Plug flow reactor pressure drop

PRESSURE DROP (AP) IN TUBULAR (PLUG FLOW) REACTORS... 

In our calculation we assume that the gas mixture approaches equilibrium under conditions where the pressure is constant. This situation corresponds, for instance, to a volume of gas moving through a plug flow reactor with a negligible pressure drop. (Note that if the ammonia synthesis were carried out in a closed system, the pressure would decrease with increasing conversion.)... 

Moreover, for negligible pressure drop through a plug flow reactor,... 

Plug flow reactors mostly operate at essentially constant pressure but sometimes pressure drop due to friction is appreciable. Thus problems P4.05.30 and P4.05.29 reveal a significant effect of friction on conversion and reactor size. For flow in pipelines, the pressure drop is given by... 

The use of monoliths as catalytic reactors focuses mainly on applications where low pressure drop is an important item. When compared to fixed beds, which seem a natural first choice for catalytic reactors, monoliths consist of straight channels in parallel with a rather small diameter, because of the requirement of a comparably large surface area. The resulting laminar flow, which is encountered under normal practical circumstances, does not show the kinetic energy losses that occur in fixed beds due to inertia forces at comparable fluid velocities. Despite the laminar flow, monolith reactors still may be approached as plug-flow reactors because of the considerable radial diffusion in the narrow channels [1]. 

The differences between the TBR and the MR originate from the differences in catalyst geometry, which affect catalyst load, internal and external mass transfer resistance, contact areas, as well as pressure drop. These effects have been analyzed by Edvinsson and Cybulski [ 14,26] via computer simulations based on relatively simple mathematical models of the MR and TBR. They considered catalytic consecutive hydrogenation reactions carried out in a plug-flow reactor with cocurrent downflow of both phases, operated isothermally in a pseudo-steady state all fluctuations were modeled by a corresponding time average ... 

Design and operation of gas-phase plug-flow reactors with multiple reactions where the pressure drop along the reactor is not negligible... 

Neglecting pressure drop, calculate the catalyst weight necessary to achieve 80 r conversion of ooctane in a CSTR and in a plug-flow reactor. If pressure drop is taken into account and the l-in. catalyst pellets are packed in ll-in. schedule SO pipes 35 ft lung, what catalyst weight is necessary to achieve SO "/ - conversion The void fraction is 40 and the density of the camlyst is 2.6 g/cm. ... 

The reaction, globally exothermic, takes place in an adiabatic Plug Flow Reactor at pressures of 25 to 35 bars and temperatures between 620 and 720 °C. Large excess of hydrogen, typically 5 1 molar ratio, prevents the formation of coke. The reaction conversion is typically 60-80%, because at higher value the selectivity drops rapidly. 

Plug flow reactors are applied mainly for gas-phase reactions. Heat transfer coefficient inside the reactor tube usually controls the overall heat transfer. High turbulent flow regime is recommended. However, the fluid velocity is constrained by the allowable pressure drop, by the feasible reactor length, catalyst attrition, etc. Figure 8.20... 

From experiments in a constant volume batch reactor at 791K, it is known that the time required for a 50% increase in total pressure is 197 s. The initial pressure is 1 bar. The reaction is known to be second-order in acetaldehyde. Determine the volume of a plug flow reactor necessary to achieve 80% conversion of 120 L/min of pure acetaldehyde gas. The feed pressure is 1 atm. The reaction is essentially irreversible. The pressure drop along the length of the reactor is negligible. 

Delsman et al. [9] proposed a method to predict the influence of flow maldistribution and manufacturing tolerances on the performance of a microreactor with a large number of parallel channels. In this method, a variable reactor parameter (e.g., diameter) is considered as a random parameter with a mean value and a standard deviation, and the microreactor is considered as a plug-flow reactor. Then, a number of relationships between the variable parameter and efficiency as compared to the ideal case are presented. The pressure drop as a function of the mean channel diameter is given by Equation 9.5 ... 

In chemical reactors, only pressure drop and friction forces have to be considered in most cases. A number of specific pressure drop equations are discussed in the chapters on tubular plug flow reactors and on fixed bed catalytic reactors. 

The selective oxidation of CO in the presence of H2 is being carried out in a catalytic, ideal plug-flow reactor at atmospheric pressure and 100 °C. Although the reactions are exothermic, we will assume that the reactor is isothermal in order to develop a preliminary understanding of reaction behavior. We also will neglect pressure drop, assume that transport effects are negligible, and assume that the ideal gas laws are valid. 

Riser (More than one can be present) Convert feed to product species using 21-lump kinetics Modified plug-flow reactor (PFR) Allows any angle of inclination Pressure drop is a combination of pressure drop due to solid and vapor phases... 

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