이산화탄소 분리를 위한 씰린더형 전기화학적 막의 제조 및 분리 특성

Abstract

A cylindrical-shape electrochemical separation membrane was prepared using porous α-alumina. The electrodes were coated with NiO on both sides of the cylindrical-shape matrix by a dipping method. A mixture of Li₂CO₃/K₂CO₃(=62/ 38 molar ratio) was used as the electrolyte which was heated at 620 ℃ to be liquified and impregnated into the pores of the NiO-coated membrane. The prepared electrochemical membrane, which was operated at 620-650℃, was applied to the separation of CO₂ from a gas mixture(CO₂/O₂/N₂=0.25/0.16/0.59, molar ratio) and tested the effects of the current density on the permeability and concentration of carbon dioxide in the permeate, and the current efficiency. The permeability of carbon dioxide was increased monotonically with increasing the current density. The carbon dioxide was concentrated from 25% to 70% when increasing the current density. The current efficiency was decreased with increasing the current density. The prepared electrochemical membrane had the separation efficiency of 90.3%. In this work, it was proved that the cylindrical-shape electrochemical membrane prepared by using the porous inorganic membrane could be applied to the CO₂ separation from a gas mixture. However, the high overall resistance through the EMSD remains as a challenging problem.