化学链燃烧铜基载氧体前驱体煅烧反应热力学研究

Thermodynamic Study of Calcination Reaction of Copper-Based Oxygen Carrier Precursor in Chemical Looping Combustion

基于吉布斯最小自由能原理,对铜基载氧体前驱体燃烧合成过程进行平衡模拟计算。预测了固体产物状态和气体产物分布。通过改变原料配比,计算绝热燃烧温度,判断反应能否自我维持。结果表明,在加入物料为化学计量比的反应条件下,平衡绝热燃烧温度T_(ad)为2300~2400℃,燃烧能自我维持。在加入物料为非化学计量比,尿素小于0.2倍理论加入量时,该燃烧不能自我维持,尿素小于0.5理论加入量时,含Cu化合物以液相形式存在。该体系中NO是NO_(x)的主要成分,随着尿素的增加,NO含量先快速增加后减少,当尿素占比为0.71时,NO含量达到极值。过量尿素的加入会使NO还原为N_(2)。

Based on principle of minimum Gibbs free energy,the combustion synthesis process of copper oxygen carrier precursor was simulated.Solid product states and gas product distributions were predicted.The adiabatic combustion temperature was calculated by changing the ratio of raw materials to determine whether the reaction was self-sustaining.The results showed that the temperature of balanced adiabatic combustion was 2300-2400℃and the combustion was maintained by itself under the condition of chemical stoichiometric ratio.When the material was non-stoichiometric and urea was less than 0.2 times of the theoretical amount,the combustion was not self-sustained.When urea was less than 0.5 times of the theoretical amount,Cu-containing compounds existed in liquid form.NO was the main component of NO_(x) in the system,which increased rapidly at first and then decreased with the increase of urea.When the proportion of urea was 0.71,the amount of NO reached the extreme value.The addition of excess urea can reduce NO to N_(2).