Cryogenic Air Separation Plants

Red Mountain Energy offers a wide model range of cryogenic air separation plants (ASPs).

The cryogenic cycle for the separa¬tion of air is energy efficient and also allows different modes to operate within one unit. All our ASPs can be adapted to the custom¬er's requirements.

Advantages of cryogenic ASPs:

• High purity products
• Simultaneous production of several products
• Gas and/or liquid products
• Less power consumed
• Reliability and long service life

Types of cryogenic air separation units (ASUs)

Cryogenic cycles

ASUs are built to accommodate efficient cryogenic cycles: the low-pressure turbo-expander cycle, a cycle with two pressures and a cycle with an independent circulation loop. In addition, ASUs use the method of re-compression in which the turboexpander compresses process streams.

Air drying and purification

The plant contains an adsorption type module for air dehydration and purification. Each adsorber is filled with two adsorbent layers: active alumina oxide and zeolite (molecular sieve). The regeneration of the adsorbent is performed by waste gas, at a temperature of up to 180 degrees C.

High operating reliability and purified air quality are due to:

• Replacement of self-acting non-return valves, which cannot be controlled by the power-actuated valves with the remote positioning control
• Use of efficient adsorbents and continuous treatment quality control
• Gas analyzer to monitor the purity of air at the outlet of adsorbers
• Heater backup system (operating + standby)
• Ability to install a steam heater to reduce power consumption as an alternative to the electric heater

Dry insulation

The cold box is insulated thermally by filling the void space of the pressure-tight casing with perlite. To improve the quality and reli¬ability of insulation, "dry insulation" is used which keeps a permanent positive pressure of dry nitrogen inside the insulation space, and so prevents any penetration into the ASU of moisture from the atmosphere.

This method guarantees the cold box a long service life and avoids corrosion inside the cold box and possible mechanical damage due to ice accumulation.

"Dry insulation" does not suffer the destructive effects of moisture and retains its properties throughout its entire lifetime. High quality insulation means minimum heat leaks which, in turn, leads to a reduction of power consumption.

Finding the right materials

Inside the cold box (eg. columns, heat ex¬changers, pipelines) we use only aluminium alloys. This eliminates problems which arise when more than one material is used. Carbon steel is used to fabricate equipment and pip¬ing in "warm" systems.

Control system

Air separation plants are equipped with a control system based on Programmable Logic Controllers (PLC) which collect and process information, and generate and release control signals.

Operators can follow all stages of the air separation process on screen. This high level of automation is efficient and cost effective.

Benefits of the control system

• High level of automation, with automatic stop/start and remote control
• Maximum efficiency of process technology
• Analysis of process technology with parameters back-up

Our air separation plants are based on the latest innovative technology, use energy efficient processes and can operate in different modes.