Chemical looping combustion (CLC) is a promising technology paving the way for the inherent CO₂ capture. As Indian coals are enriched in ash content (with 40%), their utilization in the CLC technology under direct fueled condition is challenging due to the ash layer resistance in the reactivity of metal oxides. Alternatively, the blending of biomass with high ash coal (HAC) can enhance fuel reactivity with metal oxides. In this context, the present study is focused on the co-utilization of high ash Indian coal (ash 33 wt %) and rice straw (RS) in the CLC process using Fe₂O₃ particles as metal oxides in a fixed bed reactor under CO₂ based in-situ gasification mode of operation. The intrinsic reactivity of ash, char, and volatile matter of the solid fuels with Fe₂O₃ is assessed individually. The obtained CLC based experimental results showed that the CO₂ capture efficiency and gas conversion are found to be increased by 9.7% and 6%, respectively, during the co-utilization of HAC and RS. The reactivity of H₂, CO, and CH₄ with Fe₂O₃ is also assessed under the co-combustion mode of the CLC process. The XRD results showed that the formation of calcium ferrite (CaFe₂O₄) had enhanced the conversion of char during the CLC process. A higher reactivity between char and Fe₂O₃ (solid-solid interaction) is observed at high operating temperatures with 13% increase in the weight loss under the co-combustion mode of the CLC process. Further, the kinetic parameters are evaluated for the CLC and non-CLC based reactions under various operating temperature regimes. Among the kinetic models considered, the shrinking core model is found to be the best fit, compared to the homogenous progression model. The chemical reaction is the slowest step at the operating temperatures in the range of 200–500 °C; ash layer diffusion is found as the rate controlling step at high operating temperatures (800–1000 °C); whereas film diffusion controlled mechanism is dominant at 700–800 °C.

化学循环燃烧（CLC）是一种有前途的技术，为固有的CO ₂捕集铺平了道路。由于印度煤炭的灰分含量丰富（达40％），由于在金属氧化物反应性中的抗灰层性，在直接燃料条件下将其用于CLC技术具有挑战性。备选地，生物质与高灰分煤（HAC）的掺混可以增强燃料与金属氧化物的反应性。在这种情况下，本研究的重点是在固定床反应器中，使用Fe ₂ O ₃颗粒作为金属氧化物，在CLC工艺中高灰分印度煤（灰分33 wt％）和稻草（RS）的联合利用。一氧化碳₂基于原位气化的操作模式。分别评估固体燃料与Fe ₂ O ₃的灰分，炭和挥发性物质的固有反应性。获得的基于CLC的实验结果表明，在HAC和RS的联合利用过程中，CO _2的捕集效率和气体转化率分别提高了9.7％和6％。H ₂，CO和CH ₄与Fe ₂ O ₃的反应性也在CLC工艺的共燃烧模式下进行了评估。XRD结果表明，铁酸钙（CaFe ₂ O ₄）在CLC过程中增强了char的转换。炭和Fe ₂ O ₃之间的反应性更高（固-固相互作用）在高工作温度下观察到，在CLC工艺的共燃烧模式下，失重增加了13％。此外，在各种操作温度范围内，对基于CLC和非CLC的反应的动力学参数进行了评估。在考虑的动力学模型中，与同质进行模型相比，收缩核心模型被认为是最合适的。在200-500°C的工作温度下，化学反应是最慢的步骤；在高工作温度（800–1000°C）下灰分扩散是速率控制的步骤；而薄膜扩散控制机制在700–800°C时占主导地位。