Zhu Xiao, Zhang Jiang, Yan Jingchun, Shen Laihong
Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China.
ACS Omega. 2021 Feb 8;6(7):4783-4792. doi: 10.1021/acsomega.0c05691. eCollection 2021 Feb 23.
Chemical looping gasification (CLG) has been described as an innovative and low-cost gasification technology to convert carbonaceous fuels into synthesis gases. Oxygen carrier (OC) is the key to resolve the contradiction between rapid carbon conversion and appropriate partial oxidation of coal. At present, the solid fuel conversion in the CLG process is limited by an iron-based OC, and a copper-based carrier has difficulty in maintaining the reduction atmosphere. Hence, CuFeO has been proposed as a high-performance OC because of its synergistic effect. The present study first conducted a characteristic evaluation on CuFeO, including the reducibility and oxygen release capacity. The results showed that the addition of copper made a great contribution to the reduction process, and the presence of ferrite better relieved the deep oxygen loss of CuFeO. The thermodynamic limitation and evolution behavior of CuFeO in the reduction process were discussed for the simulation. An Aspen model of the CLG process with coal as the fuel and CuFeO as the OC was then established and validated by the experimental data. By consideration of the high carbon conversion and high syngas productivity in the operation, an OC/fuel mass ratio of approximately 1.25-2.25 and a gasification temperature range of 800-900 °C were thought to be optimal in the coal CLG process.
化学链气化（CLG）已被描述为一种创新的低成本气化技术，可将含碳燃料转化为合成气。氧载体（OC）是解决煤炭快速碳转化与适度部分氧化之间矛盾的关键。目前，CLG过程中的固体燃料转化受到铁基OC的限制，而铜基载体难以维持还原气氛。因此，由于其协同效应，CuFeO被提议作为一种高性能的OC。本研究首先对CuFeO进行了特性评估，包括还原性和氧释放能力。结果表明，铜的添加对还原过程有很大贡献，铁素体的存在更好地缓解了CuFeO的深度氧损失。通过模拟讨论了CuFeO在还原过程中的热力学限制和演变行为。然后建立了以煤为燃料、CuFeO为OC的CLG过程的Aspen模型，并通过实验数据进行了验证。考虑到运行中的高碳转化率和高合成气生产率，在煤炭CLG过程中，OC/燃料质量比约为1.25 - 2.25以及气化温度范围为800 - 900°C被认为是最佳的。
