Plug Flow Reactor Design

1.1.7Plug flow Reactor design

In a plug flow reactor the composition of the fluid varies from point to point along a flow path; consequently, the material balance for a reaction component must be made for a differential element of volume dV. Thus for a reactant A the mass balance becomes; Input = output +disappearance by reaction + accumulation Where accumulation is zero thus, the equation becomes; Input = output + disappearance by reaction Calculation of reactor volume is by the following equation,

 Notation V FAO XA τ CAO A(subscript) rA

Volume of reactor Feed flow rate ( kgmolh -1) Fractional conversion of DIPB Space time (kg h kgmol -1 ) Initial concentration of DIPB DIPB

Rate of disappear disappearance ance of species species A(DIPB) A(DIPB) (kgmol kgcat-1hr -1) 

Transalkylation reactor design data

Table 1.2

Initial DIPB concentration C DIPBO

Kgmolm-3

Initial DIPB flow rate F DIPBO Specified DIPB conversion X DIPB Catalyst Voidage fraction ε A

(From mass balance) 0.95 0.5

To determine the volume of reactor the following steps were followed; 1. Weight Weight of cataly catalyst(equ st(equation ation adapted adapted from Kondamudi,upa Kondamudi,upayadhula yadhula)) (1.1)

(1.2)

Evaluating the integral of the above equation using simpson’s rule;

(1.3)

Wcat= kg 2. Volume of catalyst (1.4)

(1.5) m3

V=

3. Volume of reactor required (1.6)

4. Actual volume of reactor, a 10% allowance for the heads

Vact = 5. Diameter of reactor, as a rule of thumb the diameter to length ratio is 5(L/D=5) Since

D=m

6. Length of reactor  L=5D L=

m

Reactor design specifications Catalyst weight Reactor volume

kg m-3

Reactor inside diameter Reactor length

m m