Chemical Plant Air Separation Unit

Core Technology

Strong corrosion-resistant design: Core components are constructed of 316L stainless steel, and valves feature Hastelloy alloy valve cores . The external fluorocarbon coating provides 1,000+ hours of salt spray resistance, flanges feature double-pass PTFE seals, and the electrical control cabinet is IP54-rated for use in harsh chemical environments.

Dual pretreatment ensures power supply: The system includes dual molecular sieve adsorption towers and filters, enabling online switching and regeneration without downtime. Core equipment retains a 10%-15% load margin to accommodate peak gas demand fluctuations.

Intelligent temperature control ensures stable operation: The system is equipped with a chemical-grade DCS system, which monitors over 200 parameters in real time and automatically generates alarms and shutdowns in the event of an abnormality. The mean time between failures (MTBF) is ≥10,000 hours, 25% higher than general-purpose equipment.

 

Scenario-based customized solutions: Coal chemical industry provides an "oxygen + nitrogen dual-product system" (oxygen ≥ 99.6%); petrochemical industry provides a "low-energy nitrogen system"; fine chemical industry provides an "argon + removal module".

 

Comparison Table of Three Main Air Separation Unit (ASU) Technologies for Chemical Plants:
 

Technology Type	Core Principle	Key Advantages	Limitations	Typical Chemical Industry Applications
Cryogenic Distillation	Utilizes the boiling point differences of air components to achieve separation in low-temperature columns through the process of "compression → pre-cooling → purification → deep cooling → distillation".	Large output , high purity (O₂/N₂ ≥ 99.999%), stable operation.	High investment cost, long start-stop time , high energy consumption.	Large-scale coal chemical industry , petrochemical industry.
Pressure Swing Adsorption (PSA)	Adsorbents (e.g., molecular sieves) selectively adsorb O₂/N₂ under different pressures; separation is achieved through cyclic "pressurized adsorption → depressurized desorption" to remove impurities or target components (e.g., N₂).	Low investment cost, fast start-stop (tens of minutes to several hours), flexible operation (adapts to fluctuating load).	Limited output (single unit ≤ 10,000 Nm³/h), moderate purity (O₂: 90%-95%), regular adsorbent replacement (3-5 years).	Inert protection for small-to-medium chemical reactors, auxiliary combustion for small incinerators, temporary gas supply during maintenance.
Membrane Separation	Relies on the difference in permeation rates of O₂ and N₂ through polymer membranes to achieve separation driven by the pressure difference across the membrane.	Compact size , simple maintenance (no moving parts), extremely fast start-stop .	Low purity (O₂ ≤ 40%, N₂ ≤ 99.5%), high energy consumption, small output (single unit ≤ 1,000 Nm³/h).	Micro-positive pressure protection for chemical storage tanks, low-concentration O₂ supply for small laboratories.

 

The performance and safety of chemical ASUs are controlled through strict technical indicators and standards. Core indicators include:
 

Core Performance Indicators
Product Purity: O₂ purity (volume fraction) ≥ 99.6% (GB/T 3863), N₂ purity ≥ 99.999% (GB/T 8979), Ar purity ≥ 99.999% (GB/T 10624);
Specific Energy Consumption: The "oxygen consumption"of a deep-freeze ASU is typically 0.45-0.6 kWh/Nm³ , a core indicator for measuring equipment energy efficiency;
Load Adjustment Range: Chemical ASUs must have flexible load adjustment capabilities, typically operating stably within a range of 60%-110% of the design load;
Reliability: Annual operating time ≥ 8,000 hours (chemical plants typically operate continuously, and ASUs are typically operated continuously). A failure could shut down the entire chemical plant, resulting in significant losses.
 

Core Safety Standards

Domestic: "Air Separation Equipment Using Deep Freezing Methods" , "Safety Technical Specification for Oxygen and Related Gases";

International: Compressed Gas Association (CGA) standards in the United States and EN standards in the European Union.

1. Which air separation unit is suitable for a chemical plant? How should I choose based on production needs?
Prioritize cryogenic distillation and PSA/VPSA types. For coal chemical and petrochemical applications, choose cryogenic types (supporting 70%-105% variable load). For fine chemicals with low purity requirements, PSA/VPSA are more economical.
 

2. What core performance characteristics should I consider when purchasing to ensure suitability for the harsh environment of a chemical plant?

Four key points: ① Corrosion resistance (316L stainless steel and Hastelloy alloy components, fluorocarbon coating with salt spray resistance ≥ 1000 hours); ② Continuous operation capability (online regeneration of the dual molecular sieve column without downtime, with a 10%-15% load margin for the compressor); ③ Safety and stability (DCS monitoring of 200+ parameters, automatic alarms for abnormalities, and MTBF ≥ 10,000 hours); ④ Energy consumption (oxygen consumption ≤ 0.55 kW·h/m³ for medium-sized cryogenic units).
 

3. Can the supplier customize for specific chemical applications? What information do I need to provide?
Customizable options include the coal chemical industry's "oxygen + nitrogen dual-product system" (oxygen ≥ 99.6%), the petrochemical industry's "low-energy nitrogen system," and the fine chemical industry's "argon + removal module" (argon ≥ 99.9999%). Required information includes: gas type/purity/hourly output, site environment, load fluctuation range, and special requirements .
 

4. What after-sales and warranty services should I confirm to mitigate operational risks?
① Qualifications (ISO 9001/14001 certification, third-party testing of core components); ② Warranty (1-2 years for the entire system, with extended warranties available for core components such as compressors); ③ Service (24-hour technical support, on-site installation training, and a nearby spare parts warehouse); ④ Performance commitment (a contract guaranteeing purity/output/energy consumption, with compensation for non-compliance).
 

5. For large-scale chemical projects, should I choose modularization (integrated cold box) or on-site assembly?
Modularization is more cost-effective: ① Installation costs are reduced by 30%-50% (factory pre-assembly, reducing on-site workload); ② Quality is more stable (assembly in a controlled environment, reducing welding deviations); ③ Commissioning is faster (startup in ≤ 24 hours, compared to 1-2 months for on-site assembly). Please confirm that the module meets the transportation/lifting requirements.

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