Modelling of a Catalyst Pellet with Non-Uniform Activity Distribution in Fischer-Tropsch Synthesis

فاقد چكيده

Modeling of a catalyst pellet for Fischer-Tropsch Synthesis (FTS) was studied in this work. Under FTS conditions the pores of catalyst pellet are filled with liquid hydrocarbons leading to transport restrictions through the pellet. On the other hand, the active materials used as catalysts are often expensive metals dispersed on large-surface area supports in order to be utilized effectively. To overcome these problems and to improve catalyst performance parameters such as the yield of C5 +, modeling of catalyst in various types of non-uniform activity distributions were considered. These include general non-uniform catalysts (egg-shell, egg-yolk, and egg-white), Dirac-δ, and layered catalysts (surface-layered, center-layered, and mid-layered). The models were solved by OCFE (Orthogonal Collocation on Finite Elements) method in non-isothermal conditions. Moreover, a parametric sensitivity analysis has been carried out to compare the effects of various non-uniform distribution functions, different pellet sizes, feed composition, temperature and pressure on the performance of the catalyst.