Study of the countercurrent-concurrent gas-liquid flow configuration impact on ethylene hydrogenation within structured catalyst bed: Experiment and modeling

In this paper catalytic hydrogenation of ethylene was studied using liquid propane with 1.5% of ethylene content and hydrogen gas in 30 barg trickle bed reactor under two flow configurations: countercurrent and concurrent. Trickle bed experiments were then performed using an experimental package comprising high pressure pilot reactor, gas chromatograph apparatus, dosing pump and required instrumentation system to compare countercurrent and concurrent sampled data furthermore structured catalyst of alumina-nickel was used as catalytic bed. Trickle bed modeling was achieved using a package of 12 dimensionless two-dimensional homogeneous mass and momentum transfer partial differential equations, the model parameters and kinetic equations. Orthogonal collocation technique was employed to solve developed PDEs. Predicted performance of the trickle bed by mathematical modeling was compared by experimental results and there was good consistency between them. The experimental results showed zero concentration of ethylene through countercurrent flow. Finally, the experimental analysis reports emphasize on zero concentration of ethylene in output of countercurrent bed whilst increasing the Reynolds number did not conclude to nil concentration of ethylene in output of concurrent bed. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.