Results

You will see how temperature develops in radial and axial direction from t = 0 s to t = 400 s as the feed enters the reactor. The exothermic reaction will begin as the preheating precedes and temperature rises in the reactor. It takes about 35 seconds until the feed is heated to the reaction temperature, 303 K. Because of the laminar flow, the molecules near the reactor wall will spend longer time in the reactor than the ones at the center and the conversion of A and B will therefore be higher close to the reactor wall. Since more of A and B reacts near the wall the temperature will be higher there. However, the cooling effect lowers the temperature at the wall and the highest temperature can be seen a short distance from the wall. This of course affects the conversion of A and B. The average temperature of the product flow after 400 s is 325 K. To see how the temperature varies with time during startup of the reactor, click on the link below reactor (don't be confused by the slightly offset r-axis scale in the video).

 

Temperature profile animation

 

You will see how concentration develops in radial and axial direction from t = 0 s to t = 400 s as the feed enters the reactor. As the reactants enter the reactor containing only solvent, the frontline of the flow gets diluted by the solvent, which lowers the reaction rate a bit. After about 80 s the feed is warm enough and the reaction starts. Due to the laminar flow, more A and B will react close to the wall than at the center because the reactants are in the reactor for a longer time near the wall. Even though the temperature is less at the wall than a short distance from the wall, the concentration of A will not decrease because of the larger space time. Once the reactor reaches steady state at about 400 s the average concentration in the product stream is 175 mol/ m³. To see how the concentration of species A varies with time during startup of the reactor, click on the link below reactor (don't be confused by the slightly offset r-axis scale in the video).

 

Concentration profile animation