Sepcor Dessicants for Air Brakes

Molecular Sieves, Silica Gels, Alumina to dehydrate gases in air brakes


Air Brakes


A PSA  (Pressure Swing Adsorption) dryer, typically a single packed bed of molecular sieve is used to dry the compressed gas on air brake systems in trucks or trains. Dry air is supplied to the brakes to prevent the unintended the brakes employing while the truck is moving. SEPCOR can provide the molecular sieve adsorbent that will fit this service.


Pressure Swing Adsorption (PSA) is a technology that is used to separate some species from a gas under pressure according to these species' molecular characteristics and affinity for an adsorbent material. It operates at near-ambient temperatures and so differs from cryogenic distillation techniques of gas separation. Special adsorptive materials (e.g., zeolites) are used as a molecular sieve, preferentially adsorbing the undesired gases at high pressure. The process then swings to low pressure to desorb the adsorbent material.


Using two adsorbent vessels allows near-continuous production of the target gas. It also permits so-called pressure equalization, where the gas leaving the vessel being depressured is used to partially pressurize the second vessel. This results in significant energy savings, and is common industrial practice.


One application of PSA is the separation of carbon dioxide (CO2) from biogas to increase the methane (CH4) content. Through PSA the biogas can be upgraded to a quality similar to natural gas.


Research is currently underway for PSA to capture CO2 in large quantities from coal fired power plants prior to geo-sequestration, in order to reduce greenhouse gas production from the SE plants.


PSA is an economic choice for small-scale production of reasonable purity oxygen or nitrogen from air. PSA technology has a major use in the medical industry to produce oxygen, particularly in remote or inaccessible parts of the world where bulk cryogenic or compressed cylinder storage are not possible.