmental conditions.