Conceptual design of LNG regasification process using liquid air energy storage (LAES) and LNG production process using magnetic refrigeration system

摘要

This paper presents a theoretical study (conceptual design) aimed at improving the performance of both LNG production and regasification processes. First, a newly process configuration of liquefying natural gas using magnetic refrigerator is developed for a small scale liquefaction process for energy saving purpose. Magnetic refrigeration system has not been utilized for liquefying natural gas up to now. The results show that the new process configuration results in similar to 74.4% energy savings (SEC 0.0752 kWh/kg) as compared to the SMR-APCI process which has been reported to have the lowest SEC among other small scale LNG processes. The COP of the proposed process has a high value of 6.69. Moreover, a novel process configuration of LNG regasification integrated with Stirling engine and liquid air energy storage (LAES) system is developed for enhanced power production and flexible energy storage options. Stirling engine has not been used for such a system up to now. The results indicate that the proposed LNG-LAES-ST process gives maximum round trip efficiency (192%), exergy efficiency (70.88%) and energy storage capacity (0.4785 kW/kgLNG) when compared to six of the best processes which were recently reported in literature. Two novel processes are modelled by Aspen Hysys and Peng Robinson thermodynamic model.