A system and method for increasing the efficiency and/or power produced by an integrated gasification combined cycle system by increasing the integration between the air separation unit island, the heat recovery steam generator and the remainder of the system. By integrating heat produced by the heat recovery steam generator in the remainder of the integrated gasification combined cycle system, heat may be utilized that may have otherwise been lost or used further downstream in the system. The integration helps to increase the efficiency of the combustion reaction and/or the gasification reaction used to produce the syngas utilized in the integrated gasification combined cycle system.