氧气高炉循环煤气加热过程中的析碳行为

以氧气高炉循环煤气加热工艺为背景，在实验室条件下研究了CO和H₂体积分数较高的煤气加热时的析碳行为。实验结果表明，温度和CO₂体积分数是影响析碳反应的重要因素。在300-700℃范围内，当温度低于500℃时，析碳反应速度随温度的升高而增加；当高于此温度时，反应速度随温度的升高而下降。析碳反应包括CO分解析碳反应以及CO和H₂的混合析碳反应。对比热力学理论与实验现象分析了析碳过程中以上两个反应可能起到的作用。采用扫描电镜，从微观结构上观察了500~700℃时加热过程中析出碳的形态并研究了析碳行为。另外，随着CO₂体积分数的增加，析碳反应速率逐渐降低。在500℃和600℃时，CO₂体积分数的增加对析碳行为有较大抑制作用，尤其在500℃时这种抑制作用更加明显。

Carbon deposition reaction based on heating recycling gas of oxygen blast furnaces

Taking the heating process of recycling-gas for oxygen blast furnaces as a research background, carbon deposition behavior in heating at higher CO and H₂ volume fractions was investigated under a laboratory condition. The results indicate that temperature and CO₂ volume fraction are important factors for carbon deposition. In the temperature range of 300℃ to 700℃, the carbon deposition rate increases with the increase of temperature below 500℃, but deceases when above 500℃. The carbon deposition includes CO decomposition and carbon deposition reaction by the hybrid of CO and H₂, each possible role of which was analyzed through comparing the thermodynamic theory and experimental phenomena in the carbon deposition. The morphology of deposited carbon and the carbon deposition behavior in heating from 500℃ to 700℃ were investigated by scanning electron microscopy. In addition, the carbon deposition rate decreases gradually with the increasing of CO₂ volume fraction at 500℃ and 600℃, and this inhibition effect on the carbon deposition behavior is greater at 500℃.