Analyze the advantages of the Super Claus process and the EUROCLAUS process

This post was last edited by Shandong Huaxing on 2010-7-30 at 19:59. Both the Super Claus process and the EUROCLAUS process require extensive dilution of the emissions.

This post was last edited by Shandong Huaxing on 2010-7-30 19:59. The SUPERCLAUS® sulfur recovery process is an extension of the traditional Claus process. Based on the conventional CLAUS process, a selective catalytic oxidation section is added to selectively oxidize the residual H2S in the process gas from the final CLAUS stage into elemental sulfur, thereby increasing the sulfur recovery rate to over 99.0 %. Based on this concept, the Claus section of the Super Claus process no longer controls the H2S:SO2=2:1 ratio, but rather controls the H2S concentration at the outlet of the final Claus reactor. Its reaction equation is: H2S + ½ O2 → S + H2O. Since this is a thermodynamically complete reaction, a high sulfur recovery rate can be achieved. Main features of the Super Claus process: 1. It does not require precise control of the H2S/SO2 ratio; instead, it controls the H2S content in the process gas exiting the final Claus reactor to be between 0.6–1.5 vol. %, thereby making the operation more flexible and convenient ； 2. The selective oxidation reaction (H2S + ½ O2 → S + H2O) is a thermodynamically complete reaction, therefore a very high conversion rate can be achieved ； 3. A special selective oxidation catalyst is used, which is insensitive to both water and excess oxygen, and can directly oxidate most of the H2S in Claus off-gases into elemental sulfur. Its efficiency can reach 85%-95%, with no side reactions occurring ； 4. Since the upstream Claus unit operates with an excess of hydrogen sulfide, which reduces the sulfur dioxide content in the exhaust gases, the overall sulfur recovery rate of the plant is high. Therefore, the SUPERCLAUS® reaction section serves both for sulfur recovery and exhaust gas treatment ； 5. Since the Super Claus process operates with excess air, resulting in less sulfur dioxide production, the requirements for air control are not very strict. A simple flow control circuit can be used ； 6. The Super Klaus catalyst possesses good thermal stability, chemical stability, and mechanical strength, resulting in a long catalyst lifespan ； 7. Suitable for a wide range of acidic gas concentrations, with H2S concentrations ranging from 23 vol. % to 93 vol. %. The EUROCLAUS® process was developed on the basis of the SUPERCLAUS® technology. The goal is to increase the sulfur recovery rate to 99.4% or higher without additional investment. The difference between the EUROCLAUS® process and the SUPERCLAUS® process lies in the fact that a layer of hydrogenation catalyst is placed beneath the Claus catalyst in the final stage of the Claus catalytic reactor bed; this catalyst reduces SO2 to S and H2S, thereby **increasing** the overall sulfur recovery rate. Depending on the amount of acidic gas feed and the number of catalytic reactors, the sulfur recovery rate of the EUROCLAUS® process can exceed 99.4 %.

This post was last edited by Shandong Huaxing on 2010-8-4 at 12:50. What’s special about it is the use of a patented catalyst, which is said to be able to convert a high proportion of H2S into S, and to reduce SO2 back to H2S even at low H2 concentrations. In fact, the aforementioned properties have not been confirmed through industrial application, and the operation of the current device is not good. The exhaust gases need to be diluted with a large amount of air in order to meet emission standards. Additionally, since catalysts have strict requirements regarding process conditions, the control system for such installations is of high complexity, the automated control equipment is sophisticated, and operating them is difficult.