Product Description
CD Adsorbent: High-Efficiency Purification Adsorbent for Olefin Processing
Product Overview
CD Adsorbent is an advanced, high-efficiency purification adsorbent catalyst engineered for deep purification of olefin feedstocks in polyethylene and polypropylene production facilities. Built on a specialized alumina carrier with proprietary modifying agents, this adsorbent delivers performance equivalent to leading imported alternatives such as selexsorb CD, providing a cost-effective domestic solution without compromising purification efficacy.
Designed to operate efficiently under both ambient and low-temperature conditions, CD Adsorbent leverages strong chemisorption mechanisms to selectively remove trace oxygenate impurities from C₂–C₄ hydrocarbon streams. These impurities—including alcohols, ethers, aldehydes, carboxylic compounds, ketones, and peroxides—can severely impact catalyst performance and product quality in polyolefin manufacturing. Beyond oxygenates, the adsorbent also effectively removes water and mercaptans, ensuring comprehensive feedstock purification that meets demanding industry standards.
With its dual patented active components and optimized pore structure, CD Adsorbent achieves ppb-level purification precision, protecting downstream polymerization catalysts and ensuring consistent production of high-quality polyolefin products. It addresses a critical need in the petrochemical industry: reliable, high-performance purification that reduces dependency on imported specialty adsorbents.
Technical Principle
Specialized Alumina Carrier
At the core of CD Adsorbent lies a specially formulated alumina (Al₂O₃) carrier engineered for optimal adsorption performance. Manufactured through precise process control, the carrier achieves a high specific surface area of 380 m²/g and pore volume of at least 0.35 ml/g. This tailored porous structure provides abundant active sites for impurity capture while ensuring efficient mass transfer. The spherical morphology (1.5–3.0 mm diameter) enhances flow distribution and reduces bed pressure drop.
Chemisorption Mechanism
CD Adsorbent operates primarily through chemisorption, distinguishing it from conventional physical adsorbents relying on van der Waals forces. The strong chemical bonding between active sites and oxygenate impurities enables highly selective removal even at extremely low concentrations. This mechanism provides higher selectivity for polar oxygenates over non-polar hydrocarbons, greater low-concentration capacity, and resistance to desorption under varying process conditions. The result is deep purification with outlet methanol below 0.5 ppm and water below 1 ppm.
Dual Patented Active Components
The formulation incorporates two patented active components, selected and combined to target a broad spectrum of oxygenate impurities. Dispersed at the molecular level across the alumina surface, these components maximize active site utilization. The first targets alcohols, ethers, and ketones through Lewis acid-base interactions, while the second provides enhanced affinity for aldehydes, carboxylic compounds, and peroxides. This dual-component approach ensures comprehensive removal of all common oxygenates in cracked C₂–C₄ streams.
Key Features & Advantages
Deep Removal of Diverse Oxygenates
CD Adsorbent excels at selectively removing a wide range of oxygenate impurities from olefin feedstocks, including alcohols, ethers, aldehydes, carboxylic compounds, ketones, and peroxides. Unlike adsorbents targeting only specific oxygenate species, CD Adsorbent provides comprehensive purification in a single bed, simplifying process design and reducing capital equipment requirements. The chemisorption-based mechanism ensures even trace-level impurities are effectively captured, delivering outlet methanol concentrations of ≤0.5 ppm and water concentrations of ≤1 ppm—achieving ppb-level purification precision that protects sensitive polymerization catalysts.
High Adsorption Capacity and Long Cycles
With a water/methanol adsorption capacity of ≥15% by weight, CD Adsorbent offers exceptional impurity-holding capability that extends adsorption cycles and reduces regeneration frequency. The high specific surface area (380 m²/g) and optimized pore structure (≥0.35 ml/g) work in synergy with dual patented active components to maximize efficiency. This translates to operating cycles of up to 90 days, reducing downtime and operational costs.
Direct Replacement for Imported selexsorb CD
CD Adsorbent is formulated to match the performance characteristics of selexsorb CD, the industry-standard imported adsorbent, making it a direct drop-in replacement for existing installations. Plant operators can switch to CD Adsorbent without modifying equipment, process conditions, or operating procedures, minimizing transition risks and ensuring uninterrupted production. Equivalent performance is validated through extensive laboratory and industrial-scale testing, demonstrating comparable purification efficiency, adsorption capacity, and service life. By choosing CD Adsorbent, operators gain the benefits of domestic supply—shorter lead times, responsive technical support, and cost savings—without sacrificing purification performance.
Long Service Life and Mechanical Durability
Engineered for durability and sustained performance, CD Adsorbent delivers a service life of up to 5 years under typical operating conditions. The high mechanical strength (≥35 N per bead) ensures resistance to attrition and fragmentation during loading, operation, and regeneration cycles, maintaining bed integrity and preventing fine particle formation. The thermally stable alumina carrier and robust active component anchoring withstand repeated regeneration at temperatures up to 300°C without significant performance degradation. This long service life reduces replacement frequency and lowers total cost of ownership.
Low-Temperature Operation and Multi-Contaminant Removal
CD Adsorbent performs effectively across a wide temperature range from 10°C to 120°C, making it suitable for both ambient and low-temperature process applications. Unlike some competing adsorbents requiring elevated temperatures for adequate kinetics, CD Adsorbent maintains high efficiency at lower temperatures, providing process design flexibility and energy savings by eliminating the need for feed preheating.
Beyond primary oxygenate removal, CD Adsorbent provides additional purification benefits including effective water removal (≤1 ppm outlet) and good mercaptan adsorption capability, making it a versatile solution for complex feedstock streams.
Applications
Polyethylene and Polypropylene Production
CD Adsorbent is ideally suited for feedstock purification in polyethylene (PE) and polypropylene (PP) manufacturing plants. Ziegler-Natta and metallocene catalysts are extremely sensitive to oxygenate impurities, which cause catalyst deactivation, reduced molecular weight control, and increased gel formation. By reducing oxygenates to ppb-range concentrations, CD Adsorbent maintains catalyst activity, extends catalyst life, and ensures consistent production of high-quality polyolefin resins. It is compatible with all major polyolefin process technologies including gas-phase, slurry, and solution-phase processes.
C₂–C₄ Hydrocarbon Purification
The adsorbent is designed for purification of cracked C₂ to C₄ hydrocarbon streams—ethylene, propylene, butylene, and mixtures. These streams, from steam cracking or FCC processes, typically contain trace oxygenates formed during cracking or introduced upstream. CD Adsorbent effectively treats these multi-component olefin streams, selectively adsorbing oxygenate impurities without adsorbing valuable olefin products. Its high selectivity ensures minimal loss of desired hydrocarbons while achieving required purification depth.
Broad Petrochemical Applications
Beyond polyolefin production, CD Adsorbent serves various petrochemical processes requiring oxygenate removal: other polymer monomer purification, refinery light ends processing, olefin conversion units, and LPG purification. It also provides added benefit of co-removing water and sulfur compounds, protecting downstream equipment and catalysts while reducing corrosion and helping meet product sulfur specifications.
Technical Specifications
Chemical Composition
- Base material: Aluminum oxide (Al₂O₃) with modifying agents
- Active components: Two patented active components
- Formulation: Proprietary blend for optimal oxygenate adsorption
Physical Properties
- Appearance: White spherical beads
- Bead diameter: 1.5–3.0 mm (Φ1.5–3.0 mm)
- Bulk density: 0.65–0.75 kg/L
- Crush strength: ≥35 N per bead
- Specific surface area: 380 m²/g
- Pore volume: ≥0.35 ml/g
- Loss on ignition (250°C–1200°C): 4.5%
Operating Conditions
- Operating pressure: Atmospheric pressure to 6.0 MPa
- Operating temperature: 10–120°C
- Liquid hourly space velocity (LHSV): 1–5 h⁻¹
- Gas hourly space velocity (GHSV): 500–3,000 h⁻¹
- Bed height to tower diameter ratio: 2–6
- Regeneration temperature: 250–300°C
- Regeneration gas source: Nitrogen (N₂, 99% purity)
- Regeneration gas space velocity: 100–500 h⁻¹
Performance Indicators
- Water/methanol adsorption capacity: ≥15% (by weight)
- Adsorption cycle: Up to 90 days (depending on plant conditions)
- Inlet feed water content: <20 ppm
- Inlet feed methanol content: <10 ppm
- Outlet water content: ≤1 ppm
- Outlet methanol content: ≤0.5 ppm
- Service life: Up to 5 years (depending on plant conditions)
Operating Guidelines
Loading and Startup
Proper loading is essential for optimal performance and uniform flow distribution. Before loading, ensure the adsorption tower is clean, dry, and free of debris or residues. Inspect support grids, screens, and distribution systems for integrity.
Load the adsorbent carefully using a soft method such as a sock or chute to minimize impact and prevent bead fracture. Load uniformly across the bed cross-section to avoid preferential flow channels. After loading, level the bed surface and verify height meets specifications (recommended bed height to tower diameter ratio: 2–6).
Before introducing process feed, condition the bed to remove moisture adsorbed during transportation. Heat gradually using dry nitrogen at a low flow rate with a controlled temperature ramp. After conditioning, cool to operating temperature before introducing feed. Start with a low flow rate and gradually increase, monitoring pressure drop and temperature profiles.
Normal Operation
During normal operation, maintain parameters within specified ranges for optimal performance. Keep feed impurity levels within design specifications (water <20 ppm, methanol <10 ppm), as higher inlet concentrations may reduce cycle length. Regularly monitor outlet impurity levels to track breakthrough and determine optimal regeneration timing. Periodically check pressure drop across the bed; a significant increase may indicate fouling or attrition.
Regeneration
When outlet impurity levels approach specification limits, regenerate to restore adsorption capacity using hot nitrogen (99% purity):
- Drain and purge process fluid with inert gas
- Gradually heat the bed at 100–500 h⁻¹ space velocity to 250–300°C
- Hold at regeneration temperature for sufficient duration for complete desorption
- Gradually cool to operating temperature with clean, dry nitrogen
- Return the adsorber to service
For continuous operation, a dual-bed configuration with one bed in adsorption and one in regeneration is recommended.
Packaging & Storage
Packaging
CD Adsorbent is supplied in standard industrial packaging protecting against moisture and physical damage. Options include 25 kg sealed bags with moisture-barrier liners, 500 kg bulk bags, and steel drums with desiccant packets. All packaging is clearly labeled with product name, specifications, batch number, and date. Custom packaging is available on request.
Storage Recommendations
Store in a dry, covered warehouse at -10°C to 40°C. Keep containers tightly sealed to prevent moisture adsorption. Store away from heat sources, open flame, or corrosive substances. Under proper conditions, shelf life is 24 months from manufacture. Always verify packaging integrity before use and reseal partially opened containers immediately.
Why Choose Us
Trusted Performance
Our CD Adsorbent delivers purification performance equivalent to selexsorb CD, providing the reliability needed for critical polyolefin production. Backed by extensive R&D, rigorous quality control, and industrial validation, our adsorbent consistently achieves ppb-level oxygenate removal that protects valuable catalysts and ensures high-quality output. Every batch is tested against strict quality standards before shipment.
Cost-Effective Domestic Alternative
CD Adsorbent delivers premium imported adsorbent performance with the advantages of domestic manufacturing: shorter lead times, lower logistics costs, and competitive pricing. We maintain adequate inventory for rapid delivery, reducing safety stock requirements. The long service life (up to 5 years) and high adsorption capacity further reduce total cost of ownership.
Expert Technical Support
Our team of adsorption specialists provides comprehensive support from initial evaluation through ongoing operation, including application assessment, process design support, loading supervision, performance optimization, and regeneration troubleshooting. We work closely with customers to deliver tailored purification solutions.
Quality and Supply Reliability
Our manufacturing facilities operate under strict quality management systems, ensuring consistent product quality from raw material selection to final testing. We also understand the importance of uninterrupted supply, with robust manufacturing capabilities, strategic inventory management, and reliable logistics ensuring CD Adsorbent is available when needed. Flexible ordering options help optimize inventory management.
CD Adsorbent: selexsorb CD-equivalent performance with domestic reliability and cost efficiency. Protect your catalysts, ensure product quality, and reduce purification costs.
