Small-scale air separation process utilizing cold energy from LNG satellite station

Abstract

A novel small-scale air separation process was proposed to effectively utilize the high-quality cold energy from liquefied natural gas(LNG) satellite station,according to its feature of time-dependent fluctuation.The process can accommodate the fluctuating LNG flow rate by adjusting the circulating nitrogen gas and by reversely inputting liquid nitrogen to meet the refrigeration demand when the LNG cold energy is insufficient.Simulations were carried out in four LNG flow rate cases with the process software HYSYS.The results show that producing liquid nitrogen when LNG is excessive and reversely inputting liquid nitrogen when insufficient can reasonably balance the fluctuating LNG cold energy.The compressor working at low temperature in traditional systems can be eliminated through optimizing the process,which then avoids the associated technical difficulties.