Vapor Adsorption Cartridges

Description

We offer a complete line of disposable adsorption cartridges filled with desiccant media for moisture removal, as well as adsorbents designed for surface binding of contaminant gases within process streams.  Vapor adsorption cartridges incorporate inner and outer filter elements rated 99.99% efficient at 0.01 micron. The adsorption media is securely sandwiched between these elements and fully encapsulated with bonded end caps to ensure zero media migration. Cartridges are designed to fit our standard housings for easy installation and replacement, providing a clean, disposable solution with no loose media handling.

Vapor adsorption cartridges are constructed with concentric inner and outer support tubes, forming a uniformly packed annular volume of adsorbent media. The assembly is sealed with bonded end caps and incorporates positive O-ring seals at both ends to prevent bypass, maintaining system integrity.

Nominal flow rates are equivalent to those of a disposable Grade 50 filter element of the same physical size. In adsorption applications, however, performance is governed primarily by adsorbent volume and contact (residence) time, rather than flow capacity alone.

For point-of-use, tube-connection applications, we also offer Disposable In-line Adsorbers (DIA), available with encapsulation in nylon or Kynar®.

(*)    Headline’s CC Adsorption Cartridges are constructed entirely of highly adsorbent fibrous activated carbon formed into a strong, flexible cloth. This carbon cloth provides significantly greater dynamic adsorption capacity than granular carbon or carbon-impregnated media.

Unlike conventional charcoal materials, the carbon cloth maintains performance in moist conditions, exhibiting far less degradation when exposed to humidity. To prevent carbon dust carryover, the carbon cloth is fully encapsulated on both the upstream and downstream sides with a high-efficiency borosilicate glass microfiber layer.

For optimal performance and service life, carbon cloth adsorbers should be protected by 70C and 50C coalescing prefilters. Under typical operating conditions, activated carbon can adsorb approximately 20–30% of its own weight in contaminants.

The following factors should be considered when designing a system that incorporates vapor adsorption cartridges:

1. Phase Compatibility (Vapor vs. Liquid)
   Adsorbents are effective only for vapor-phase contaminants. Exposure to liquids will damage or deactivate most solid adsorbents. Therefore, adsorption cartridges or DIAs must be protected upstream by an efficient coalescing filter (e.g., Grade 70C or 50C) to remove entrained liquids and aerosols.

2. Finite Adsorption Capacity and Breakthrough Behavior
   Unlike microfiber filters, which operate at essentially constant efficiency throughout their service life, adsorption cartridges have a finite holding capacity. Once this capacity is reached, additional adsorption does not occur. The limiting capacity, commonly referred to as the breakthrough point, is not sharply defined; instead, outlet vapor concentration rises rapidly as saturation is approached.

To prevent downstream contamination, adsorption cartridges must be replaced well before reaching full saturation. Determining the appropriate change-out point is application-specific and depends on multiple variables. As a general rule of thumb, many adsorbents can retain approximately 20% of their own weight in adsorbed vapor (see Item 3).

3. Adsorption Efficiency and Operating Conditions
   The adsorption efficiency of a given adsorbent for a specific vapor is highly dependent on operating conditions. Consequently, unlike filtration, adsorption media cannot be assigned a single, fixed efficiency rating. In addition to the intrinsic affinity between the adsorbent and the target vapor, key influencing factors include:
   • Temperature – Adsorption efficiency generally increases as temperature decreases and decreases at elevated temperatures.
   • Vapor Concentration – Percentage removal efficiency is typically higher at low inlet vapor concentrations, whereas total adsorption capacity increases at higher vapor concentrations.
   • Contact Time (Residence Time) – Adsorption efficiency improves with increased contact time; therefore, the lowest practical flow rate should be maintained for optimal performance.
   • Presence of Competing Vapors – Adsorption of a target vapor is reduced in the presence of other vapors with affinity for the same adsorbent. For example, high concentrations of water vapor significantly reduce the adsorption of other vapors on carbon, silica gel, or molecular sieves.

4. Reversibility and Desorption Effects
   Adsorption is generally a reversible process. Changes in operating conditions may cause desorption rather than adsorption. This reversibility is intentionally exploited during adsorbent regeneration via heating, vacuum application, or purging with a low-contaminant gas stream. However, inadvertent desorption can also occur during normal operation. For example, a temporary increase in inlet vapor concentration may result in significant adsorption, followed by desorption if the inlet concentration subsequently decreases.

While adsorption efficiency cannot be precisely predicted or guaranteed for all operating conditions, system performance can be optimized by maximizing conditions favorable to adsorption and minimizing factors that inhibit or reverse the adsorption process.