Packed Bed Reactor Report

i- Abstract Packed Bed Reactor is used for exothermic reaction of H2S over a catalyst base with SO2to produceSulfur and water. The reaction is called Claus Reactor. The Chemical and Mechanical Design of PBR have been done with calculations of kinetic rates, reaction rate, weight of catalyst, reactor length, pressure drop, pipe thickness.

The Reaction is

2H_2 S + SO_2 ↔ 3/8 S_2 + 2H_2 O

Table of Contents

Title Page No.

Abstract..................................................................................................................................i

1.0 Introduction.....................................................................................................................1

2.0 Process Description..........................................................................................................2

It is known that H_2 S causes health hazards such as, eyes, skin, and respiratory system irritation. According to the air pollution regulations on sulfur compounds, the removal of hydrogen sulfide is environmentally beneficial as it is a source of producing several dangerous chemical compounds such as, SO_2, H_2 SO_3 and H_2 SO_4. Sulfur is one of simplest and most important product produced worldwide and use in the production of Sulfuric Acid, Fertilizer, Pesticides, Sulfur-Extended Asphalt. Sulfur is produced by Claus exothermic of H_2 S with SO_2using alumina based catalysts at 433K and 1.5 bar. The Composition is 0.0772%molH_2 S, 0.0386%mol SO_2, 0.2581%mol H_2 O, and 0.6261%mol N_2. The Claus Reaction

2H_2 S + SO_2 ↔3/8 S_2 + 2H_2 O Kinetic Equation and reaction rate and Activation Energy of the reaction is taken from the reference (1). r=k_1 (T) P_H2S P_SO2^0.25-k_2 (T) P_H2O In the above equation if we put P_i=C_i RT then we have: r=k_1 (T) (RT)^1.25 C_H2S C_SO2^0.25-k_2 (T)(RT) C_H2O k_1 and k_2 are defined as bellow:

k_1=K_10

Figure (3): Graph results from poly math. Pressure Drop Calculation: Use Ergun Equation: dy/dW= (-α)/2y.(F_T/F_To ).(T/T_o ) = (-α(1+εX))/2y.(T/T_o )

Let,

Pressure = P= kpa

Φ= Void fraction= porosity= 0.445 g_c=1 (kg.m)/(s.N)

D_p=Diameterofparticleinbed(m)=0.0047 m viscosity of mixture of gas in Catalyst bed is calculated by Champman-Enskog theory: µ=(-10.035+0.25191T-0.00037932T^2 )x3.6x〖10〗^(-4)=0.033 kg/(m.s) superficial velocity=u=volumitric flow rate/Ac=v_0/A_c =(0.34/14.20)/(π/4 (1.95)^2 )=0.023/2.99=0.0076 m/hr gas density with assumption of ideal gas= ρ_o=PM/RT=(1.5)(34.08)/(0.008314)(433) =14.20 kg/m^3

Volumetric flow rate=v=v_o (1+εX)(T/T_o )=0.023 (1-0.70)(438/433)=0.0069 m^3/s gas density=ρ=ρ_o (v/v_o )=14.20(0.023/0.0069)=47.3 kg/m^3 superficial mass velocity=G=(ρ.v)/A_c =(47.3)(0.0069)/2.99=0.11 kg/(m^2.s) β_o= -(G/(ρ.g_c.D_o ))((1-Φ)/Φ^3 )((150(1-Φ)μ/D_0 )+1.75G) β_o=(0.11/(14.20)(0.0047) )((1-0.445)/〖0.445〗^3 )(((150)(1-0.445)(0.033)/0.0047)+(1.75)(0.11))=6068.8 N/m^3 a= (2β_o)/(A_c ρ_c D_p (1-Φ) P_0 )=(2)(6068.8)/(0.023)(1900)(0.0047)(1-0.445)(150) =885.32 〖kg〗^(-1) dy/dW=(-.67(1-0.7))/2y (438/433) dy/dW=134.3/y dy=0.10/y(234.95)

∫▒ydy=0.57

y^2/2=0.57