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Sulfur Recovery 

Envitrack has extensive experience in supplying sulfur recovery catalysts (for Claus Process and Tail Gas Treatment) and offers reliable solutions for various industrial applications. In addition, we can also provide troubleshooting and consulting services to optimize system performance and improve recovery efficiency.

Claus Process with Direct Oxidation Reactor

The Claus Process is the leading gas desulfurization method, recovering elemental sulfur from acid gases, widely used in refineries and steel plants.

 

The addition of a direct oxidation reactor further enhances sulfur recovery, achieving yields above 99%. Envitrack has developed a next-generation direct oxidation catalyst, RCAT®-9007, offering an alternative to older types of catalysts used in the industry.

Envitrack Process Claus

The Sulfur Recovery Unit (SRU) operates using a modified Claus Process, incorporating two or three Claus Reactors and one Direct Oxidation Reactor to maximize sulfur recovery. In the burner, Hâ‚‚S is partially combusted at a high temperature, producing sulfur dioxide (SOâ‚‚). Within Claus Reactors, Hâ‚‚S and SOâ‚‚ react over a Claus catalyst to form elemental sulfur (Sâ‚“). After each catalytic stage, liquid sulfur is collected in Claus Condensers, while unreacted gases advance to the next stage.

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The Direct Oxidation Reactor further boosts sulfur recovery by selectively oxidizing residual Hâ‚‚S into elemental sulfur, utilizing the advanced RCAT®-9007 catalyst for superior conversion and selectivity to sulfur.​​

Sulphur Recovery Catalysts

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  • Direct Oxidation Catalyst RCAT®-9007

  • Alumina Based Catalyst RCAT®-9001

  • TiOâ‚‚ Promoted catalyst RCAT®-9002

  • TiOâ‚‚ based RCAT®-9003 for COS and CSâ‚‚ hydrolysis

  • Fe-promoted catalyst RCAT®-9004

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RCAT-9001 Envitrack Claus

Tail Gas Treatment

The tail gas treatment process is an essential step in improving sulfur recovery efficiency. It reduces sulfur vapor and SOâ‚‚ contained in the tail gas from the Claus process by converting it back to Hâ‚‚S in a designated reactor using special cobalt-molybdenum (CoMo) based catalysts. This catalytic step ensures further improvement of the overall sulfur recovery in the SRU. First, tail gas goes through a reduction section, where sulfur compounds are converted to Hâ‚‚S, followed by an absorption section, where the Hâ‚‚S is absorbed into an amine solution. The captured Hâ‚‚S is then returned to the Claus process for further conversion to sulfur.

Envitrack Process Claus TGT

This additional step, when combined with the Claus process, ensures minimal sulfur emissions and highly efficient sulfur recovery.

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In typical oil refining plants and gas processing plants, Claus process followed by the tail gas treatment process can yield sulfur recovery rate of over 99.9%, depending on the composition of the feed gas.

Tail Gas Treatment

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CoMo based Tail Gas Treatment catalysts:

  • RCAT®-4210T

  • RCAT®-4210S​

Low-temperature Tail Gas Treatment catalysts:

  • RCAT®-4211T

  • RCAT®-4211S

RCAT-4210S Envitrack TGT

Inert Support Spheres

Inert materials are excellent at preventing catalyst poisoning, clogging of catalyst pores, and prolonging their operational lifetime. Sulfur Recovery Units catalysts are traditionally supported by high resistence ceramic balls of various sizes.

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CBSM 19 (High Resistance Ceramic Balls) are made only with high-quality materials and precisely controlled processes.​

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The high-quality CBSM support media ensures optimal performance with your catalyst, eliminating common issues found with lower-quality alternatives. In many cases, it has been proven to extend catalyst life and prevent premature replacement. CBSM is ideal for applications such as sulfur recovery, alkylation, dehydrogenation, desulfurization, catalytic conversion, catalytic cracking, catalytic oxidation, catalytic reforming, hydrofining, isomerization, powerforming, and thermal cracking.

Envitrack supplies also high purity alumina balls ABSM suitable for high temperature processes.

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Envitrack s.r.o. 

Thákurova 531/4, 160 00 Prague 6, Czech Republic

+420 724 393 596 info@envitrack.com

© 2025 Envitrack s.r.o. All Rights Reserved.

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