{ CMS poisoning }

  • Five Types of CMS Poisoning Symptoms & Remedial Solutions

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           Carbon Molecular Sieve (CMS) is the core consumable of PSA nitrogen generators. Once poisoned, it leads to reduced nitrogen output, insufficient gas purity and rising air-to-nitrogen ratio, shortening service life significantly. The five common poisoning causes are water soaking, oil fouling, acid gas corrosion, high-temperature degradation and dust coking. Most operators only spot CMS pulverization while ignoring poisoning as the root cause. This article analyzes symptoms, causes and field solutions for each failure.

     

    Type of Poisoning

    Symptoms

    Causes

    Solution

    Water Flooding Poisoning

    Lower N₂ purity & output; CMS caking; higher air-nitrogen ratio

    Poor air drying; condensed water or moisture backflow

    Long-time no-load purging; hot air drying; repair pre-drying system

    Oil Contamination Poisoning

    Black & sticky CMS; permanent capacity drop; unable for 99.99% high purity

    Compressor oil leakage; failed pre-oil filtration

    Light pollution: high-temperature N₂ regenerationHeavy pollution: replace full CMS and filters

    Acid Gas Corrosion Poisoning

    Brittle CMS; more powder; higher tower pressure drop; low N₂ recovery

    Sulfide & acidic gas in raw air erodes carbon structure

    Replace corroded CMS; add activated carbon pre-filter

    High-Temperature Degradation Poisoning

    Fragile CMS; failed high-purity nitrogen production; performance decay

    Overheated inlet air (>45℃); poor heat dissipation

    Control inlet temperature at 20–35℃; replace thermally damaged CMS

    Dust Coking Poisoning

    High tower pressure difference; blocked pores; reduced gas yield

    Dust and organic residue coking inside micropores

    Screen and regenerate CMS; install intake dust filter

     

    In short, proper inlet air pretreatment against water, oil, acid and dust is the key to avoid CMS poisoning and keep long-term stable adsorption efficiency. Effective pre-treatment helps maintain consistent nitrogen purity and rated gas output, greatly extending the service cycle of carbon molecular sieve.