Can Steam- and CO-Rich Streams Be Produced Sequentially in the Isothermal Chemical Looping Super-Dry Reforming Scheme?

[Image: see text] Super-dry reforming of methane (CH(4) + 3CO(2) → 2H(2)O + 4CO) is a very promising route for CO(2) utilization. To maximize the yield of CO, a water–gas shift reaction (CO + H(2)O → CO(2) + H(2)) should be circumvented. Combination of dry reforming of methane, redox reactions (metal oxide is reduced by CO and H(2) in one step and then oxidized by CO(2) in the next step), and CO(2) sorption in a fixed-bed reactor was proposed as a potential approach to suppress the water–gas shift reaction. It was demonstrated that this isothermal operation can produce two separate streams, one is rich in steam and the other in CO, in a redox cycle at 750 °C. However, both the thermodynamic analysis and experimental investigations suggest that steam- and CO-rich streams may not be produced sequentially in the redox mode at 750 °C.