Utilization of cold energy of liquefied natural gas in air separation plant in a safer and More Energy Efficient Way.

LNG cold can be utilized to reduce specific energy consumption (SPC) in an air separation unit (ASU). LNG cold can be used to produce pressurized gaseous oxygen (PGOX), pressurized gaseous nitrogen (PGAN), liquid oxygen (LOX) and liquid nitrogen (LIN). The proposed configuration is safer than that proposed in a published paper by Tesch et al. (2017) where PGOX is produced by pumping LOX and vapourizing it in main heat exchanger (MHX) instead of getting pressurized in a compressor. Further, we avoid bringing flammable fuel LNG to the ASU premises. Nitrogen from ASU to the regasification terminal gets converted to LIN in a heat exchanger and the same returns to the ASU. Power consumption, the purity of the products, exergy destruction and exergy efficiency are determined by simulating the plant on Aspen Hysys 8.6TM process simulator. The results show that apart from improved safety, the exergy efficiency of the proposed system is higher than that of the configuration compared.