Grade 12-18 Si-Al Silica Gel: Specialized Adsorbent for Air Separation & Protective Layer Applications

Engineered for Precision in Critical Industrial Processes

In the high-stakes operations of air separation plants, petrochemical catalysis, and specialized gas drying, the purity and performance of your adsorbents directly impact yield, safety, and operational cost. Aogochem's Grade 12-18 Si-Al Silica Gel is a precision-engineered adsorbent formulated to meet the exacting demands of these critical applications. Its primary and most distinguished role is in the air separation process, where it serves as an essential liquid adsorbent to deeply dry compressed air before cryogenic distillation, preventing ice formation and ensuring the efficiency and safety of oxygen, nitrogen, and argon production. Beyond this, its robust structure and high surface area make it an excellent catalyst carrier in the petrochemical and chemical industries. Uniquely, this grade is also specified as the optimal protective layer for common Si-Al silica gel beds. When deployed as this guard layer—typically constituting about 20% of the total adsorbent volume—it shields the more specialized main adsorbent from contaminants, poisons, and premature aging, thereby extending the entire system's service life and protecting your investment. Aogochem delivers this versatile workhorse with guaranteed consistency, providing the reliable foundation for your most sensitive separation and catalytic processes.

Technical Specifications & Performance Profile

This adsorbent is characterized by a balanced set of properties tailored for durability and effective adsorption in dynamic industrial environments.

Core Physical & Chemical Properties:

• Appearance: High-strength, spherical beads.

• Bulk Density: 650 - 750 g/L

• Crushing Strength: ≥ 80 N (Strength is size-dependent; refer to notes).

• Pore Volume: 0.40 - 0.60 mL/g

• Specific Surface Area: 550 - 650 m²/g

• Moisture Content (as shipped): ≤ 3.0%

• No-Cracking Rate in Water: ≥ 98% (indicating exceptional hydrothermal stability and water resistance).

Adsorption Capacity (at 25°C):
The product demonstrates strong and progressive adsorption performance across a range of humidity conditions, crucial for achieving the required dew point in air drying applications.

Standard Sizes & Packaging:

• Available Mesh Sizes: 1.0-3.0 mm, 2.0-4.0 mm, 2.5-5.0 mm, 3.0-5.0 mm. Custom sizes are available to match specific tower designs.

• Standard Packaging: 25 kg multi-layer bags or 500 kg bulk bags (FIBCs) for industrial-scale delivery.

• Customization: We offer tailored solutions for particle size distribution, packaging, and initial moisture content to optimize performance in your specific system.

Key Applications in Industry

1. Air Separation Unit (ASU) Pre-Purification:
This is the flagship application. Installed in the pre-purification unit (PPU) of cryogenic air separation plants, it removes water vapor and carbon dioxide from compressed air. Deep drying is non-negotiable, as even trace moisture can freeze and block heat exchangers and distillation columns, leading to costly shutdowns. Our gel ensures reliable, deep dehydration for uninterrupted ASU operation.

2. Protective Bed Layer in Adsorption Systems:
A critical, value-adding function. Used upstream of more expensive or specialized adsorbents (like molecular sieves for CO2 removal or other Si-Al gels), this grade acts as a sacrificial guard layer. It absorbs heavier hydrocarbons, trace oils, and other contaminants that could permanently degrade or poison the primary adsorbent, significantly extending the life of the main bed and reducing long-term operating expenses.

3. Catalyst Carrier in Petrochemical & Chemical Processes:
Its high surface area, mechanical strength, and chemical stability make it an ideal inert support (carrier) for active catalytic metals or compounds in various reactions within the refining and chemical manufacturing sectors.

4. General Industrial Gas Drying:
Provides effective dehydration for instrument air, process gases, and breathing air systems where a reliable and robust desiccant is required to prevent corrosion and process upsets.

Competitive Advantages & Selection Rationale

• Proven in Air Separation: Specifically formulated and tested for the demanding pre-purification stage of ASUs, a testament to its deep-drying capability and reliability.

• Superior Hydrothermal Stability: The ≥98% no-cracking rate in water indicates exceptional resistance to physical breakdown upon exposure to moisture, which is vital for maintaining low pressure drop and handling upsets in gas streams.

• Cost-Effective System Protection: Its use as a 20% protective layer is a proven, economical engineering strategy to safeguard more valuable downstream adsorbents, optimizing total lifecycle cost of ownership.

• High Mechanical Integrity: Good crushing strength and low attrition ensure structural longevity over repeated adsorption-regeneration cycles, minimizing operational downtime for bed screening or replacement.

• Flexibility & Support: Aogochem provides not just a product, but application expertise to help determine the optimal grade, size, and bed configuration for your process.

Guidance for Implementation

For air separation pre-purification, the bed is typically designed based on feed air conditions, flow rate, and required regeneration cycle timing. When used as a protective layer, it should be loaded upstream in the same vessel, with the height or volume calculated as approximately 20% of the total adsorbent charge. Regeneration is achieved using heated purge gas in a Temperature Swing Adsorption (TSA) cycle.

Secure the foundation of your critical gas processing systems. Contact Aogochem's engineering support team for technical consultation, adsorption modeling assistance, and to request product samples for qualification testing.