Cryogenic Liquids
What are cryogenic liquids?
A cryogenic liquid is a liquefied gas with a boiling point temperature that is typically below [-150 oC]. Examples of gases that can exist as a cryogenic liquid include: Nitrogen, Oxygen, Argon, Helium, Neon, Krypton and Xenon. Liquid Carbon Dioxide is also referred to as a cryogenic liquid although it has a higher boiling point.
Buzwair Gases has the capability to produce high purity liquid and gaseous Nitrogen, Oxygen, Argon and Carbon Dioxide.
Production Process at Buzwair Gases
Cryogenic Liquid Nitrogen, Oxygen and Argon are produced from fractional distillation of air using air separation plants and techniques. These products are referred to as LIN, LOX and LAR respectively.
Liquid Carbon Dioxide (LCO2) is produced from a controlled combustion reaction between LPG and air using the most modern and state of the art technology, equipment and processes.
Air Separation for cryogenic liquid production
The raw material for cryogenic Nitrogen, Oxygen and Argon is air. The concentration of breathable air contains, by volume, approximately 78% Nitrogen, 20.9% Oxygen, 0.9% Argon, 0.03% Carbon Dioxide and the rest being moisture and rare gases. Air is withdrawn from the atmosphere through a dust filter by a multi-stage heavy duty air compressor unit. As air is compressed from stage to stage, the heat of compression is removed by heat exchangers using cooling water as the cooling medium.
The compressed air is further cooled using a refrigeration circuit to aid in removing moisture and carbon dioxide from the air. Moisture and carbon dioxide can cause blockages when the air is super-cooled as it will freeze and form dry-ice or ice blocks in the piping and distillation column. The air first pass through a moisture stripping unit that removes the bulk of moisture using metal-adsorption-desorption techniques before it passes through the Pre-Purification Unit (PPU) which removes the remaining moisture and carbon dioxide.
The compressed air that is chilled, moisture-free and carbon dioxide free, enters a super-heat exchanger which converts the air into cryogenic liquid air before it enters the distillation column. In the distillation column, the liquid air begins to separate into its individual components based on the thermodynamic properties of Nitrogen, Oxygen and Argon. The purity of the products leaving the distillation process is attained by continuous online analysis and reflux adjustments to ensure the highest purity is attained in the respective products. Liquid Oxygen (LOX) is directly obtained from the distillation column while high purity Liquid Nitrogen and Liquid Argon is obtained through additional purification, expansion and refrigeration of the respective gases leaving the column.
Due to the low boiling points of cryogenic liquids, the products are stored in vacuum insulated storage vessels.
Liquid Carbon Dioxide Production
Buzwair Gases produces high purity liquid Carbon Dioxide (LCO2) by a combustion reaction between LPG (Liquefied Petroleum Gas) and air in a reactor under controlled conditions. The initial product generated is referred to as flue gas and contains gaseous Carbon Dioxide (CO2) with other gas impurities which include Nitrogen, Oxygen, Argon and moisture. Through a series of purification processes involving the use of scrubber units, absorption towers and stripping columns, the final high purity gaseous CO2 is obtained. The CO2 gas is compressed and liquefied to obtain liquid Carbon Dioxide (LCO2). The final product is stored in special storage tanks with heavy-duty insulation to preserve the product and quality in its liquid phase.
Buzwair Gases can supply Liquid Nitrogen, Oxygen, Argon and Carbon Dioxide in the following packages to customers.
Product | Purity [%] |
|---|---|
| Liquid Nitrogen (LIN) | > 99.999 % |
| Liquid Oxygen (LOX) | > 99.98 % |
| Liquid Argon (LAR) | > 99.999 % |
| Liquid Carbon Dioxide (LCO2) | > 99.97 % |
Delivery options
| |