Cryogenic Liquid Plant

Cryogenic Liquid	Manufacturing process	Benefits
Equipment Required	Buyers Guide

Cryogenic liquid plants are gas plants producing liquid oxygen or liquid nitrogen in the cryogenic process. Cryogenic process is one of the most popular technique used in many large scale gas plants for producing purified oxygen or purified nitrogen. The output of liquid oxygen produced from the plant can be stored in a liquid oxygen tank. Liquid nitrogen is produced as a by product simultaneously upto 99.999% purity. The cryogenic plants are extremely versatile, safe and easy to operate and all the possible product variants that are produced can be taken as either 100% liquid oxygen out put or 50% liquid oxygen output directly into cylinders or 50% liquid nitrogen and 50% liquid oxygen.

What is Cryogenic Liquid?
A refrigerated, severely cold (-60ºC to -270ºC) and pressurized liquid gas. Under different conditions of temperature and pressure, different cryogens become liquids. All cryogenic liquids have two features in common:

• They are very very cold.
• Small amounts of liquid can grow into very large volumes of gas.

Types of Cryogenic Liquid

• Liquid nitrogen
• Liquid oxygen
• Liquid argon
• Liquid helium

Manufacturing Process of Cryogenic Liquid in Cryogenic Plants.
Air is sucked by a multi stage air compressor and air passes through the following process.

• Compression of air: This is accomplished by multistage highly efficient air compressor.
  
  
• Purification of air: Purification of air is dome by an important component of the gas plant known as process skid.
  
  
• Cooling & liquification of air: A highly efficient expansion engine and a refrigeration unit (for 100% liquid output) are used for cooling and liquification.
  
  
• Air separation (rectification): Air separation is done in an air separation unit consisting of upper & lower column and special exchangers. The separation air is done by the cryogenic process and the final output whether a liquid oxygen or liquid nitrogen or both goes to the storage tank.

Benefits of Cryogenic Liquid Plants
Besides producing pure liquid oxygen and nitrogen, cryogenic liquid plants are used directly in other processes:

• Hydrogen recovery
• Hydrogen purification
• Liquid petroleum gas (LPG) recovery from refinery off gas
• Ethane and ethylene recovery
• Purification of carbon monoxide
• Nitrogen purification of ammonia syngas
• Natural gas processing for recovering NGL and helium

Equipment required in Cryogenic Liquid Plants

• Suction filter
• Air compressor
• Process skid
  • After cooler with tank
  • Nitrogen cooler with tank
  • Moisture separator
  • Chilling unit
  • Oil absorber
  • Molecular sieve battery
  • Defrost heater
  • Gas/Air/water line as per standard layout on skid
  • Water pump
  • Inlet & outlet water lines
• Expansion engine
• Air separation unit
• Liquid oxygen pump
• Cooling tower
• Water softener

Buyer's Guide: Technical specifications

• Capacity (Product Options):
  • Oxygen liquid 100%, Nitrogen gas
  • Oxygen liquid 50%, Oxygen gas 50%, Nitrogen gas
  • Oxygen gas at 50%, Nitrogen liquid 50%, Nitrogen gas
• Purity : Oxygen, nitrogen (optional upto 99.999%)
• Power connected
• Power consumed (abt.): 50% gas 50% liquid, 100% liquid
• Power supply
• Air capacity
• Starting pressure
• Working pressure (abt): 50% gas 50% liquid, 100% liquid
• Starting time (after defrost)
• Starting time (after tripping)
• Areas required
• Assembly height
• Weight (about)
• Air separation column