中文摘要：

以煤制天然气为背景，研究了反应器高径比、进料温度、操作压力、空速、原料气组成对高温甲烷化反应器内部温度和浓度分布的影响。通过建立固定床反应器拟均相二维模型，模拟合成气完全甲烷化过程，采用MATLAB进行数值求解，并与工业侧线试验数据进行对比。结果表明，高径比为2～3时有助于减小热损，可以控制床层热点温度在700℃以下；进料温度升高到400℃，加快了反应速率，导致热点温度过高，接近800℃；操作压力不适宜，直接影响CO的加氢效果；空速由4000提高到16000h^-1时，床层热点显著向反应器出口移动：原料气氢碳HS（H2／（3CO＋4CO2））增大到2，促进CO转化，而水气比由0．19增加到0．4，可以有效控制床层温升，热点温度在650℃左右。相关研究结果为反应器设计和工艺参数的优化提供了依据。

英文摘要：

The effects of bed aspect ratio, inlet feed temperature, operating pressure, space velocity and feed composition on temperature and concentration distributions in a methanation reactor were studied using coal-to-SNG （Synthetic Natural Gas） as a model process. A two-dimensional pseudo-homogeneous model was established to simulate the fixed bed methanation reactor. The numerical model was solved by MATLAB code and validated by comparing the numerical results with experimental data obtained from an industrial side-stream test. Results show that a bed aspect ratio of 2-3 is helpful to reduce heat loss and keep the hot spot below 7000C. A feed temperature of 400~C can accelerate reaction rate and lead to a higher bed temperature of-800℃. The CO hydrogenation process is directly affected by operating pressure. The location of the hot spot moves towards the reactor outlet as the space velocity rises from 4000 to 16000 h^-1. When the hydrogen-to-carbon ratio （defined as H2/（3CO＋4CO2）） in the feed increases to 2, the CO conversion can be promoted. An increase of the steam-to-gas ratio from 0.19 to 0.4 can effectively control adiabatic temperature with a hot spot temperature of- 650℃.