#### Energy Balance in Steady-State PFR: Screencasts

Introduction to setting up the general energy balance for a plug flow reactor (PFR).

We suggest you list the important points in this screencast as a way to increase retention.

Explains the terms in the energy balance for steady-state plug flow reactors.

We suggest you list the important points in this screencast as a way to increase retention.

##### Important Equations:

Energy balance for steady-state PFR-tubular reactor where A is reactant

$(\sum F_iC_{Pi})\frac{dT}{A_xdz} = \Delta H_Rr_A – \frac{4U}{D} (T-T_C)$

This can also be written in terms of cumulative volume instead of distance down the reactor

$(\sum F_iC_{Pi})\frac{dT}{dV} = \Delta H_Rr_A – \frac{4U}{D} (T-T_C)$

Initial conditions: at $$z = 0$$ (inlet to reactor), $$F_i = F_{i0}, T = T_0, C_i = C_{i0}$$

The corresponding mass balances to be solved simultaneously with the energy balance are :

$\frac{dF_i}{A_zdz} = r_i \hspace{1cm} or \hspace{1cm} \frac{dF_i}{dV} = r_i$

where $$F_i$$ = molar flow rate component of i
$$C_{Pi}$$ = molar heat capacity of component i
$$T$$ = temperature
$$A_x$$ = cross-sectional area of tubular reactor
$$z$$ = distance down reactor
$$V$$ = cumulative volume of reactor
$$\Delta H_R$$ = heat of reactor per mole of A reacting
$$U$$ = heat transfer coefficient
$$D$$ = reactor tube diameter
$$T_C$$ = temperature of coolant on outside of tube