HYDRODYNAMICS BEHAVIOUR OF SIMULATION OF ONE-STEP UREA SYNTHESIS IN MICROREACTOR

Urea or Carbamide (NH2CONH2) functioned as nitrogen-rich fertilizers which is vital to the agriculture industry. Currently, the Urea synthesis involving two step conversions process; the initial steps are ammonia production through Haber - Bosch process through the reaction of Hydrogen (H2) and Nitrogen (N2) Gas in high temperature and pressure with the presence of Iron Oxide (Fe2O3) as the catalyst. The second step composed of reaction between ammonia (NH3) and Carbon Dioxide (CO2) in order to yield urea. Potential research of urea synthesis under the magnetic induction zone at ambient room temperature and pressure has been introduced as one alternative method of bypass the use of ammonia process as an intermediate.
At current state, the design of microreactor for one step urea synthesis is not available. This study will address on focusing the effect of geometry angle on the mixing efficiency of the reactant gases through the Microchannel. In this proposal, the fluid flow and molecular motion on the gas mixing were demonstrated using Ansys-Fluent (CFD modeling) through trial and error method. By varying the geometry / angle of the Microchannel, different degree of mixing can be observed in order to determine the optimum location of the catalyst input based on three governing parameters ; Mixing efficiency , Pressure Drop and length of Microchannel. The fluid flow can be obtained by solving the Eulerian equation and molecular motion can be calculated using the discrete phase model. Outcome throughout this simulation project was to propose an optimum Microchannel geometry condition based on mixing quality and retention time of the gas reactant spend in the microreactor.