Energy-Saving CO₂Capture by H₂Gas Stripping for Integrating CO₂Separation and Conversion Processes

CO2 capture and utilization technology, such as converting CO2 to fuel or chemicals by renewable energy-derived H2, has been promoted for recent decades. Herein, a process is proposed that saves considerable amounts of energy by integrating the CO2 separation and conversion processes. In the case of the method of amine absorption, supplying H2 to the bottom of the desorber reduces the regeneration temperature, which can reduce the process exergy. If combined with reaction heat recovery using a heat pump system, a considerable amount of energy can be saved. The recovered mixture of CO2 and H2 gas is then used directly as a raw reaction material. Herein, the proposed stripping regeneration process is compared on theoretical and equilibrium bases, with the conventional monoethanolamine method and the phase-separation solvent method developed by the authors. Using the phase-separation solvent leads to lower energy in the stripping regeneration.