Demand for compressed air quality in the chemical industry

The chemical industry’s demand for compressed air quality involves multiple key dimensions, and its standard formulation must strictly follow production process requirements and equipment safety regulations. The following is a systematic interpretation based on industry practice:

1. Core quality indicators and industry requirements

1. cleanliness control
   • Particulate matter restriction: According to the GB/T 13277.1-2023 standard, the chemical industry usually requires that the content of particulate matter above 0.1μm in compressed air be less than 0.1 mg/m³, which is equivalent to the ISO 8573-1 Class 1 standard. In precision synthesis reactions, the concentration of particulate matter needs to be further controlled below 0.01mg/m³.
   • Microbial control: For the pharmaceutical and biochemical fields, a 0.22μm level sterilization filter needs to be added to ensure that the microbial content of compressed air is less than 1CFU/m³.
2. dryness criterion
   • dew point temperature: Conventional processes require compressed air pressure dew point ≤-40℃ (equivalent to water vapor content ≤127.34ppmv), and in low-temperature reaction processes, it needs to reach-70℃ (water vapor content ≤2.598ppmv).
   • condensation control: In the pipeline transportation process, the compressed air temperature is required to always be 5-8 ° C higher than the ambient temperature to prevent the formation of condensed water.
3. Oil content control
   • total oil content: General process requirements are ≤0.01mg/m³ (ISO 8573-1 Class 1), and oil-free standards (≤0.003mg/m³) must be met in catalyst preparation, polymer polymerization and other processes.
   • Oil vapor control: Adopt activated carbon adsorption or catalytic oxidation technology to ensure that the oil vapor concentration is less than 0.001ppm.

2. Process adaptability requirements

1. pressure stability
   • The flow fluctuation range should be controlled within ±3%, and the pressure fluctuation should be ≤0.05MPa. In high-pressure processes such as hydrogenation reactions, a special pressure stabilizing device needs to be equipped to ensure pressure stability of <±1%.
   • Equipped with a pressure buffer tank, the volume is designed to meet the maximum air consumption reserve of 10 minutes.
2. temperature resilient
   • The compressed air temperature needs to be controlled below 40℃, and an aftercooler needs to be configured in the high-temperature reaction process to ensure that the outlet temperature is ≤ the ambient temperature +15 ℃.
   • Low-temperature transmission pipelines need to adopt an electric heat tracing system to maintain the pipe wall temperature> the dew point temperature of 5℃.

3. Safety and environmental protection requirements

1. Gas purity guarantee
   • In the processing of flammable and explosive materials, an oxygen content analyzer needs to be equipped to ensure that the oxygen volume fraction in the compressed air is less than 2%.
   • For toxic gas delivery systems, a dual-stage leak alarm device needs to be set up with a response time of <2 seconds.
2. emission control
   • Backblown gas and sewage gas need to be adsorbed by activated carbon to ensure that the emission concentration of non-methane total hydrocarbons is less than 60mg/m³.
   • Condensate water needs to be treated by an oil-water separator and can be discharged only after the oil content is ≤5ppm.

4. Differences in demand for typical process scenarios

1. polymerization process
   • Need to be equipped with a dedicated oxygen removal system, with oxygen content <1ppm
   • Dew point temperature ≤-60℃
   • Particle size <0.01μm
2. gas delivery system
   • Pressure stability <±0.02MPa
   • Equipped with online moisture analyzer, response time <3 seconds
   • Pipe inner wall roughness ≤Ra0.4μm
3. instrument control system
   • Three-level filtration system needs to be configured (accuracy 1μm→0.01μm→0.001μm)
   • Pressure fluctuation <±0.01MPa
   • Dew point temperature ≤-40℃

V. Quality assurance system

1. specification for testing of
   • Daily testing items: pressure, temperature, dew point
   • Weekly testing items: oil content, particulate matter concentration
   • Monthly testing items: microbial content, oxygen content
2. Equipment configuration requirements
   • Pre-filter: 5μm accuracy, filtration efficiency>99%
   • Precision filter: 0.01μm accuracy, filtration efficiency>99.999%
   • Adsorption dryer: dew point temperature can reach-70℃
   • Zero-level oil-consuming air compressor: residual oil amount <0.003mg/m³

The compressed air system in the chemical industry needs to establish a full life cycle management system to form a closed-loop quality control from air compressor selection, pipeline design to terminal air equipment. It is recommended to configure an intelligent monitoring system to collect pressure, flow, dew point and other parameters in real time, and warn potential risks through data analysis to ensure that the quality of compressed air continues to meet process requirements.