Abanades Stéphane, Wang Xinhe, Chuayboon Srirat
CNRS, Processes, Materials and Solar Energy Laboratory (PROMES-CNRS), 7 Rue du Four Solaire, 66120 Font-Romeu, France.
State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Molecules. 2025 Feb 26;30(5):1076. doi: 10.3390/molecules30051076.
The chemical looping reforming of methane using an SrFeO oxygen carrier to produce synthesis gas from solar energy was experimentally investigated and validated. High-temperature solar heat was used to provide the reaction enthalpy, and therefore the methane feedstock was entirely dedicated to producing syngas. The two-step isothermal process encompassed partial perovskite reduction with methane (partial oxidation of CH) and exothermic oxidation of SrFeO with CO or HO splitting under the same operating temperature. The oxygen carrier material was shaped in the form of a reticulated porous foam structure for enhancing heat and mass transfer, and it was cycled in a solar-heated tubular reactor under different operating parameters (temperature: 950-1050 °C, methane mole fraction: 5-30%, and type of oxidant gas: HO vs. CO). This study aimed to assess the fuel production capacity of the two-step process and to demonstrate the potential of using strontium ferrite perovskite during solar cycling for the first time. The maximum H and CO production rates during CH-induced reduction were 70 and 25 mL/min at 1000 °C and 15% CH mole fraction. The increase in both the cycle temperature and the methane mole fraction promoted the reduction step, thereby enhancing syngas yields up to 569 mL/g during reduction at 1000 °C under 30% CH (778 mL/g including both cycle steps), and thus outperforming the performance of the benchmark ceria material. In contrast, the oxidation step was not significantly affected by the experimental conditions and the material's redox performance was weakly dependent on the nature of the oxidizing gas. The syngas yield remained above 200 mL/g during the oxidation step either with HO or CO. Twelve successive redox cycles with stable patterns in the syngas production yields validated material stability. Combining concentrated solar energy and chemical looping reforming was shown to be a promising and sustainable pathway toward carbon-neutral solar fuels.
利用锶铁氧体氧载体对甲烷进行化学链重整以利用太阳能生产合成气，进行了实验研究和验证。高温太阳能用于提供反应焓，因此甲烷原料完全用于生产合成气。两步等温过程包括甲烷对钙钛矿的部分还原（CH的部分氧化）以及在相同操作温度下用CO或H₂O分解对SrFeO进行的放热氧化。氧载体材料成型为网状多孔泡沫结构以增强传热和传质，并在太阳能加热的管式反应器中在不同操作参数（温度：950 - 1050℃，甲烷摩尔分数：5 - 30%，以及氧化气体类型：H₂O与CO）下循环。本研究旨在评估两步法的燃料生产能力，并首次证明在太阳能循环过程中使用锶铁氧体钙钛矿的潜力。在CH诱导还原过程中，在1000℃和15% CH摩尔分数下，H₂和CO的最大生产率分别为70和25 mL/min。循环温度和甲烷摩尔分数的增加均促进了还原步骤，从而在1000℃、30% CH还原过程中使合成气产率提高至569 mL/g（包括两个循环步骤则为778 mL/g），因此优于基准氧化铈材料的性能。相比之下，氧化步骤受实验条件的影响不显著，且材料的氧化还原性能对氧化气体的性质依赖性较弱。无论是使用H₂O还是CO，在氧化步骤中合成气产率均保持在200 mL/g以上。合成气产率具有稳定模式的十二次连续氧化还原循环验证了材料的稳定性。将聚光太阳能与化学链重整相结合被证明是一条通往碳中和太阳能燃料的有前景且可持续的途径。
