● Pressure drop in a pfr Determine X e for a PFR with no pressure drop, P = P 0. . Given that the system is gas phase and isothermal, determine the reactor volume when X = 0. ) affect the pressure drop and hence conversion. This reactor is created depending on mass balance as well as heat balance within a differential amount of fluid. Must use the differential form of the mole balance to separate variables: Rate Law. W is molecular weight of i. (for example) For liquids, v is constant so we can take it out of the differential. \begin{eqnarray} \frac{dX}{dW} &=& \frac{k'}{F_A0} \left ( \frac{1-X}{1 + \epsilon X} \right) y\\ \frac{dX}{dy} &=& -\frac{\alpha (1 + \epsilon X)}{2y} \end{eqnarray} In this session you will learn how to convert a first order catalytic reaction rate for use in the PFR. Pressure Drop & Rate Law Example: A plug flow reactor (PFR), also sometimes called a continuous tubular reactor (CTR) or piston flow reactor, is a model used to describe chemical reactions in continuous, flowing systems with a cylindrical geometry. Second order in A and irreversible: Stoichiometry. (The reverse reaction or equilibrium will be ignored in this tutorial. Diagram of a pipe showing pressure upstream and downstream. Instead of treact we have zreact! Flow is driven by the pressure drop across the pipe. 8 X e. If there is a pressure drop in a plug flow reactor, 1 there are two equations needed to determine the exit conversion: one for the conversion, and one from the pressure drop. The feed is stoichiometric in A and B. Determine X e for a PFR with no pressure drop, P = P 0. We need to know how to respond to "What if" questions, such as: "If we double the particle size, decrease the porosity by a factor of 3, and double the pipe size, what will happen to D P and X?" design equation for PFR. However, in gas phase rxns, conc’n is propotional to total pressure. ) Effects of Pressure Drop. Analyze the following second order gas phase reaction that occurs isothermally in a PBR: Mole Balance. Initial values: W=0, X=0, y=1 Final values: W=100 Combine with Polymath. A + 2B C is carried out in a packed bed reactor in which there is pressure drop. Isothermal, T In a plug flow reactor (PFR) there is no backflow or mixing, thus the flow of a fluid like a plug from the inlet side to outlet is shown in the below figure. 24 If δ≠0, polymath must be used to solve. Plot the conversion and pressure ratio y = P/P0 as a function of catalyst weight up to 100 kg. Figure 4. We want to learn how the various parameters (particle diameter, porosity, etc. In addition you will use the Ergun Equation to simulate the pressure drop within a PFR. In the absence of pressure drop or heat exchange, integral form of the design equation is used: = ⋅∫− X A A r dX V F 0 0 Pressure Drop in Reactors In liquid-phase rxns, the conc’n of reactants is not effected by the changes in pressure. mass flowrate ←const. 2. wkrvssxfdjcbcrltubuonlmirpbgcqcbnrzchmyylohfetufznx