PTT 255 REACTION ENGINEERING CONVERSION REACTOR SIZING PART

PTT 255 REACTION ENGINEERING CONVERSION & REACTOR SIZING PART 1 - (CONVERSION) 1 Dr Noor Hasyierah Mohd Salleh Department of Chemical Engineering Technology

OUTLINE Conversion Batch Reactor Design Equation Flow Reactors Design Equations CSTR PFR PBR 2

CONVERSION A-->B, Xmax, irr = 1 A⇌ B, Xmax, rev = Xe 3

CONVERSION 4

BATCH REACTOR DESIGN EQUATION Moles of A reacted · [Moles of A reacted/consumed] = [Moles of A fed] Moles of A reacted Moles of A fed · [Moles of A reacted/consumed] = [NA 0] [X] Moles of A that have Moles of A initially Moles of A in been consumed by fed to reactor at time t chemical reaction t = 0 [NA ] [NA 0 ] NA N A 0 [NA 0 X] (1 X)

BATCH REACTOR DESIGN EQUATION Moles of A reacted NA NA 0 X [1] Differentiating wrt time; [2] Recall mole balance for batch reactor (Chapter 1); Rearranging and substituting into ; [2] [Design Equation in terms of conversion]

BATCH REACTOR DESIGN EQUATION Design Equation (in terms of conversion, X ): [3] What is the time required to achieve a specific conversion? Integrating [3] with limits (t=0, X=0; t=t, X=X )

BATCH REACTOR DESIGN EQUATION For constant-volume batch reactor; V=V 0 [ Design eq. from Chapter 1] [Rearranging] [Re-write in terms of concentration] 8

FLOW REACTORS DESIGN EQUATION Moles of A reacted · Moles of A reacted/consumed = Moles of A fed time Moles of A reacted Moles of A fed · = [FA 0] [X] Molar flow rate at which A leaves the system Molar rate at which A is fed to the system [FA ] [FA 0 ] FA F A 0 Molar rate at which A is consumed within the system [FA 0 X] (1 X)

FLOW REACTORS DESIGN EQUATION FA FA 0 X Concentration Partial Pressure Ideal gas law

FLOW REACTOR : CSTR Recall Design Equation for CSTR (Chapter 1); [1] Substituting into [1] F F F X A Rearranging; A 0 11

FLOW REACTOR : PFR Recall Mole Balance for PFR (Chapter 1); [1] We know that [2] FA FA 0 X Differentiating [2] wrt X [3] Substituting [3] into [1] [4] 12

REACTOR FLOW : PFR [4] Integrating [4] with limit V=0 when X=0; 13

FLOW REACTOR : PBR Design equation for PBR; Similar to that of PFR except these terms: Catalyst weight ; V W -r. A -r’A 14

SUMMARY OF DESIGN EQUATION Reactor Differential Form Batch CSTR Algebraic Form Integral Form - - PFR PBR

CONTINUE TO PART 2… 16