Plug flow reactor variable density

ILLUSTRATION 8.4 DETERMINATION OF REQUIRED PLUG FLOW REACTOR VOLUME UNDER ISOTHERMAL OPERATING CONDITIONS—VARIABLE DENSITY CASE... 

Equations (13-16a) are of the same form as the equations for homogeneous plug-flow reactors [Eq. (4-5)] they are the constant-density version because the system is isothermal, and because for gaseous reactions no allowance has been made for a change in number of moles. Equation (12-2) is the analog of Eq. (3-13) for heterogeneous reactions and is applicable for variable-density conditions. The application of these equations to reactor design is the same as discussed, for example, in Example 4-6. 

Note that Eqs. 10.2.b-l, 7, and 10 do not explicitly contain the residence time, just as was the case for the continuity equations for the plug flow reactor in Chapter 9. They could be reformulated (e.g., see Levenspid [3]) but, again as in Chapter 9, there is no advantage, and it is simpler to just use the directly manipulated variables Fao, y> and Cao It is only in constant density systems that the residence time, V/F, directly appears, as is illustrated by Eq. 10.2b-4. 

ILLUSTRATION 8.4 Determination of Plug Flow Reactor Volume Required for Isothermal Operating Conditions Variable Density Case... 

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