(4aa) Chemical Looping Strategy and Its Commercial Potential for Carbon Negative Energy Conversions

Energy and global warming are two intertwined issues of critical importance in the modern era. With the pressing needs for clean, efficient, and cost effective energy sources, the chemical looping strategy has evolved as a promising alternative to the traditional carbonaceous fuel conversion processes. With aid of oxygen carrier particles, the chemical looping process efficiently converts carbonaceous fuel while capturing CO₂ in an effective manner by looping reaction design. Two unique chemical looping gasification processes, i.e. the Syngas Chemical Looping (SCL) and the Coal/Biomass Direct Chemical Looping (CDCL) processes were developed and investigated. Unlike other chemical looping processes that are combustion based, the SCL and CDCL processes convert a variety of fuels including coal and biomass into a combination of hydrogen, liquid fuel, and/or electricity. Over the past 6 years, the processes have been advanced from a novel concept to successful sub-pilot (25 kW_th) scale demonstrations. A 250 kW_th SCL pilot plant is being designed and will be operated at the National Carbon Capture Center (NCCC). The various aspects of the looping process development including the formulation and performance of the oxygen carrier particles, the bench and sub-pilot scale process testing results, and the energy integration optimization and techno-economic analyses of the processes will be presented. The scale-up strategy of the processes for commercial use will also be discussed. The ionic transfer mechanism that underlines the oxygen carrier reaction along with several energetically optimized novel applications of the chemical looping for gasification process systems will be highlighted.