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LNG Pre Treatment
Gas Treatment & Drying

LNG Pre Treatment

Removing water, carbon dioxide, mercury, and trace contaminants from natural gas feed to LNG liquefaction trains using 13X molecular sieve and impregnated guard beds.

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The Challenge
LNG plants operate at minus 162 °C in the main cryogenic exchanger; trace water and carbon dioxide freeze on the exchanger and force a costly defrost campaign, while trace mercury attacks the brazed aluminium and writes off the heat exchanger.
Quick Answer

LNG pre treatment removes the contaminants that would freeze, plug, or attack the cryogenic LNG train: water below 0.1 ppmv, carbon dioxide below 50 ppmv, mercury below 10 ng/Nm³. The duty uses 13X molecular sieve in a TSA cycle plus a downstream mercury guard bed of sulphur impregnated activated carbon.

LNG Pre Treatment

Cryogenic LNG Requires Ultra Clean Feed Gas

Natural gas liquefies at minus 162 °C in the main cryogenic heat exchanger of an LNG plant. Every part per million of water or carbon dioxide in the feed freezes against the exchanger surface and progressively blocks the gas passages; the operator faces a costly defrost campaign within months unless the pre treatment train delivers below 0.1 ppmv water and below 50 ppmv carbon dioxide reliably across the campaign life. Trace mercury attacks the brazed aluminium plate fin construction and can write off a heat exchanger worth tens of millions of dollars within years.

The SorbiTech LNG pre treatment train combines amine sweetening (where CO₂ is high), molecular sieve dehydration and polishing, and a dedicated mercury guard bed in a single integrated package.

Molecular Sieve TSA on the Front End

After the amine contactor the gas still carries 0.5 to 2 mol percent CO₂ and water at the saturation point. A SorbiTech 13X molecular sieve bed in a twin or triple tower TSA cycle drives the water to below 0.1 ppmv and the CO₂ to below 50 ppmv. The 13X grade is preferred over 4A because the 10 Å pore admits both water and CO₂ in the same bed, eliminating the two stage train.

LNG Pre Treatment process equipment

Mercury Guard Bed and Final Polishing

Downstream of the molecular sieve, a mercury guard bed of sulphur impregnated activated carbon captures elemental and ionic mercury as mercury sulphide. The outlet meets the cold box specification of below 10 ng/Nm³ mercury. The bed is single use and sized for the operator turnaround interval, typically 3 to 5 years for sweet gas service.

Delivery and Project Execution

Delivered turnkey by SorbiTech with full integration into the LNG plant licensor process (APCI, ConocoPhillips, Shell DMR, Linde). The SorbiTech media supply chain is locked to the project schedule, and the SorbiTech vessel fabrication runs to the operator approved drawing standard. Sector coverage is oil and gas.

Selection Guidance

Use 13X molecular sieve (combined water plus CO₂ removal) ahead of the cold box, then a sulphur impregnated carbon mercury guard bed. The bed is sized for the contracted campaign length, typically 3 to 5 years between media changeouts.

How SorbiTech Solves It

A Specified, Verified Solution

Define the duty

We capture your process conditions: flow, composition, pressure, temperature, and the target outlet specification.

Select media & configuration

Our engineers recommend the adsorbent grade and system type that meet the duty with margin.

Size & engineer

Bed sizing, vessel design, and cycle parameters are engineered to your case and documented for approval.

Commission & verify

We support loading, start up, and performance verification against the guarantee.

Recommended Products & Systems

Media

Adsorbents & Media

  1. 01 Molecular Sieve 13x Adsorbent Molecular Sieve 13X Sodium form 13X zeolite for cryogenic air pre purification and combined drying and sweetening. Pore Ø 10 Å
  2. 02 CMS 450hp Adsorbent Carbon Molecular Sieve CMS 450HP Ultra high purity carbon molecular sieve. 99.99999 percent (7N) N2, selective O2 and CO2 capture, 1.0 to 1.6 mm pellets, minimal fines, deoxo polishing… Water Cap. Feed must reach ISO 8573 class 1.4.1, deoxo polishing recommended for 7N %
  3. 03 CMS 420kt Adsorbent Carbon Molecular Sieve CMS 420KT High efficiency carbon molecular sieve. Higher oxygen affinity under 7 to 12 barg, 1.2 to 1.8 mm pellets, Snowstorm Filling compatible, ASTM D4058 attrition… Water Cap. Feed must reach ISO 8573 class 1.4.1 %
  4. 04 CMS 350kt Adsorbent Carbon Molecular Sieve CMS 350KT Rapid adsorption carbon molecular sieve. 40 to 90 second cycle at 7 to 10 barg, up to 99.99 percent N2, 1.0 to 2.2 mm… Water Cap. Moisture at supply below 1.0 percent, feed must reach ISO 8573 class 1.4.1 %
  5. 05 Activated Alumina Aa 201 Adsorbent Activated Alumina Impregnated Promoter loaded activated alumina for hydrogen sulphide, chloride, and Claus tail gas guard duty. Form 3–5 mm spheres · 1.6–3.2 mm spheres
  6. 06 CMS 260l Adsorbent Carbon Molecular Sieve CMS 260L Affordable carbon molecular sieve. 1.2 to 1.8 mm pellets, sub 10 Angstrom pore, 95 to 99.9 percent N2 from compressed air at 7 to… Water Cap. Intolerant of liquid water, feed must reach ISO 8573 class 1.4.1 %
Equipment

Engineered Systems

  1. 01 SorbiTech Mercury Guard Bed Hg Removal Sulphur Impregnated Carbon Equipment Mercury Guard Bed Sulphur impregnated activated carbon mercury guard bed for natural gas, condensate, and refinery streams to protect cryogenic and brazed aluminium equipment from mercury attack. Capacity 0.1–500 MMSCFD
  2. 02 SorbiTech Transformer Breather Cartridge System Silica Gel Grid Utility Breather Equipment Transformer Breather Cartridge System Pre packaged stainless steel transformer breather cartridge with indicating silica gel for grid transformer moisture protection across the high voltage transmission and distribution network. Capacity 0.5–25 kVA transformer to 800 kV substation
  3. 03 SorbiTech Cryogenic ASU Pre Purification Package ASU Front End 13x Alumina TSA Towers Equipment Cryogenic ASU Pre Purification Package Front end TSA pre purification package for cryogenic air separation units removing water, carbon dioxide, and trace hydrocarbons before the cold box. Capacity 5,000–500,000 Nm³/h air
  4. 04 SorbiTech Biogas Upgrading Unit Biomethane PSA Carbon Molecular Sieve Equipment Biogas Upgrading Unit PSA biogas upgrading unit using carbon molecular sieve to separate carbon dioxide from methane and deliver grid quality bio methane from anaerobic digester biogas… Capacity 50–2,000 Nm³/h raw biogas
  5. 05 SorbiTech Oxygen Vpsa Package Industrial Oxygen Vpsa Steel Mill Blast Furnace Equipment Oxygen VPSA Package On site vacuum pressure swing adsorption (VPSA) oxygen generation package delivering 90 to 95 percent oxygen for medical, aquaculture, ozone generation, and metals applications. Capacity 50–2,500 Nm³/h O₂ (90–95 % purity)
  6. 06 SorbiTech Heatless Desiccant Air Dryer Compressed Air ISO 8573 Twin Tower Dryer Equipment Heatless Desiccant Air Dryer Twin tower heatless desiccant compressed air dryer using activated alumina or silica gel for instrument and process air to pressure dew points below minus… Capacity 50–10,000 Nm³/h
Industries

Industries Using This Application

  1. 01 SorbiTech Industrial Gas Air Separation ASU Cryogenic Distillation Cold Box Sector Industrial Gas & Air Separation Molecular sieves and carbon molecular sieve plus PSA/TSA systems for nitrogen and oxygen generation and cryogenic air separation pre purification.
  2. 02 SorbiTech Oil Gas Offshore Platform Upstream Production Sector Oil & Gas Complete dehydration, separation, and treatment across upstream, midstream, and downstream oil and gas. SorbiTech supplies the adsorbent media and the engineered systems from one…

Specify a Solution for This Application

Provide your process conditions and our team will recommend the grade, configuration, and sizing.

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