An Advanced Cryogenic Air Separation Process for Integrated Gasification Combined Cycle (IGCC) Systems

An advanced cryogenic air separation unit (ASU) process for integrated gasification combined cycle (IGCC) system is proposed based on self-heat recuperation technology. In the proposed ASU process, only one distillation column was used in contrast to double columns in the conventional ASU process. The N2 product gas from the top of the distillation column is first compressed, and then exchange heat with the air liquid from the bottom using the self-heat recuperation technology. Thus, both the latent heat and the sensible heat of the N2 product steam are circulated, resulting in a significant reduction of energy consumption in cryogenic ASU process. In addition, the exergy destruction of the compressors, which contributes to the largest part in previous study, is significantly reduced as no high-pressure column is used in the proposed process. The simulation results show that the total energy consumption of the proposed cryogenic air separation process is reduced by around 30 % compared with the conventional cryogenic air separation process for IGCC systems.