Natural Gas Processing & Liquefied Natural Gas (LNG)

Cryogenic natural gas processing plants, liquefied natural gas plants (LNG) and fractionation plants depend upon molecular sieves to remove water and other contaminants to very low levels in both gas and liquid phase streams. Zeochem offers a wide range of long-lasting molecular sieve zeolite products for natural gas dehydration and treating to meet final quality specifications for pipeline, natural gas liquids (NGL), fractionation liquid products (propane, butane, isobutane, pentane, isopentane, hexanes+) and liquefied natural gas (LNG). Our molecular sieve products effectively remove water, hydrogen sulfide, mercaptans, oxygenates and carbon dioxide contaminants during gas processing and treating.

Cryogenic plants that use turbo-expansion technology to recover hydrocarbon liquids utilize Zeochem molecular sieves to protect downstream equipment by consistently drying their natural gas to less than 0.1 ppmv to prevent ice formation and the resulting pressure drop. Natural gas and LNG plants worldwide utilize Zeochem molecular sieves to purify the hydrocarbon stream, beyond simple dehydration, by removing sulfurs and oxygenates to meet product specifications. Our robust molecular sieve products reliably maintain protection for downstream equipment and consistently allow our customers to meet product specifications over the course of the complete service life of the adsorbent.

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Applications

Dehydration of Hydrocarbon Gas and Liquid Streams

Zeochem offers a range of long-lasting molecular sieve products for removal of water from natural gas and liquid hydrocarbon streams. These products are used to meet dew point specifications for pipeline, NGL, fractionation liquid (LPG, condensate, propane and butane) and LNG specifications. Zeochem products are effectively used in plants worldwide to consistently remove water to less than 0.1 ppmv levels with predictable and reliable performance. Our robust molecular sieve products maintain protection for plants' specifications over the course of the lengthy usable life of the adsorbent in both vapor and liquid phase applications.

Zeochem’s Z4-04 molecular sieve is a standard grade of the 4A type zeolite that can be used for dehydration of hydrocarbon gas and liquid streams where potential co-adsorption of other contaminant molecules, such as hydrocarbons, carbon dioxide and sulfur contaminants, is not a concern or issue. If H2S and CO2 are present in the stream, the formation of COS can occur. To avoid COS formation, Zeochem offers alternative products that will minimize this occurrence. Zeochem Z4-04 is normally regenerated at a temperature of 550°F (288°C) with a typical range of 500–600°F (260–315°C).

Zeochem’s Z3-06 molecular sieve is a form of the 3A type crystal that has unique properties and value for dehydration of hydrocarbon gas and liquid streams in specific applications and units. This and other products in Zeochem’s 3A family have the advantage of excluding other molecules from the internal crystal lattice while still adsorbing water. By limiting penetration and co-adsorption of molecules such as hydrocarbons, carbon dioxide and sulfur contaminants, the product and regeneration streams have a more consistent and predictable composition. This minimizes spiking of contaminants in these streams, which could potentially cause off-specification product or an inability to dispose of the spent regeneration gas. In addition to limiting hydrocarbon penetration and co-adsorption, Zeochem’s 3A molecular sieves allow lower regeneration temperatures, normally heating at a temperature of 450°F (232°C), with a typical range of 400–500°F (204–260°C).

Sulfur Removal

Zeochem offers select 5A and 4A type zeolite molecular sieve products for removal of sulfur from natural gas and liquid hydrocarbon streams. These products are used to meet final pipeline, NGL, fractionation liquid (LPG, condensate, propane and butane) and LNG specifications for hydrogen sulfide, mercaptans and overall sulfur content. Sulfur compounds can be removed upstream in the vapor phase dehydration unit in some cases, or downstream in liquid phase treaters. Zeochem products are effectively used in plants worldwide to consistently remove sulfur compounds to ppm levels with predictable performance. Our robust molecular sieve products maintain protection for plants' specifications over the course of the lengthy usable life of the adsorbent in both vapor and liquid phase applications.

Zeochem’s family of 5A type molecular sieve zeolites can remove sulfur species that are approximately 5 angstroms or less in kinetic diameter. These products have excellent physical and kinetic properties, along with hydrothermal stability when adsorbing water and sulfur compounds in regenerative applications. They are recommended when removal is limited to hydrogen sulfide, methyl mercaptan and ethyl mercaptan. Zeochem’s product line includes a product specially developed for the minimization of carbonyl sulfide (COS) formation when hydrogen sulfide and carbon dioxide are present.

Zeochem’s family of 13X type molecular sieve zeolites can remove sulfur species that are approximately 10 angstroms or less in kinetic diameter. These products have the highest adsorption capacity and fastest kinetics for the removal of impurities and are often recommended when further optimization is needed. With their large crystal pore openings and open pore structure, they are ideally suited for removal of the larger sulfur species, such as propyl and butyl mercaptans, from natural gas and hydrocarbon liquids. By contrast, other molecular sieves cannot adsorb them due to their smaller size.

Oxygenate Removal

Zeochem offers a range of proven molecular sieve products for removal of oxygenates from natural gas and liquid hydrocarbon streams. Zeochem products are effectively used to remove impurities such as alcohols, ethers and ketones, as well as other oxygenates from vapor and liquid streams. Our robust molecular sieve products are used to maintain product, process and catalyst integrity over their useful lives. Specific products are recommended by our technical experts based upon the type of oxygenate species to be removed and the stream composition.

Zeochem’s family of 13X molecular sieve zeolites are the most widely recommended products, finding applicability for most applications requiring oxygenate removal. These products provide the best removal efficiency, the highest capacity for oxygenates and the largest range of impurities that can be removed. These products have large crystal pore openings of approximately 10 angstroms and an open pore structure, giving them excellent equilibrium and dynamic performance, which allows both large and small oxygenate molecules to be removed from gas and liquid hydrocarbon streams. Zeochem 13X molecular sieves typically regenerate at a temperature of 550°F (288°C) in this application, but the acceptable range is 450–600°F (232–315°C) depending on the oxygenates and the amount of water present.

Zeochem’s 4A molecular sieves, as well as our 5A molecular sieves are effective for the removal of smaller oxygenates such as methanol and ethanol and provide an alternative choice to Zeochem 13X when higher capacities may not be necessary. In applications where water as well as alcohol removal is required, a separate layer of Zeochem’s 3A molecular sieve can be used for removal of water to minimize regeneration temperature, utilizing a normal temperature of 450°F (232°C) with a typical range of 400–500°F (204–260°C).

Let our dedicated experts guide you through the selection process to determine which molecular sieve would be best in your application.

Carbon Dioxide Removal

Zeochem offers a select range of long-lasting molecular sieve products for removal of carbon dioxide from natural gas. These products are used to meet required specifications and processing requirements for NGL and LNG production. Zeochem products effectively and consistently remove carbon dioxide from vapor phase streams to meet typical requirements of less than 50 ppmv and in some cases even lower, with predictable, consistent performance. The regeneration temperature can generally be lower for this service, with a typical range of 400–550°F (204–288°C), depending on the amount of water and other impurities present in the stream.

Zeochem’s 13X molecular sieves serve as the primary choice for the most effective removal of CO2 from light hydrocarbon gas streams. These products are used in peak shaving applications for removal of CO2 concentrations up to 3% and in small-scale LNG projects. In some new small-scale projects, these adsorbents may be used in a specialized setup to avoid the need for an upstream amine system and with minimized regeneration volume requirements.

Zeochem’s 5A molecular sieves also have good carbon dioxide removal ability and serve as very capable alternative options. They are the primary recommendation when hydrogen sulfide and carbon dioxide are present, and the formation of carbonyl sulfide (COS) is to be avoided. These products have excellent physical properties and adsorption kinetics.

Related Products

Zeochem offers a broad range of molecular sieve products ideally suited to each natural gas, LNG and fractionation plant adsorbent application. From dehydration of natural gas to protect downstream cryogenic equipment to final sulfur and oxygenate removal from liquid hydrocarbon streams to meet product specifications, Zeochem products are specialized for reliable operation in a wide range of applications.

3A

3A is made by ion-exchanging the sodium in type 4A zeolite with potassium. The 3A molecular sieve will exclude most molecules except water, making it very selective.

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4A

4A is the sodium form of the type A zeolite molecular sieve and is widely used as a general purpose drying agent. Under certain conditions, it can also be used for removal of ammonia, alcohols, carbon dioxide, H2S and other specific molecules.

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5A

5A is the calcium-exchanged form of the type A zeolite molecular sieve and is primarily used for removing carbon dioxide, carbon monoxide, alcohols and other oxygenates, hydrogen sulfide, methyl and ethyl mercaptans, and others.

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13X

Type 13X offers enhanced adsorption properties and the ability to remove impurities too large to be adsorbed by the type A zeolites.

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Activated Alumina

Activated alumina adsorbent is an effective bed-topping layer used as a protective layer, at the inlet of gas-phase molecular sieve beds.

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Custom Solutions

Let our technical service experts with their decades of experience guide you through product selection and then customize a technical design with vessel sizing, regeneration flow and operational sequencing. Whether you are seeking pipeline-quality methane, extraction of natural gas liquids or liquefaction of natural gas, our experienced team and quality products will help you run reliably, efficiently and predictably.