Reactor and technical feasibility aspects of a CO₂ decomposition-based power generation cycle, utilizing a high-temperature membrane reactor

The technical feasibility of separating and decomposing CO₂ in the context of a novel energy generation cycle during the operation of a glass furnace was investigated. The concept envisions CO₂ decomposition to take place in a membrane reactor utilizing high-temperature solid-oxide membranes with the aid of oxygen chemical pumping. The glass furnace environment is well suited for such an application because it provides the high-temperature conditions needed for the operation of these membranes. As part of this effort, solid-oxide membranes were prepared and their oxygen permeation was measured in a membrane reactor system. The O₂ permeabilities in the presence of a reactive sweep were significantly higher than the corresponding permeabilities measured in the presence of He as a sweep gas. These membranes were utilized for CO₂ decomposition in a membrane reactor. Conversions significantly higher than the expected thermodynamic equilibrium values were attained. Engineering calculations of the overall glass furnace efficiency were also carried out, and the conditions for optimal performance were determined. The effects of the application of this novel cycle on glass furnace operation in terms of combustion stability (quantified by the extinction strain rates of the relevant combustion mixtures) and pollutant (NO_x) emissions were also determined. Generally, improvements in combustion intensity and stability can be achieved but at a cost of increased NO_x emissions and vice versa. A range of conditions also exists for which the cycle allows for effective waste heat utilization without undue impact on pollutant emissions.