Coal Refining Chemical Looping Systems with CO2 as a Co-Feedstock for Chemical Syntheses

This study quantifies the advantages of a chemical looping reducer reactor modularization strategy that leverages two or more reducer reactors operating in parallel to enhance syngas production beyond what is achievable by a single reducer reactor or conventional processes. The modularized system incorporates CO2 capture and utilization as a feedstock in an iron-titanium composite metal oxide based chemical looping system to enhance coal based chemical production. Simulations conducted in ASPEN Plus software suggest that adopting a cocurrent moving bed reducer reactor based modularization strategy can improve syngas yield by greater than 11% over a single chemical looping reducer reactor. Experiments conducted on a bench scale reducer reactor confirm the findings of the simulations. The modularization simulation was scaled up and incorporated into commercial sized methanol and acetic acid production plants. Chemical looping modularization demonstrates the ability to reduce coal consumption by 25% over a baseline coal gasification process, compared to 15% reduction if a single chemical looping reducer reactor is used instead of the modular strategy, for 10 000 ton per day methanol production. Integration into a commercial scale acetic acid plant shows conditions in which the process can operate as a CO2 neutral or negative system, where the process was consuming more CO2 than it produces. These results indicate the potential for significant feedstock reduction in large-scale coal to chemical processes, like methanol, acetic acid, formic acid, and oxalic acid.