A Novel Conceptual Design by Integrating the Hot and Cold Sections of Liquefied Natural Gas Process for Economic and Energy Savings

Liquefied natural gas (LNG) is an important energy source in international energy markets. To reduce its high production cost, this research examines and enhances the hot and cold sections of the LNG process, consisting of pre-separation, gas dehydration, condensate stabilization, acid gas removal, acid gas enrichment, sulphur recovery, fractionation, liquefication, nitrogen removal, helium extraction, and LNG storage tank. The aforementioned units were integrated and analyzed using pinch analysis to achieve maximum energy savings, conducted through the Aspen energy analyzer V10, whilst plant simulations were carried out using Aspen HYSYS V10. In the heat integration, the heat exchange network (HENs) was created utilizing pinch analysis techniques in AEA to estimate the maximal heat recovery and reduce emissions associated with the LNG supply chain. Where the two pinch points considered were 2ºC and 10ºC. The energy analysis revealed ten HENs consisting of 16 heaters, 29 coolers, and 11 process heat exchangers for the base case simulation. Whereas the total energy required for the simulation of the base scenario is 521.2 MW, and CO₂ emissions from indirect sources were 2517 tonnes/day. Following the integration of the units, the amount of energy used was minimized by 28%, and carbon emissions were reduced by 28.02%, amounting to 1812 tonnes/day.