Cryogenic air separation units for oxygen

The main components of atmospheric air are nitrogen (~78.08%) and oxygen (~20.95%).
In smaller amounts it contains noble gases (argon, neon, krypton, xenon), carbon dioxide, carbon monoxide (carbonous oxide), and other impurities.

Depending on its intended use, oxygen is supplied in the following types:

Technical oxygen – 99.5–99.7% O₂

Medical oxygen – 99.5% O₂

Process oxygen – 99.5–92% O₂ and lower.

The specifications for technical and medical oxygen are regulated by GOST 5583–78.

Oxygen produced by cryogenic oxygen plants is widely used in:

• A slightly more precise technical version would be:
• In foundry production to increase combustion temperature and improve product quality;
• In the chemical industry for the synthesis of sulfuric acid, ammonia, methanol and other substances;
• In non-ferrous metallurgy, to enrich the blast air in the smelting of copper, zinc, nickel, and other metals, which increases their yield;
• In medicine, rescue operations, the pulp and paper industry, and other sectors.

The main advantages of using cryogenic units:

• The ability to obtain high-purity oxygen with a minimal content of impurities in both liquid and gaseous form;
• Cost effectiveness for large production volumes;
• Long service life and high operational reliability.

Principle of operation

The technological process for producing high-purity oxygen is based on cryogenic rectification of air and is implemented using air separation units (ASUs). The process consists of several stages, during which the following operations are carried out:

• The air is compressed by compressor units to the required pressure;
• In the combined purification and drying unit, the air is cleaned of carbon dioxide, moisture, and undesirable hydrocarbons;
• The gas is liquefied, passes through a turboexpander and a system of heat exchangers, and is then fed into rectification columns to be separated into its main components and to extract rare elements: oxygen is withdrawn from the bottom of the column, argon from the middle, and nitrogen from the top.

The resulting gaseous oxygen is fed into gas holders and cylinders, and also supplied to the end user via a gas pipeline. Liquid oxygen is sent to tanks and containers for storage or transportation.

Structural features

• Use of alumina and zeolites as adsorbents in the air pre-purification unit (APPU) for efficient removal of moisture, carbon dioxide and hydrocarbons;

• Improved heat exchange efficiency and faster cooling and condensation processes due to the use of plate-fin heat exchangers made of aluminum alloys, which provide a high heat transfer coefficient and a compact design;

• Reduction of production costs through the combination of expansion in the turboexpander and compression in the compressor, which increases the energy efficiency of the unit;

• Efficient operation of the unit is ensured by the implementation of an automatic control and monitoring system, which includes sensors, programmable controllers, and signaling devices to protect against abnormal operating conditions.

The unit is adapted to the conditions and requirements of metallurgical plants: high equipment reliability, long operating campaign, a wide range of capacity control, and the ability to operate in areas with elevated air contamination.

The equipment complies with safety requirements for both the environment and operating personnel.

How and where to purchase an oxygen ASU

LLC RusGazKrio, the official dealer of Hangzhou Oxygen Plant Group, offers cryogenic equipment, including oxygen production plants, with subsequent installation and commissioning at the customer’s production site.
The unit capacity ranges from 10,000 to 120,000 Nm³/h, with oxygen purity from 99.5% to 99.9% vol.
At our production site in Krasnodar, an automated control system is developed in accordance with the customer’s technical specifications.

You can submit a request for a project calculation on our company’s website.
LLC RusGazKrio is a certified Siemens system integrator.
Our specialists design, manufacture, supply, deliver and commission air separation units (ASUs) in Moscow, as well as at industrial plants across Russia and CIS countries.
The equipment is adapted to the conditions of each specific production facility, with all required preliminary preparation carried out in advance.