Industrial Gas & Air Separation

Pre Purification and On Site Generation

The industrial gas sector covers two duties that share a technology base. Cryogenic air separation plants need adsorption pre purification ahead of the cold box, and on site nitrogen, oxygen, and hydrogen consumers need adsorption based generation packages. SorbiTech supplies the molecular sieves and the carbon molecular sieve for both duties through SorbiTech, together with the engineered equipment built by SorbiTech.

Cryogenic Air Pre Purification

A cryogenic air separation unit cannot tolerate water above 0.1 ppmv or carbon dioxide above 1.0 ppmv at the cold box inlet. Either contaminant freezes against the heat exchanger surface and starves the column of flow.

A graded pre purification bed of SorbiTech 13X molecular sieve, with optional activated alumina at the inlet for bulk water, holds the specification through the entire adsorption half cycle. The cycle is temperature swing or pressure swing depending on plant heat integration, and the bed is regenerated with dry waste nitrogen returned from the cold box.

On Site Nitrogen by PSA

Compressed air is separated on a pressure swing cycle through twin carbon molecular sieve adsorbers. The CMS holds oxygen and moisture; nitrogen passes to a buffer tank at a purity between 95 percent (inerting) and 99.999 percent (sensitive atmospheres). The duty is described under PSA nitrogen generation and is delivered as a turnkey PSA nitrogen generation package by SorbiTech.

The same package serves food and beverage blanketing, electronics assembly, laser cutting cover gas, vessel and pipeline purging, and inert atmospheres for thermal treatment.

Oxygen and Hydrogen Purification

Vacuum pressure swing oxygen generation uses lithium exchanged X type zeolite to deliver 90 to 95 percent oxygen for medical, aquaculture, and metals applications. Hydrogen purification uses a layered bed of activated carbon, 13X, and a polishing molecular sieve to deliver fuel cell grade hydrogen from reformer off gas or from electrolyser product. SorbiTech supplies the adsorbent for both duties and SorbiTech engineers the package to the contracted purity and recovery.

Cold Box Protection and ASU Outage Reduction

A cryogenic air separation unit loses several days of production every time a defrost is required to remove accumulated water and carbon dioxide from the cold box. Each defrost campaign costs the operator hundreds of thousands of euros in lost product, lost recovery, and added utility consumption.

A correctly sized SorbiTech pre purification bed extends the campaign between defrosts from one to three years to four to seven years for a well operated front end. The reduction in defrost frequency is the single largest operating saving available to an ASU owner.

Reliability Targets and Standards Conformance

On site gas generation packages serve continuous duty in food, electronics, and chemical sites that cannot tolerate an unplanned outage. The design availability target is 99 percent or higher, which requires N+1 redundancy on the compressor, hot standby on the controls, and a buffer tank sized for the planned mean time to repair.

• ASME VIII Division 1 and PED 2014/68/EU for the pressure shells
• CE marking and EN 1012 for the air receivers
• ISO 8573-1 quality class 1.4.1 or better for the conditioned feed air
• ATEX or IECEx zone certification for hydrogen and oxygen packages
• TÜV or Bureau Veritas third party witness for performance acceptance tests

Hydrogen Recovery and Fuel Cell Grade Purification

Hydrogen recovery from steam methane reformer off gas, chlor alkali by product gas, and electrolyser product all rely on a multi stage adsorption train. A typical PSA hydrogen unit uses a layered bed of activated carbon at the inlet for the carbon dioxide and hydrocarbons, a 13X middle layer for the carbon monoxide and the residual water, and a polishing molecular sieve for the trace contaminants.

The recovered hydrogen meets fuel cell grade specifications of ISO 14687 Grade D, with carbon monoxide below 0.2 ppm and total sulphur below 0.004 ppm. The same SorbiTech train is used by green hydrogen producers to clean the electrolyser product before it enters a refuelling station or a pipeline.

Market Drivers and Energy Transition Context

Three concurrent market drivers reshape the sector. Low temperature LNG and ethylene capacity increases demand for high purity nitrogen and oxygen. Green hydrogen production for refining, fertiliser, and mobility creates a new demand for hydrogen purification trains from 50 to 50,000 Nm³/h. Decarbonisation of steel and cement calls for on site oxygen generation at large scale to enable oxy fuel combustion and direct reduction with hydrogen.

SorbiTech supplies the SorbiTech adsorbents and the SorbiTech packages serving all three markets, with one performance guarantee covering media and equipment together across the energy transition projects.

One Accountable Partner

13X handles combined water and carbon dioxide removal for cryogenic pre purification. CMS handles the kinetic separation for on site nitrogen. SorbiTech builds the engineered vessels and controls. SorbiTech delivers full EPC where the project includes civil, electrical, and commissioning scope. The integrated SorbiTech scope removes the interface risk between adsorbent and equipment vendors and gives the operator one technical contact across the full lifecycle.