Desulfurization and arsenic removal catalyst

Desulfurization & De-arsenification Catalyst

Dual-Function Purification Solution for Hydrocarbon Processing

Our Desulfurization & De-arsenification Catalyst is a high-performance purification solution engineered to remove arsenic compounds and phosphine from liquid and gaseous hydrocarbon feedstocks at normal and medium temperatures, while simultaneously delivering deep desulfurization. Designed with a large-pore, high-specific-surface-area activated alumina support loaded with carefully selected active components, this catalyst offers exceptional removal efficiency, large arsenic capacity, and reliable long-term performance. It is particularly effective for propylene purification and polyolefin production processes, where even trace levels of contaminants can cause irreversible damage to downstream catalysts and substantial economic losses.

Core Advantages

Dual Desulfurization & De-arsenification Capability

Unlike single-function purification materials, our catalyst removes both arsenic compounds and sulfur contaminants in a single fixed-bed unit, reducing capital equipment costs and simplifying process flow design.

High Arsenic Removal Efficiency

Achieves deep removal of arsenic hydride and alkyl arsenic compounds, ensuring outlet arsenic levels meet the strictest requirements for polymerization-grade feedstocks.

Large Arsenic Capacity

The optimized pore structure and highly dispersed active phase provide substantial arsenic holding capacity, extending service life and reducing change-out frequency.

Outstanding Mechanical Strength

Manufactured with robust forming technology, the catalyst exhibits excellent crush strength and attrition resistance, maintaining physical integrity throughout operation.

Broad Feedstock Adaptability

Effective across a wide range of hydrocarbon streams, from propylene to liquid hydrocarbons including naphtha, gasoline, diesel, kerosene, and ethylene cracker feedstocks.

Stable Performance

Delivers consistent purification results across normal to medium temperature ranges, accommodating process fluctuations without compromising removal efficiency.

How It Works

De-arsenification & Phosphine Removal

The catalyst uses active metal components supported on high-surface-area activated alumina. When arsenic-containing feedstock passes through the bed, arsenic compounds such as arsine (AsH₃) and organic arsenic species react with active metal oxide sites, forming stable metal arsenide compounds and elemental arsenic that deposit within the pore structure. Phosphine (PH₃) follows a similar mechanism, forming stable metal phosphides.

The large-pore design is critical here—it facilitates deep diffusion of contaminants into the catalyst interior, maximizing utilization of the active phase rather than limiting reaction to the external surface. This is particularly important for liquid-phase applications where molecular diffusion is slower than in gas phase. Without adequate pore size, arsenic would only react at the particle surface, causing premature breakthrough and wasting most of the active material.

Desulfurization Mechanism

In parallel, the active components catalyze sulfur compound removal. Hydrogen sulfide (H₂S), carbonyl sulfide (COS), mercaptans, and other reactive sulfur species react with the metal oxide active phase to form stable metal sulfides. The high specific surface area of the activated alumina support ensures excellent dispersion of active sites, promoting efficient sulfur capture.

This simultaneous removal of arsenic, phosphine, and sulfur protects downstream catalysts from multiple poisoning pathways, ensuring longer catalyst life and more consistent process performance.

The Critical Role of Activated Alumina Carrier Design

Why Large-Pore, High-Surface-Area Support Matters

The catalyst support is fundamental to purification performance. Our activated alumina is specifically engineered with large pore diameters and high specific surface area, directly impacting real-world performance:

Enhanced Mass Transfer: Large pores reduce diffusion resistance, allowing arsenic and sulfur compounds to penetrate deeper into catalyst particles rather than reacting only at the external surface. This is especially critical for liquid-phase applications where molecular diffusion coefficients are orders of magnitude lower than in gas phase. Without adequate pore size, internal active sites remain inaccessible, effectively wasting significant active material.

Higher Active Site Density: High specific surface area provides more anchoring points for active metal components, enabling higher loading while maintaining excellent dispersion. This means more reactive sites per unit volume of catalyst, directly improving both removal efficiency and total contaminant capacity.

Improved Utilization Efficiency: The combination of large pores and high surface area ensures the active phase is distributed throughout the entire catalyst particle, not just on the surface. This maximizes utilization of expensive active metals and extends catalyst service life by delaying breakthrough.

Thermal & Mechanical Stability: Activated alumina provides excellent structural stability under varying process conditions, maintaining pore structure and surface area throughout service life. This stability ensures consistent performance rather than rapid deactivation from sintering or structural collapse.

Contaminant Poisoning: Why Deep Purification Is Essential

Arsenic, phosphine, and sulfur compounds are among the most severe poisons for industrial catalysts, and their impact on downstream processes cannot be overstated.

Arsenic Poisoning of Polyolefin Catalysts

In polyolefin production, Ziegler-Natta and metallocene catalysts are extraordinarily sensitive to arsenic contamination. Arsenic compounds bind irreversibly to active metal centers, causing permanent deactivation that cannot be reversed by regeneration. Even ppb-level arsenic in propylene feed can:

• Reduce catalyst activity significantly, requiring higher catalyst feed rates
• Diminish polymer quality by altering molecular weight distribution and morphology
• Increase costs through higher catalyst consumption and more frequent reactor cleaning
• Cause unplanned shutdowns if poisoning progresses rapidly

The economic impact is substantial—replacing a batch of polyolefin catalyst can cost millions, and lost production during shutdown adds further financial burden. A reliable de-arsenification guard bed is therefore not just a processing step but an essential investment protection measure.

Cumulative Poisoning Effect

Phosphine follows a similar pathway, forming strong bonds with transition metal active sites and rendering them inactive. Sulfur compounds, while sometimes partially reversible, also reduce catalyst activity and can alter selectivity. The combination of all three contaminant types—arsenic, phosphorus, and sulfur—creates a cumulative poisoning effect that accelerates deactivation far more rapidly than any single contaminant alone.

Our dual-function catalyst addresses all three contaminant classes in a single bed, providing comprehensive protection that single-purpose purification materials cannot match.

Key Performance Features

High Arsenide Removal Rate

• Achieves ultra-deep arsenic removal from hydrocarbon feedstocks to ppb levels
• Effective for both inorganic arsenic (AsH₃) and organic arsenic compounds
• Also removes phosphine (PH₃) and sulfur compounds for comprehensive protection

Stable Performance

• Consistent removal efficiency throughout the catalyst service life
• Resistant to process upsets and feed composition variations
• Predictable breakthrough curves for reliable production planning

Strong Temperature Adaptability

• Normal temperature operation: Ideal for liquid hydrocarbon applications including naphtha, gasoline, diesel, kerosene, and ethylene cracker feedstocks where energy-intensive heating is undesirable. Ambient temperature operation reduces utility costs and simplifies integration into existing processes.
• Medium temperature operation: For gas-phase applications such as propylene purification where slightly elevated temperatures enhance reaction kinetics and improve mass transfer. Medium-temperature operation can also achieve deeper removal when feed contaminant concentrations are higher.
• The catalyst's ability to perform across this range provides operators with flexibility to adjust conditions based on feed characteristics.

Excellent Mechanical Strength

• Reduced loading breakage: High crush strength minimizes particle attrition during transport and reactor loading, maintaining designed particle size distribution.
• Stable pressure drop: Structurally intact particles prevent bed compaction and channeling, ensuring uniform flow distribution and consistent pressure drop throughout service life.
• Less fine generation: Lower attrition means fewer fine particles that could carry over to downstream equipment, reducing fouling and maintenance.
• Longer effective life: Mechanically robust catalyst maintains activity longer because active surface area is not lost through particle disintegration.

Large Arsenic Capacity

• High arsenic saturation capacity extends catalyst service intervals
• Optimized pore structure enables deep arsenic penetration into particles
• Efficient utilization of active components reduces replacement frequency
• Lower total cost of ownership through extended bed life

Application Areas

Propylene Purification

Particularly specialized for propylene feedstock purification, protecting sensitive polymerization catalysts from arsenic and sulfur poisoning. Our de-arsenification catalyst ensures propylene purity meets the strictest polymerization-grade standards.

Liquid Hydrocarbon Refining

Operates at ambient temperatures for removing arsenic compounds and phosphine from liquid hydrocarbon streams including naphtha, gasoline, diesel, and kerosene. Suitable for refinery pretreatment processes where energy-efficient, low-temperature operation is preferred.

Ethylene Cracker Feed Pretreatment

Purifies cracker feedstocks to protect downstream separation and purification units. Arsenic and sulfur contamination can foul heat exchangers, poison hydrogenation catalysts, and reduce product purity.

Polyolefin Plant Protection

Serves as a critical guard bed for polymerization reactors. By removing arsenic, phosphine, and sulfur from olefin feeds, it prevents catalyst poisoning and ensures consistent polymer product quality.

General Petrochemical Feed Purification

Suitable for any hydrocarbon processing operation where arsenic and sulfur contamination threatens catalyst performance or product quality.

Technical Specifications Overview

表格PropertyDescriptionCarrierLarge-pore, high-specific-surface-area activated aluminaActive ComponentsHigh-performance active metal phase via impregnation processPrimary FunctionsDe-arsenification, phosphine removal, deep desulfurizationTarget ContaminantsArsenic compounds, phosphine, sulfur compounds (H₂S, COS, mercaptans)Applicable FeedstocksPropylene, naphtha, gasoline, diesel, kerosene, ethylene cracker feedstocksOperating TemperatureNormal to medium temperature rangeKey AdvantagesHigh removal rate, large arsenic capacity, stable performance, strong adaptability, excellent mechanical strength

Note: Detailed technical specifications are available upon request.

Success Story: Shandong Chambroad Petrochemical Polyolefin Unit

Our Desulfurization & De-arsenification Catalyst has been successfully applied at Shandong Chambroad Petrochemical's polyolefin production facility, demonstrating outstanding real-world performance.

Project Background

Shandong Chambroad Petrochemical required a reliable purification solution for its polyolefin unit to protect valuable polymerization catalysts from arsenic and sulfur contamination. The plant needed consistent deep purification performance while minimizing operational costs and maintenance requirements.

Solution Implementation

Our dual-function catalyst was installed as a guard bed in the polyolefin unit's feed purification system. It was selected for its proven ability to achieve deep arsenic removal while simultaneously handling sulfur contaminants and phosphine, providing comprehensive protection for the downstream polymerization process.

Operational Results

Since commissioning, the catalyst has delivered excellent performance:

• Consistent removal of arsenic and sulfur contaminants to required specification levels
• Stable pressure drop across the catalyst bed, confirming good mechanical integrity
• Reliable operation with no unexpected breakthrough events
• Effective protection of downstream polymerization catalysts
• Extended service life compared to previous purification materials

The successful application at Shandong Chambroad Petrochemical validates our catalyst's performance in real industrial conditions and demonstrates its value for polyolefin production facilities.

Why Choose Our Catalyst?

Our Desulfurization & De-arsenification Catalyst combines advanced material science with practical industrial engineering to deliver reliable purification performance under real-world conditions. The large-pore activated alumina support, optimized active phase formulation, and precision manufacturing result in:

• Proven industrial performance verified in commercial-scale polyolefin operations
• Dual functionality that reduces equipment complexity and capital costs
• Long service life through high arsenic capacity and efficient active site utilization
• Robust mechanical properties that minimize operational issues
• Versatile application across diverse hydrocarbon streams and operating conditions

Whether you're operating a polypropylene plant, refinery, or ethylene production facility, our catalyst provides the purification performance you need to protect your catalyst investment, maintain product quality, and optimize production economics.

Contact our technical sales team to discuss your specific purification requirements and receive a customized solution recommendation.