COS adsorbent

What Is a COS Adsorbent?

A COS adsorbent is an improved high-efficiency purification adsorbent catalyst based on specialty alumina as the carrier with active components. Its performance is equivalent to imported Selexsorb COS adsorbent. Due to strong chemical adsorption on its surface, it can selectively and directly remove trace amounts of COS, CS₂, and H₂S from cracked C₂–C₄ unsaturated hydrocarbon monomer streams. It also effectively removes CO₂, H₂O, chlorides, cyanides, and other common poisons, meeting the deep purification requirements for feedstocks. The product operates at ambient to low temperatures, making it ideal for cracking gas and olefin stream purification.

For a companion product covering oxygenate, water, and mercaptan removal in the same purification train, see our CD Adsorbent.

Composition & Structure

Active Components:

• Specialty Al₂O₃ carrier — High-surface-area alumina base providing excellent structural integrity and thermal stability
• Active components — Enhanced active components providing strong chemical adsorption affinity for sulfur compounds, CO₂, H₂O, chlorides, cyanides, and other poisons

Physical Form: The adsorbent is manufactured using a pebble-rolling process, producing uniform white spherical granules (Φ1.5–3.0 mm). This rounded shape ensures low pressure drop, uniform gas flow distribution, and excellent mechanical strength (≥ 40 N/particle) for industrial service.

Adsorption Mechanism

The adsorbent removes contaminants through strong chemical adsorption on its specially formulated surface:

1. Sulfur Compound Removal (COS, CS₂, H₂S):

• COS is adsorbed and hydrolyzed on the active surface: COS + H₂O → H₂S + CO₂, followed by chemisorption of H₂S
• CS₂ undergoes similar hydrolysis and adsorption
• H₂S is directly captured by active sites through acid-base reaction

2. Multi-Contaminant Capture:

• CO₂ is chemisorbed by basic active sites
• H₂O is captured by the alumina surface
• Chlorides and cyanides are adsorbed onto active metal sites

This multi-mechanism approach enables single-bed deep purification of cracked gas streams, removing multiple contaminants simultaneously.

Key Advantages

Selexsorb-Equivalent Performance:

• Performance comparable to imported BASF Selexsorb COS adsorbent
• Provides a cost-effective alternative with proven reliability

High Surface Area & Porosity:

• Surface area ≥ 260 m²/g provides abundant active sites
• Pore volume ≥ 0.35 ml/g ensures excellent diffusion and capacity

Low-Temperature Operation:

• Effective from 10°C to 120°C, suitable for ambient-condition processes
• No preheating required for most applications

Regenerable:

• Can be regenerated with N₂ (99% purity) for multiple service cycles
• Reduces operating costs and material waste

Selective for Olefin Streams:

• Specifically effective for C₂–C₄ unsaturated hydrocarbons
• Does not react with olefins — only targets contaminants

Reference Operating Conditions

Process Conditions:

• Temperature: 10–120°C
• Pressure: Atmospheric–6.0 MPa
• Space Velocity: Application-dependent

Feed Specifications:

• Suitable for cracked C₂–C₄ hydrocarbon streams
• Also applicable to LPG, syngas, hydrogen, and natural gas

Performance Output:

• Deep purification to trace contaminant levels
• CO₂ adsorption capacity ≥ 5 wt.%

Applications in Petrochemical & Refining

Cracked Olefin Purification (Primary Application): In steam cracking and catalytic cracking units, the C₂–C₄ product streams contain trace amounts of COS, CS₂, and H₂S. These sulfur compounds poison downstream polymerization catalysts (Ziegler-Natta, metallocene). The COS adsorbent serves as the guard bed, delivering product-spec purity olefins.

LPG & Light Hydrocarbon Treatment: Removes sulfur compounds and moisture from propane, butane, and mixed light hydrocarbons before storage or further processing.

FCC Off-Gas Cleanup: Purifies fluid catalytic cracking unit off-gas streams, removing sulfur and other contaminants before downstream processing or flaring.

Syngas & Hydrogen Conditioning: Multi-contaminant removal (COS, H₂S, CO₂, H₂O, chlorides) from synthesis gas and hydrogen streams in ammonia and methanol production units.

Alkylation & MTBE Feed Polishing: Eliminates COS, H₂S, and chlorides from alkylation and etherification feedstocks, protecting acid catalysts from deactivation.

Many buyers pair this product with our CD Adsorbent for full-spectrum guard bed protection ahead of polymerization reactors — read more in our COS adsorbent guide. For polymer-grade ethylene or propylene feed specifically, the purification train typically extends to a final CO removal stage — see our Ethylene Purification Adsorbent or Propylene Purification Adsorbent depending on your monomer.

Service Life & Regeneration

Service Life: The adsorbent operates on a chemisorption mechanism. Service life depends on:

• Inlet contaminant concentrations (COS, CS₂, H₂S, CO₂, etc.)
• Operating temperature and pressure
• Space velocity and feed flow rate
• Required outlet purity specification

Typical service life ranges from 6 months to 2 years, depending on operating conditions.

Regeneration: The adsorbent can be regenerated using N₂ (99% purity) purge gas. Regeneration restores a significant portion of adsorption capacity, allowing multiple service cycles. The number of regeneration cycles depends on the severity of contamination and operating conditions.

Why Choose Our COS Adsorbent?

1. Selexsorb-Equivalent Performance

Delivers purification performance comparable to imported BASF Selexsorb COS adsorbent at a competitive cost.

2. Multi-Contaminant Removal in One Bed

Simultaneously removes COS, CS₂, H₂S, CO₂, H₂O, chlorides, and cyanides — replacing what would otherwise require multiple purification stages.

3. Low-Temperature Operation

Effective from 10°C, eliminating the need for feed preheating in most applications.

4. High Surface Area & Capacity

≥ 260 m²/g surface area and ≥ 0.35 ml/g pore volume ensure high contaminant capacity and extended service life.

5. Regenerable & Cost-Effective

Can be regenerated with N₂ for multiple cycles, reducing operating costs and material waste.

6. Selective for Olefin Streams

Specifically effective for C₂–C₄ unsaturated hydrocarbons without reacting with olefins.

7. Customizable Supply

Composition and particle size can be adjusted to match specific process requirements. Contact our technical team for tailored solutions.

Packaging & Shipping

We offer secure packaging and flexible shipping options for bulk industrial orders.

Standard Packaging:

• 25 kg sealed steel drums with inner double-layer plastic bags (moisture-proof, suitable for trial orders and small batches)
• 40 kg sealed steel drums with inner double-layer plastic bags (standard packaging for bulk orders)
• Custom packaging available on request

Minimum Order Quantity (MOQ):

• 1 ton (entry-level orders accepted — ideal for first-time customers)
• 5+ tons (standard bulk orders)
• Container-level supply for long-term partnerships

Container Loading Capacity:

• 20'GP container: 18-20 tons (palletized)
• 40'GP container: 22-24 tons (palletized)
• 40'HQ container: 24-26 tons

Loading Ports: We ship from major Chinese ports based on your requirements: Shanghai, Qingdao, Tianjin, Ningbo, and Shenzhen.

Lead Time:

• Stock orders: 7-15 days from payment confirmation
• Made-to-order: 20-30 days

Shipping Terms: FOB / CIF / CFR / EXW — flexible based on your destination and preferences.

Storage: Store in a cool, dry, well-ventilated area. Protect from moisture, chemical contamination, and physical impact. Keep sealed until loading. Shelf life exceeds 3 years when stored properly in original unopened packaging.

Handling: Use appropriate personal protective equipment (PPE) when handling. Avoid inhalation of dust and contact with skin or eyes. Sieve before loading to remove fines.

Documents & Certificates

We provide complete documentation for every order:

📄 Technical Data Sheet (TDS) — Confirmed with you during product selection, ensuring exact specifications match your application requirements.

📄 Safety Data Sheet (SDS) — Provided before shipment, meeting all international transportation and handling standards.

📄 Certificate of Analysis (COA) — Issued for each production batch, delivered with your shipment for full quality traceability.

Additional documents available on request: Certificate of Origin (COO), Packing List, Commercial Invoice, Third-party Inspection Report (SGS / BV), Form E (for Middle East destinations with applicable tariff benefits).

FAQ

Q1: What is the difference between this COS adsorbent and imported Selexsorb? A: Our COS adsorbent delivers equivalent purification performance to BASF Selexsorb COS, using specialty alumina with active components. It provides a cost-effective alternative with proven reliability in industrial applications.

Q2: What contaminants does this adsorbent remove? A: It selectively removes COS, CS₂, H₂S from cracked C₂–C₄ streams, and also effectively removes CO₂, H₂O, chlorides, cyanides, and other common poisons.

Q3: What are the typical operating conditions? A: Temperature 10–120°C, pressure atmospheric to 6.0 MPa. The adsorbent is effective at ambient temperature, making it suitable for low-temperature processes.

Q4: Can this adsorbent be regenerated? A: Yes, the adsorbent can be regenerated using N₂ (99% purity) purge gas, allowing multiple service cycles and reducing operating costs.

Q5: What is the CO₂ adsorption capacity? A: The CO₂ adsorption capacity is ≥ 5 wt.%, providing effective CO₂ removal from process streams.

Q6: What applications is this adsorbent suitable for? A: It is widely used for cracked C₂–C₄ olefin purification, LPG treatment, FCC off-gas cleanup, ammonia/methanol plant feed conditioning, and alkylation/MTBE feed polishing.

Q7: What is the physical form and mechanical strength? A: White spherical granules, Φ1.5–3.0 mm diameter, bulk density 0.70–0.85 kg/L, crush strength ≥ 40 N/particle. The pebble-rolled spherical shape ensures low pressure drop and uniform gas flow.

Need a Custom Solution?

For bulk pricing and grade recommendation, please send your feedstock composition & operating conditions to us. Our technical team will get back to you within 24 hours with a tailored solution.

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