Modeling Kinetic, Thermodynamic, and Operational Effects in a Steam Methane Reformer. Part A: Reformer Output

Abstract

Key decisions in developing a model of a steam methane reformer were investigated in this paper. A comprehensive one-dimensional Python model of a reformer tube is proposed, including the effects of sintering and poisoning. Comparison between the Redlich−Kwong and ideal gas equations of state shows little difference upon reformed gas outlet properties. Different reaction kinetic models are tested over a variety of realistic conditions and compared against industrial data. Overall, these changes only impact conditions near the reactor inlet, as the approach to thermodynamic equilibrium near the reactor outlet ensures that all model-predicted process variables at the outlet are similar. Models from both Xu and Froment and Hou and Hughes are recommended for future reformer models where accurate outlet variables are required.

Modeling Kinetic, Thermodynamic, and Operational Effects in a Steam Methane Reformer. Part B: Carbon Formation

“…Here, a range of industrial conditions were used as discussed in the preceding work. 1 Clearly, all reaction models do not predict WGS activity accurately and underpredict CO/CO 2 ratio. This indicates that high temperature WGS activity predicted with the studied models is inaccurate.…”

“…In a separate publication, a comprehensive one-dimensional model of the tube side of the reformer was developed. 1 Here, this model and its results will be utilized to predict the locations of carbon formation within the reformer tube. The effect of process gas composition will be analyzed in its ability to reduce carbon formation.…”

“…A key assumption made is that coking kinetics developed for this catalyst are applicable to all supported nickel catalysts and that these coking kinetics can be applied to all reforming kinetics studied in the preceding work. 1 Equations 7 and 8 are the forward reactions of reactions 1 and 2, respectively. Equations 9−11 are the reverse reactions of reactions 1−3, respectively.…”

“…The temperature, pressure, and component flow rate profiles generated by executing the model are shown in the initial paper. 1 To assist with subsequent explanations in this work, the component profiles along the length of the reformer are shown in Figure 1.…”

“…Accounting for these real gas effects of the process, gas within a single reformer tube showed minimal differences at the outlet. 1 The net rate of coke formation is compared between the Redlich−Kwong (RK) and IG equations of state and is shown in Figure 7.…”