The integration of liquid air energy storage (LAES) and air separation units (ASUs) can improve the operation economy of ASUs due to their matching at refrigeration temperature. A process flow of an ASU with energy storage utilizing the distillation potential of the ASU to absorb the released air due to storing energy (i.e., the energy storage air) is proposed. Its novelty is thus: the ASU can be used to absorb the energy storage air to maximize the air utilization and improve the energy efficiency of the integrated system. It can be simulated using Aspen Plus software. Based on the simulated data, an optimal process flow is determined by analyzing the effect of a reduction in discharge of energy storage air on the distillation conditions of the ASU, and its energy efficiency analysis and economic evaluation are conducted. When the discharge of energy storage air is reduced by 50 % during energy storage and the stored liquid air is directly recovered into the ASU during energy release, a proposed process flow with largest absorption for energy storage air could be obtained. Its product exergy efficiencies for energy storage and release are 37.80 % and 37.57 %, respectively. The overall exergy efficiency of the LAES and the electrical round-trip efficiency of the proposed system are both 67.48 %, the electricity cost saving ratio is 6.43 %, and the payback period of the LAES is 2.4 years. The investment in an air booster accounts for the largest proportion of the overall cost (being some 49.3 % of the total investment required for such a LAES system). After the proposed system is applied throughout the industry, carbon dioxide emissions can be decreased by 15.12–26.76 Mt/year on the grid side.