Abstract Flux, able to improve the ash fusibility, usually contains catalytic metal compounds. Unfortunately, the quantitative analysis of synergistic catalysis effects between different fluxing agents on coal gasification has not been investigated thoroughly. In this study, the effect of the kinds and content of Na/Ca-based fluxes on char gasification was investigated in thermogravimetry analyzer (TGA). The synergistic catalysis effects and mechanism between the two kinds of fluxes were also studied. Finally, based on the TGA tests, the kinetics models for char gasification with flux addition were developed. The results showed that all the four Na-based fluxes could increase the char reactivity. Na2CO3, which afforded the best activity, could increase the reactivity by 5.3 times when the content was 5%. The five Ca-based fluxes had a weaker catalysis effect compared with Na-based fluxes. CaCl2, exhibiting the best activity among the five Ca-based fluxes, could increase the reactivity by 2.3 times when the content was 5%. For composite fluxes, Na2CO3–CaO and Na2CO3–CaCO3 had a remarkable synergistic effect, whereas others had less effect. Na2CO3 could inhibit the aggregation of Ca, which might cause the synergistic effects between Na and Ca fluxes. The random pore model was more suitable to describe the catalytic gasification process.

中文翻译：

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Na/Ca基助熔剂对煤焦气化的催化性能

摘要 助熔剂通常含有催化性金属化合物，能提高灰的熔融性。不幸的是，尚未彻底研究不同助熔剂对煤气化的协同催化作用的定量分析。本研究采用热重分析仪 (TGA) 研究了 Na/Ca 基助熔剂的种类和含量对炭气化的影响。还研究了两种助熔剂之间的协同催化作用和机理。最后，基于 TGA 测试，开发了添加助熔剂的焦炭气化动力学模型。结果表明，四种钠基助熔剂均能提高炭反应性。活性最好的Na2CO3含量为5%时，反应性提高5.3倍。与钠基熔剂相比，五种钙基熔剂的催化效果较弱。在五种钙基助熔剂中，CaCl2 表现出最好的活性，当含量为 5% 时，反应性可提高 2.3 倍。对于复合助焊剂，Na2CO3-CaO 和 Na2CO3-CaCO3 具有显着的协同作用，而其他的作用较小。Na2CO3 可以抑制 Ca 的聚集，这可能导致 Na 和 Ca 通量之间的协同作用。随机孔模型更适合描述催化气化过程。Na2CO3 可以抑制 Ca 的聚集，这可能导致 Na 和 Ca 通量之间的协同作用。随机孔模型更适合描述催化气化过程。Na2CO3 可以抑制 Ca 的聚集，这可能导致 Na 和 Ca 通量之间的协同作用。随机孔模型更适合描述催化气化过程。