Comparative study of CO2-N2 and N2-N2 dual expansion in natural gas liquefaction process

Abstract

The processes were modelled using the Aspen Hysys version 11. The paper compared two refrigeration systems with different refrigerants, CO2-N2 and N2-N2, and their expenders. The parameters compared are the liquefaction power, specific power, production capacity, and heat duty of the expander cycle. The liquefaction power of CO2-N2 (547.669kW) is lower than that of N2-N2 (815.85kW). The specific power consumption for CO2-N2 was 0.44096kW/kg, and for N2-N2 was 0.6569kW/kg. The production capacity N2-N2 gave a higher value of 6945.6MTPA than CO2-N2 4904.38MTPA.