Room Temperature Purification


Introduction

This section presents briefly the different types of helium gas purification systems operating at room temperature levels. Depending on the purity level needed, the Quantum team will design the most efficient system for your application.


Purification Technologies


1. PSA – Pressure Swing Adsorption

The PSA technology uses molecular sieves (adsorbents) in order to separate the impurities from the helium gas through the selective adsorption process. Quantum produces PSA helium purification systems for applications where the helium gas contains contaminants such as carbon dioxide, oxygen, nitrogen or hydrocarbons. These impurities are adsorbed by the molecular sieve, which is subsequently regenerated at low pressures (of the order of a few psig). The advantages of this technology are a relatively low power necessary to operate the system and the relatively easy shutdown/startup of the system, making it attractive for irregular use.


The size of the system will depend on the customer needs, and the resulting helium gas is at high purity – 99.99% and above.


Potential ranges for the different gas streams:


Feed Gas

  • Incoming Helium purity: from 20% or less to 95% or above
  • Pressure: 40 to 350 psig
  • Temperature: 5 to 45°C

Helium out of the PSA

  • Flow rates: a wide range, as per customer process
  • Pressure drop: <10 psi
  • Helium purity: above 99.99%

2. TSA – Temperature Swing Adsorption

The TSA technologies use temperature to regenerate the molecular sieve when the level of impurities reaches a certain limit. Typical regeneration temperatures could reach 125 degrees C and above. The TSA technology requires in general a higher CAPEX, however it is more cost effective when the feed gas pressure is low, generally below 3-5 barg.


The TSA purification systems can reach high helium purities – above 99.99%.


3. Membrane Systems

The membrane systems utilize the permeability property of certain polymers. The impurities (such as air, carbon dioxide, etc.) are not permeating through the membrane, while helium does. The membrane systems are accompanied by a compressor generating sufficient pressure to ensure the optimal separation of the helium gas from the impurities. The tuning of such a simple yet efficient purification process is part science – part experience.


The membrane purification systems can lead to helium purities in excess of 99%.


Bottom Line

While there are many methods of purifying helium, there is only one method which best applies to your process. Please contact us in order to assist you with the most reliable, yet cost effective design.