Low Temperature Shift Catalyst Reduction Procedure
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The document outlines the reduction procedure for the Vulcan VSG-C111/C112 low temperature shift catalyst, emphasizing the importance of controlled conditions to avoid thermal damage during the process. It details the steps required for safely activating the catalyst, including temperature management and gas flow specifications, and provides contingencies for potential issues like excessive temperature rises. The document also highlights key equipment requirements and safety considerations for successful catalyst performance in refining and petrochemical industries.
Low Temperature Shift Catalyst Reduction Procedure
- 1. GBH Enterprises, Ltd. VULCAN VSG-C111/ C112 Low Temperature Shift Catalyst Reduction Procedure Process Information Disclaimer Information contained in this publication or as otherwise supplied to Users is believed to be accurate and correct at time of going to press, and is given in good faith, but it is for the User to satisfy itself of the suitability of the Product for its own particular purpose. GBHE gives no warranty as to the fitness of the Product for any particular purpose and any implied warranty or condition (statutory or otherwise) is excluded except to the extent that exclusion is prevented by law. GBHE accepts no liability for loss, damage or personnel injury caused or resulting from reliance on this information. Freedom under Patent, Copyright and Designs cannot be assumed. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries Web Site: www.GBHEnterprises.com
- 2. VULCAN Series VSG-C111 / C112 “Low Temperature Shift Catalyst” REDUCTION PROCEDURE VSG-C111 as supplied contains copper oxide; it is activated for the low temperature shift duty by reducing the copper oxide component to metallic copper with hydrogen. The reaction is highly exothermic. In order to achieve maximum activity, good performance and long life, it is essential that the reduction is conducted under correctly controlled conditions. Great care must be taken to avoid thermal damage during this critical operation. RECOMMENDED PROCEDURE 1. Purge the converter free of oxygen with an inert gas. If natural gas is to be used as the carrier gas, then normal safety procedures for gas/air systems should be followed. 2. Check all associated pipework is free of water, and then establish a flow of carrier gas (nitrogen or natural gas) at a space velocity of 200-800 hrs-1. The reduction is more quickly completed at higher space velocities. 3. On most plants the reduction may be carried out at any convenient pressure. To ensure adequate flow distribution, it is recommended that the pressure be such that the superficial linear velocity is at least 0.2 ft/sec. 4. Heat the catalyst at a rate of not greater than 150oF/hour. During the heat up, while the bed temperatures are below 250oF, the hydrogen injection valve should be checked and calculated over the range 0.5% - 2% hydrogen inlet the converter. This should be done as swiftly as possible and the valve isolated between injections. 5. When at least one-third of the bed is at 330-350oF establish a hydrogen flow, aiming for not greater than 1% H2 at this stage. When gas analysis confirms the hydrogen concentration and the exotherm is stable, the hydrogen concentration may be raised to approximately 2% in stages. THIS MUST BE DONE WITH CAUTION AND ONLY IF THE CATALYST TEMPERATURES ARE AT A SAFE LEVEL AND THE ENTIRE SYSTEM IS STABLE. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries Web Site: www.GBHEnterprises.com
- 3. With VSG-C111 the maximum bed temperature during reduction should be limited to 450-455oF. In any situation, if a bed temperature reaches 480oF then the inlet hydrogen should be reduced to less than 1%. 6. When an elevated hydrogen concentration consistent with a safe temperature is established, the reduction should be allowed to continue until the exit gas analysis indicates a rising hydrogen concentration. When the inlet and exit hydrogen concentrations differ by less than 0.5%, the inlet hydrogen should be raised above 5% in stages. The bed temperatures should be watched closely after each hydrogen adjustment. 7. The entire bed should be raised to 400-420oF. 8. The reduction can be considered complete when the entire bed is at 400oF or greater and the inlet and exit hydrogen concentrations differ by no more than 0.2%. 9. The catalyst can now be put into service. POINTS TO NOTE A) EQUIPMENT/UTILITIES I) Carrier Gas Desulfurized natural gas and nitrogen are acceptable. Ideally the carrier gas is free of hydrogen and oxygen. In the event of contamination, levels should be: Hydrogen not greater than 0.5% Oxygen not greater than 0.1% (Note: 0.01% oxygen consumes 0.2% hydrogen and produces an exotherm of 30oF in nitrogen.) II) Hydrogen Source The hydrogen should be free of sulfur and chlorides. Carbon monoxide in the hydrogen is acceptable but the additional associated temperature rise must be allowed for. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries Web Site: www.GBHEnterprises.com
- 4. III) Temperature Control There must be an adequate mechanism for inlet gas temperature control and as an absolute minimum thermocouples at the inlet and exit of the catalyst bed. Preferably, for use not only during the reduction but for performance monitoring throughout the life of the catalyst, thermocouples should be spaced throughout the catalyst bed. IV) Sample Points Gas samples points must be available inlet and exit the bed. V) Pressure Control The system must have an adequate mechanism for pressure control. Wild pressure fluctuations might otherwise result in unacceptable surges of hydrogen flow to the catalyst. VI) Cooling/Condensing/Catchpot Recirculating systems must have a mechanism for controlled removal of the water reduction. B) CONTINGENCIES I) with natural gas as the carrier in the event of an excessively high temperature (above 550oF), additional hydrogen can be produced by the thermal cracking of the gas. Should, for whatever reason, an excessive temperature rise occurs, the natural gas must be isolated and the contents of the reactor purged and cooled with nitrogen. II) In the event of a temperature runaway, the vessel pressure should be reduced to minimize any chance of vessel damage. III) Again, in the event of thermal runaway, if possible the heat should be vented by reverse flow to avoid damage to hitherto unaffected catalyst. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries Web Site: www.GBHEnterprises.com
- 5. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts / Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries Web Site: www.GBHEnterprises.com