Chapter 7, Problem 7.57P

(A)

Interpretation Introduction

Interpretation:

The labeled flow diagram should be drawn.

Concept Introduction:

Hydrocarbon gas enters at 500 o C and it is combined with light oil at 25 o C.

The combined stream leaves at 200 o C

Hydrocarbon gas Temperature, T₁=500 ^oC

Light oil Temperature, T₂ = 25 ^oC

Exit Combined stream Temperature, T₃= 200 ^oC

(B)

Interpretation Introduction

Interpretation:

D/F ratio should be determined.

Concept Introduction:

The general energy balance of the mixing process is given as below for an adiabatic vessel: -

  $F.C_{pgas}.(T_3-T_1)+D.\left[\Delta H^{lv}+C_{Poil}.(T_3-T_2)\right]=0$

Where,

C_Pgas = Molar heat capacity of hydrocarbon gas=150 J/(mol.K)

C_Poil = Molar heat capacity of light oil = 200 J/(mol.K)

R = Universal Gas Constant

T₁ =Inlet temperature of Hydrocarbon gas = 500^oC

T₂ =Inlet temperature of Light oil = 25^oC

T₃ =Inlet temperature of Mixed stream = 200^oC

  $\Delta H$ lv = Change in Enthalpy = 35000 J/mol at 25 ^oC

F = Molar feed rate of hydrogen gas

D = Molar feed rate of light oil

(c)

Interpretation Introduction

Interpretation:

To explain the advantage of using a liquid rather than cooler gas

Concept Introduction:

Quenching is defines as rapid cooling of a substance using a medium such as oil in this case.