In this work, potential energy conservation schemes for the production of liquefied natural gas (LNG) have been studied. The analysis was based on a given process flowsheet with incomplete material and energy balances data for the liquefaction system. The process flowsheet was therefore subjected to rigorous simulations and data reconciliations. Data reconciliation approaches for the process flowsheet involved the combination of structural decomposition of complex units and systematic estimations of unknown variables. Data validation was performed against published process performance indicators and optimized by minimizing the sum of squared errors (SSE). The base case liquefaction system was selected from the flowsheet with the smallest SSE value of 0.002. The liquefaction system was of the mixed refrigerant cycle (MRC) type. Next, the process structure and the composition of the refrigerant were systematically modified to increase the thermodynamic performance of the liquefaction system. Three power reduction schemes have been proposed that include the process expander, the multistage compressions with intercoolers, and the multistage compressions with intercoolers incorporating the process expander. Each of these options was rigorously simulated and the best structural modification was selected for refrigerant optimization. It was found that the best option was the scheme running on an optimized mixed refrigerant composition and incorporating both the multistage compression with intercoolers and the process expander. This option resulted in a 31.9 reduction in power requirement against the base case, hence achieving the energy conservation objective. Copyright © 2008 by the American Institute of Aeronautics and Astronautics, Inc.