Carbon dioxide separation and recovery method based on low-temperature distillation technology

Abstract

The invention belongs to the technical field of carbon capture and storage, and particularly relates to a carbon dioxide separation and recovery method based on a low-temperature distillation technology, which comprises the following steps: introducing industrial waste gas containing carbon dioxide into a pretreatment unit, and removing particulate matters, moisture and acid gas impurities in the industrial waste gas; the pretreated waste gas enters a cooling system, so that part of high-boiling-point gas components are liquefied and separated; the cooled mixed gas enters a low-temperature distillation tower for rectification separation; collecting a liquid-state or supercritical-state high-purity carbon dioxide product at the bottom of the low-temperature distillation tower, wherein the purity is not lower than 99%; uncondensed light component gas is discharged from the tower top, and is discharged or further treated after cold energy is recovered through a heat exchanger; according to the invention, high-efficiency separation and high-purity recovery of carbon dioxide are realized; a multi-stage cooling and cold energy recovery system is adopted, so that the overall energy consumption is obviously reduced; the system adopts a modular design, is convenient to integrate and expand, and is suitable for various industrial scenes.

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