Chemical looping gasification (CLG) is a novel technology using lattice oxygen in a solid oxygen carrier (OC) for syngas production. The present work investigated the CLG performance of coal in a 5 kW_th interconnected fluidized bed, in which the fuel reactor was designed as a two-stage-based circulating bed. The fresh OC from the air reactor entered into the upper stage of the fuel reactor, in which it was reduced by syngas. Then, the partial reduction of the OC was circulated to the bottom stage of the fuel reactor to be reduced further to low-valence metal oxide and catalyze the process of coal gasification. Afterward, the reduced OC was transported to the air reactor for regeneration. The influences of the coal feeding rate, gasification temperature, and gasification agent on the performance of CLG were evaluated in detail. The syngas yield and gasification efficiency were remarkably influenced by the coal feeding rate, with an optimal value of 487.5 g/h in the current unit. The high temperature promoted the coal gasification process with the maximum gasification efficiency and syngas yield corresponding to 75.2% and 0.97 Nm³ kg^–1 of coal, respectively, at a gasification temperature of 915 °C. Steam, CO₂, and a mixture of them were used as gasifying agents separately. The experimental results demonstrated that carbon conversion, syngas yield, and gasification efficiency increased with the proportion of steam in the gasifying agent. The OC particles in the upper and bottom stages of the fuel reactor were analyzed by X-ray diffraction. The main phase of the OC particles in the bottom stage was FeO, which has a high catalytic activity on coal gasification and tar cracking. Serious particle agglomeration was observed under the low fluidization flow of 20 L/min and high temperature of 950 °C at which the system cannot be stably operated.

中文翻译：

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煤的化学链气化在5千瓦_个互联流化床用两阶段燃料反应器床

化学回路气化（CLG）是一种使用固体氧载体（OC）中的晶格氧来生产合成气的新技术。本工作研究了5 kW _th的煤的CLG性能相互连接的流化床，其中燃料反应器设计为两级循环床。来自空气反应器的新鲜OC进入燃料反应器的上级，并在其中被合成气还原。然后，将OC的部分还原循环到燃料反应器的底部，以进一步还原为低价金属氧化物并催化煤气化过程。之后，将还原的OC输送到空气反应器中进行再生。详细评估了给煤速率，气化温度和气化剂对CLG性能的影响。进煤速度显着影响合成气的产率和气化效率，当前单位的最佳值为487.5 g / h。在915°C的气化温度下分别为³ kg ^–1的煤。蒸汽，CO ₂和它们的混合物分别用作气化剂。实验结果表明，随着气化剂中蒸汽的比例，碳的转化率，合成气的产率和气化效率均增加。通过X射线衍射分析燃料反应器的上级和下级中的OC颗粒。底部的OC颗粒的主要相是FeO，它对煤气化和焦油裂解具有很高的催化活性。在20 L / min的低流化流量和950°C的高温下观察到严重的颗粒团聚，在该温度下系统无法稳定运行。