CO2 Liquefaction Plant

Pakarab Fertilizers Ltd. Multan

Scope

Introduction What is liquefaction? Design Basis Process Flow Diagram Major Equipments Refrigeration System Applications of CO2

Introduction

The CO2 Recovery Plant is designed for the recovery of impure, low pressure CO2 gas from the ammonia plant by-product gas and produce purified, high pressure liquid CO2.

Capacity 8MT/h. Liquid CO2 Temperature= -20 C

Pressure = 21 bar

What is Liquefaction?

The liquefaction of gases is a complicated process that uses various compressions and expansions to achieve high pressures and very low temperatures Liquids.

The process of refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure, also below the critical pressure.

Design Basis

Component Feed Gas Product Liquid

CO2 78.92% 99.94 %

H2O 18.74 % 0

CO 0.004063 % 0.000204 %

N2 0.879 % 0.012 %

Ar 0.15 % 0.046415 %

H2 1.3 % 0

Acetaldehyde 0.004 % 0

Methanol 0.0055 % 0

Benzene 0.000001 % 0

Major Equipments

Screw Compressors Knock Out Drums Coolers Condenser Evaporative Condenser Dryer Scrubber Stripper

Screw Compressor

The single screw oil lubricated compressor is a rotary, positive displacement compressor which incorporates a main screw and two gaterotors.

Range 100psig-350psig Easy capacity control Less moving parts Less maintenance cost

CO2 Gas Scrubbing

Removes water soluble impurities Counter Current Flow of Gas Water Level Control Flow control of raw water

Knock Out Drums

Removes moisture Deflective Plate Demister pad Auto drain system

Coolers and Condenser

Flooded type heat exchangers Level control of refrigerant Refrigerant Pressure Control

CO2 Gas Dryer

Deodourizer

Desiccant

Activated Carbon

Selexsorb CD

Molecular Sieve

FeaturesAMLOC Probe

Dew Point Analyzer

Stripping System

Stripping of impure liquid CO2 is carried out by counter current flowing pure CO2 vapors from reboiler

CO2 gas venting from top is recondensed by reflux condenser

Refrigeration System

This system includes Two Screw Compressors Evaporative Condenser Receiver Throttling in let valves Evaporators (Exchangers)

PT Diagram of Ammonia

Ammonia Evaporative Condenser

Major Parts Cooling Coils Drift Eliminator Air Inlet Louvers Induced Draft Fan Distribution Nozzles

Applications of CO2

Beverages Dry Ice Food preservation Urea Manufacturing Fire Extinguishing

Pakistan Market

85%

5% 5% 5%

Beverages Food Preservation Dry Ice Others

Thank You