Presented By: Muddassar Sultan

Catacarb Section

National University of Sciences & Technology

Catacarb Section It consists of following main equipments:

• High Temperature Shift Converter

• Low Temperature Shift Converter

• Desuperheater

• Absorber

• Stripper

• Rich Solution Flasher Drum

• Knock Out Drums

Following main operations are carried out:

• Conversion of CO to CO2.

• Removal of CO2 from Synthesis Gas.

High Temperature Shift Converter

• Reaction:

CO + H2O(s) H2 + CO2

• Conditions: o Inlet Temperature: 675oF - 700oF

o Outlet Temperature: 750oF

o Catalyst: Iron

o Pressure Drop: 5psi

• Composition:

Composition Inlet % Outlet %

H2 56.25 60.25

CO 12.38 2.18

CO2 7.96 16.24

Heat Exchangers

103-C

104-C

1112-C

BFW (Tube Side)

Methanator Feed (Shell Side)

BFW (Tube Side)

Bypass From HTS

To LTS

Low Temperature Shift Converter

• Reaction:

CO + H2O(s) H2 + CO2 (Continued)

• Conditions: o Inlet Temperature: 410 F

o Outlet Temperature: 435 F

o Catalyst: Copper

o Pressure Drop: 5psi

• Composition:

Composition Inlet % Outlet %

H2 60.25 61.2

CO 2.18 0.21

CO2 16.24 17.5

Operating Parameters

• Temperature in HTS should not exceed 950oF:

– Catalyst Inactive

– Vessel Damage

• Catalyst deformation is detected via pressure

drop

104-D

HTS

103-C

104-C

1112-C 108-D LTS

700o F

760o F

630o F

530o F

400o F

TRCE Control Valve

HTA

HCV

PB

From Reformer

To Desuperheater

Process Flow Diagram

PDIa-17

Desuperheater LTS effluent at 440oF is quenched to 350oF using process condensate

Desuperheater

1105 CA & CB

102-F

Raw Gas Separator vessel

To Absorber 440oF

350oF

260oF

Rich Solution

Lean Solution

Syn Gas CO2 free

Raw Syn Gas

101-E

Absorber:

HLA

LLA

LICe

•Low Temperature & High pressure

•Polypropylene Flexi rings & Stainless Steel rings packing

•Catacarb Solution is used to absorb CO2:

K2CO3 + CO2 +H2O 2KHCO3

•Other components of Catacarb solution are:

- K2CO3 (35%)

- Glycol (Defoamer)

- Corrosion inhibitor

- Diethanol Amine & Tertiary Ethanol Amine

(enhance absorption capacity)

Semi-Lean

AR

Lean Solution 16% CO2 Semi Lean 35%CO2

Rich Solution 75%CO2

1105C

A&B 1111C

Stripper: Rich Solution

Lean Solution

Semi-Lean

•High temperature & Low Pressure

•Polypropylene Flexi rings & Stainless Steel rings packing

•CO2 is stripped off the rich solution:

2KHCO3 K2CO3 + CO2 +H2O

•Three Exchangers are provided at the bottom to provide heat

•Air injection to regenerate reduced V2O5

•Glycol addition for avoiding foaming

CO2 to

Urea

LLA

HLA

LRe

Rich

Solution

Flasher

1103-E

Absorber Stripper

Gases

107-JT

PDIe HPDA

Rich Solution

Semi Lean Solution

Knock Out Drum Working

CO2 Recovery

• CO2 may be recovered by the flue gases out of the primary

reformer……..?

• CH4 + O2 CO + CO2 + H20

• Main Constituents of flue gases:

– SO2

– NO2

– CO

– CO2

Thank You For Your Attention…..!

Questions.…?