选择性催化还原烟气脱硝过程数学模拟研究

Mathematical Simulation Study of a Selective Catalytic-reduction-based Flue-gas Denitration Process

SCR烟气脱硝反应过程数学模型是催化反应器设计、运行控制的基础。进行了SCR烟气脱硝反应的实验研究,考察了有关参数对脱硝性能的影响,获得了脱硝性能与这些参数之间关系的定量数据;根据SCR烟气脱硝反应过程的有关机理,建立了SCR烟气脱硝反应过程的数学模型,该模型采用Eley-Rideal机理模型作为催化剂表面反应动力学模型,并考虑了催化剂壁内的传质。对利用SCR烟气脱硝宏观反应数据推算模型中的化学反应动力学参数的方法进行了研究,用小型实验数据推算了模型中的化学反应动力学参数。数学模型采用有限差分法求取数值解,数值模拟结果与实验结果符合良好,说明模型是合理的。

The mathematical models for SCR(selective catalytic reduction) flue-gas denitration reaction process can provide a basis for the design,operation and control of catalytic reactors.An experimental study was performed of the SCR flue-gas denitration reaction process along with an investigation of the influence of relevant parameters on the denitration performance.The data showing the relationship between the denitration performance and these parameters have been obtained.On the basis of the relevant mechanism of SCR flue-gas denitration reaction process,a mathematical model for such a reaction process was set up and the Eley-Rideal mechanism model quantitatively used as the surface reaction dynamic model of a catalyst with due consideration of the in-wall mass transfer of the catalyst.The method for the calculation of chemical-reaction dynamic parameters in the model by use of SCR flue-gas denitration macro reaction data was studied and the above-mentioned parameters were computed by utilizing the data from small-scale tests.The numerical solutions to the mathematical model were sought by employing the finite difference method.The numerical simulation results are in good agreement with the test ones,thus indicating that the model is rational.