Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutd...
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutd...
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutd...
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutd...
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutd...
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutd...
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutd...
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutd...
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PRE-SULFIDING & ON-LINE SULFIDING of VULCAN Series CoMo and NiMo Catalyst in Synthesis Gas Applications

PRE-SULFIDING & ON-LINE SULFIDING of VULCAN Series CoMo and NiMo Catalyst in Synthesis Gas Applications
Published on: Mar 4, 2016
Published in: Technology      Business      
Source: www.slideshare.net


Transcripts - PRE-SULFIDING & ON-LINE SULFIDING of VULCAN Series CoMo and NiMo Catalyst in Synthesis Gas Applications

  • 1. 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 GBH Enterprises, Ltd. PRE-SULFIDING & ON-LINE SULFIDING of VULCAN Series CoMo and NiMo Catalyst in Synthesis Gas Applications 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.
  • 2. 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 PRE-SULFIDING & ON-LINE SULFIDING PROCEDURES IN SYNGAS APPLICATIONS VULCAN Series VHT-S101/S103 GENERAL The purpose of the CoMo or NiMo HDS catalyst is to convert organic sulfur compounds such as mercaptans, sulfides and thiophenes to H2S, which can then be absorbed by zinc oxide. The organic sulfur compounds are converted to H2S by reaction with hydrogen in the feed. Simple compounds also crack thermally at temperatures in the range 150-400°C forming H2S and (in the absence of hydrogen) olefins. The catalysts do not normally require being sulfided before operation. They have sufficient initial activity and become adequately sulfided by reaction with the sulfur compounds in the process stream during normal operation. Pre-sulfiding and on-line sulfiding should be considered in three situations, a) The initial feed contains < 2 ppmv total sulfur, especially where there is a high hydrogen content (e.g.: refinery off gas feed) and S << 1 ppmv. b) If the HDS catalyst is required to operate downstream of a zinc oxide bed, such as in a system with 2 vessels each containing HDS and zinc oxide catalysts. In this case, the second HDS catalyst would operate for a long period in a sulfur free gas. c) The initial feed is a high sulfur naphtha where there is > 20 ppmw S as thiophenic sulfur compounds. During normal operation in cases (a) and (b) it is advised to provide continuous or periodic sulfur dosing. This document deals with the pre-sulfiding and on-line sulfiding procedures in turn;
  • 3. 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 PRE-SULFIDING PROCEDURE Pre-sulfiding should achieve a sulfur loading of 1 -2 wt% on the catalyst. It is carried out on fresh catalyst delivered to site in the oxide form. • To bring the VULCAN VHT-S101/S103 catalyst to the sulfided and active state, a quantity of at least 1 wt% of sulfur per weight of catalyst has to be brought on to the catalyst before feed is introduced into the front-end of the hydrodesulfurization (HDS) reactor. • Dimethyl Disulfide (DMDS) contains approximately 1kg of sulfur per 1.5 liters of liquid • DMDS will be injected into a nitrogen flow via small pump and the resulting gas mixture will be injected into the Hydrodesulfurization (HDS) reactor at the top of this reactor. • DMDS injection will be continued till a sufficient quantity of DMDS has been injected (See above). • DMDS injection can be started when the inlet, outlet and bed temperatures of the HDS reactor bed are all indicating at least 230°C. Procedure: 1. The HDS reactor bed is heated up to a temperature of 230°C with nitrogen circulation, with steam flowing through the reformer. The gas space velocity used should be as close to full feed rate as possible, to ensure good gas distribution. There will be a minimum flowrate which needs to be used to ensure that adequate gas distribution is attained, for an adiabatic catalyst bed this is typically around 300 hr -1 . 2. Make sure that the HDS reactor bed is heated up equally by checking its inlet, outlet and bed temperatures. 3. In situ pre-sulfiding will be achieved by a nitrogen atmosphere and dosing of DMDS. 4. As soon as the temperatures, as indicated under point 2, are at least 230°C and are stable, the in situ pre-sulfiding atmosphere can be initiated.
  • 4. 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. The nitrogen flow fed through the front end of the unit can be vented to flare. 6. Make sure that after the introduction of nitrogen to the HDS reactor the temperatures, as indicated under step 2, are still at least 230°C and are stable before the DMDS dosing is allowed to start. 7. DMDS dosing can be started with a rate of 10 l/hr. For HDS catalyst in situ pre-sulfiding it is usual to use around 1% (v/v) of the sulfur compound. When DMDS injection is started, the actual DMDS injection flow should be noted. 8. As soon as DMDS dosing has initiated the HDS reactor outlet gas should be monitored continuously (every 5 minutes for the first half hour) for the presence of total sulfur (for instance with Dragger tubes), to check if in situ pre-sulfiding has commenced or not. In situ pre-sulfiding has commenced when the HDS reactor outlet gas, directly downstream of the HDS catalyst and upstream of the ZnO H2S removal absorbent, shows no sulfur present. 9. If the HDS reactor outlet gas shows the presence of (total) sulfur in bulk, in situ pre-sulfiding has not commenced, and the dosing of DMDS should be immediately stopped. 10. When DMDS dosing has been stopped warm up the HDS reactor further by 20°C to a temperature of 250°C. 11. As soon as the temperatures as indicated under point 2 are at least 250°C and are stable, DMDS dosing at a dosing rate of 10 l/hr is allowed to start again in the exact order as indicated above. 12. Repeat steps 9, 10 and 11. Every time the in situ pre-sulfiding has not commenced raise the temperatures as indicated under step 2 by 20°C before trying again. A maximum temperature limit of 300 C is advisable until the in situ pre- sulfiding procedure is complete.
  • 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 13. After the first half hour of continuous measurement (as above) if the HDS reactor outlet gas does not show a total sulfur presence, monitoring can be reduced to every half hour, with the DMDS concentration in the nitrogen being kept constant throughout. During the in situ pre-sulfiding procedure there should be no total sulfur in the exit from the HDS catalyst and upstream of the ZnO (VULCAN VSG- S201) absorbent. 14. DMDS injection should be continued until the required amount of DMDS required has been injected (See above). As soon as at least this amount of DMDS has been injected DMDS injection can be stopped. 15. The HDS reactor will be warmed up further to temperatures ready for introducing hydrocarbon feed into the unit. The feed as should be introduced as per normal recommended start up/ operating procedures.
  • 6. 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 ON-LINE SULFIDING PROCEDURE In order to maintain the catalyst in a sulfided state 2-3 ppmv S is required under typical conditions. Should this level not be present on-line dosing is recommended. This can either be via continuous injection of a sulfur source (such as DMDS) at a level of 2-3 ppmv, or should be conducted every 8 - 10 weeks to deliver preferably 1 wt% S onto the HDS catalysts. This figure may be less due to existing sulfur already on the catalyst from normal operation. 1. Ensure that the HDS reactor temperatures are at least 230°C and are stable before the DMDS dosing is allowed to start. 2. DMDS dosing can be started with a rate of 10 l/hr. For HDS catalyst periodic on-line sulfiding it is usual to use around 1% (v/v) of the sulfur compound. Should the dosing be continuous a lower level may be required. When DMDS injection is started, the actual DMDS injection flow should be noted. 3. As soon as DMDS dosing has initiated the HDS reactor outlet gas should be monitored continuously (every 5 minutes for the first half hour) for the presence of total sulfur (for instance with Dragger tubes), to check if on- line sulfiding has commenced or not. On-line sulfiding has commenced when the HDS reactor outlet gas, directly downstream of the HDS catalyst and upstream of the ZnO H2S removal absorbent, shows no sulfur present. 4. Should the outlet sulfur be equal to inlet sulfur, and the reactor is at normal operating temperature, the catalyst is in the sulfided state. In this case the dosing period (nominally 8-10 weeks) should be reviewed. 5. If the HDS reactor outlet gas shows the presence of (total) sulfur in bulk, and the reactor is not at normal operating temperature, on-line sulfiding has not commenced, and the dosing of DMDS should be immediately stopped. 6. If DMDS dosing has to be stopped warm up the HDS reactor further to normal operating temperature.
  • 7. 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 7. As soon as the temperature has reached the normal operating level and is stable, DMDS dosing at a dosing rate of 10 l/hr is allowed to start again. 8. After the first half hour of continuous measurement (as above) if the HDS reactor outlet gas does not show a total sulfur presence, monitoring can be reduced to every half hour, with the DMDS concentration in the nitrogen being kept constant throughout. During the on-line sulfiding procedure there should be no total sulfur in the exit from the HDS catalyst and upstream of the ZnO absorbent. 9. DMDS injection should be continued until the required amount of DMDS required has been injected (See above). As soon as this amount of DMDS has been injected DMDS injection can be stopped. 10. The normal feedstock should be re-introduced as per normal recommended start up/ operating procedures. Note: VULCAN Series Hydrogenation Catalyst in Hydrodesulfurization (HDS) VHT-S101 Co, Mo, γ-Al2O3 VHT-S103 Ni, Co, Mo, γ-Al2O3 Other VULCAN Series HDS catalyst VHT-S102 Fe, Mo, γ-Al2O3 VHT-N103 Ni, WO3, Mo, γ-Al2O3
  • 8. 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

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