Evaluation tubular reactor design

Barnes CM. Evaluation of tubular reactor designs for supercritical water oxidation of U.S. Department of Energy mixed waste. INEL-94/0223, Lockheed Idaho Technologies Co., Idaho Falls, ID, 1994. 

C. M. Barnes, Evaluation of Tubular Reactor Designs for Supercritical Water Oxidation of U.S. Department of Energy Mixed Waste, Idaho National Engineering Laboratory Report INEL-94/0223, December, 1994. 

The design equations for ideal tubular-flow reactors involve no new concepts but simply substitute a rate of reaction for a heat-transfer rate or mass-transfer-rate function. The increased complexity of reactor design in comparison with the design of equipment for the purely physical processes lies in the difficulty in evaluating the rate of reaction. This rate is dependent on more, and less clearly defined, variables than a heat- or mass-transfer coefficient. Accordingly, it has been more difficult to develop correlations of experimental rates, as well as theoretical means of predicting them. 

Evaluate the results obtained in problems 8 and 14, Chapter 4, in terms of the criterion developed by Meats for freedom from axial dispersion effects in tubular reactors [D.E. Meats, Ind. Eng. Chem. Proc. Design Devel., 10, 541 (1971)]. 

Notice that the molar density of key-limiting reactant A on the external surface of the catalytic pellet is always used as the characteristic quantity to make the molar density of component i dimensionless in all the component mass balances. This chapter focuses on explicit numerical calculations for the effective diffusion coefficient of species i within the internal pores of a catalytic pellet. This information is required before one can evaluate the intrapellet Damkohler number and calculate a numerical value for the effectiveness factor. Hence, 50, effective is called the effective intrapellet diffusion coefficient for species i. When 50, effective appears in the denominator of Ajj, the dimensionless scaling factor is called the intrapellet Damkohler number for species i in reaction j. When the reactor design focuses on the entire packed catalytic tubular reactor in Chapter 22, it will be necessary to calcnlate interpellet axial dispersion coefficients and interpellet Damkohler nnmbers. When there is only one chemical reaction that is characterized by nth-order irreversible kinetics and subscript j is not required, the rate constant in the nnmerator of equation (21-2) is written as instead of kj, which signifies that k has nnits of (volume/mole)"" per time for pseudo-volumetric kinetics. Recall from equation (19-6) on page 493 that second-order kinetic rate constants for a volnmetric rate law based on molar densities in the gas phase adjacent to the internal catalytic surface can be written as... 

Comparison of Eqs. (4-2) and (4-5) shows that the form of the design equations for ideal batch and tubular-flow reactors are identical if the realtime variable in the batch reactor is considered as the residence time in the flow case. The important point is that the integral c/C/r is the same in both reactors. If this integral is evaluated for a given rate equation for an ideal batch reactor, the result is applicable for an ideal tubular-flow reactor this... 

Evaluate the ITM Syngas/ITM H2 processes using PDU data Conduct long-term stability tests of tubular membranes and seals at high pressure Demonstrate performance of pilot-scale membrane modules in PDU Complete membrane module design and select catalysts for the SEP Commission the ceramic Production Development Facility and fabricate SEP membranes Design and fabricate the SEP reactor... 

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