Abstract:

The BaFe₂O₄ oxygen carrier and BaFe₂O₄ oxygen carrier modified by Ni, Ce and K were prepared by the sol-gel method, and the best oxygen carrier was selected as 10%(mass) K modified BaFe₂O₄ (10K-BF), and the difference was explored. The effect of reaction conditions on its performance was characterized by H₂-TPR, XRD, SEM, and BET on the oxygen carrier. The experimental results showed that the addition of Ni, Ce and K all increase the syngas yield. The 10K-BF oxygen carrier exhibited the best performance when the mass ratio of steam to biomass (S/B) was equal to 3, peroxygen coefficient α=0.20 and t=800℃. Its syngas yield was 1.864 m³/(kg Biomass), hydrogen production rate was 1.038 m³/(kg Biomass), carbon conversion rate was 90.49% and carbon deposition rate was 1.33%. After 10 cycles, there was still a high syngas yield and carbon conversion rate. H₂-TPR result indicated that the 10K-BF oxygen carrier starts to release oxygen at 300°C and can participate in the reaction at the initial stage of biomass pyrolysis, which is beneficial to the cracking of tar. XRD characterization showed that the 10K-BF oxygen carrier can recover part of the spinel structure after regeneration.

Key words: biomass, gasification, syngas, carbon deposition rate, barium ferrite

摘要：

以溶胶凝胶法制备了BaFe₂O₄载氧体以及Ni、Ce、K修饰的BaFe₂O₄载氧体，筛选出最佳载氧体为10%(质量)K修饰的BaFe₂O₄载氧体(10K-BF)，探究了不同反应条件对其性能的影响，通过H₂-TPR、XRD、SEM、BET对载氧体表征。实验结果表明，Ni、Ce、K的添加均提高了载氧体的合成气产率，10K-BF载氧体在水蒸气与生物质质量比(S/B)等于3，过氧系数α=0.20，反应温度800℃时，气化效果最好，合成气产率1.864 m³/(kg Biomass)，氢气产率1.038 m³/(kg Biomass)，碳转化率90.49%，积炭率1.33%，10次循环后仍有较高的气体产率及碳转化率。H₂-TPR表明10K-BF载氧体在300℃开始释氧，在生物质热解的初始阶段即可参与反应，有利于焦油的裂解；XRD表明10K-BF载氧体再生后可以恢复部分尖晶石结构。

关键词: 生物质, 气化, 合成气, 积炭率, 铁酸钡