Dry gas, hydrogen production from natural gas, catalyst poisoning due to conversion

Regeneration after sulfur poisoning: In the case of mild sulfur poisoning, it is possible to restore the catalyst’s activity by using clean feedstock and operating under high water-to-carbon ratios. Alternatively, the feedstock can be changed to conditions suitable for reduction, allowing the catalyst to gradually release sulfur and thus regain its activity. When the poisoning is severe, redox methods can be employed to regenerate it. The specific steps are as follows: (1) Oxidize the catalyst with steam at near-atmospheric pressure, keeping the bed temperature 10%–20% lower than that during normal operation, for a duration of about 6–8 hours. (2) Hydrogen is added to the steam, gradually reducing the H2O/H2 ratio from 20 to around 3, and this condition is maintained for 2–4 hours to carry out catalyst reduction. (3) Re-oxidize with steam for 4–6 hours using the method described in (1) above. (4) Follow the method described in (2) above, then establish normal reduction conditions, and subsequently restore normal operating conditions. During the regeneration process, the H2S content at the converter outlet should be analyzed regularly to assess the desulfurization efficiency. When catalyst poisoning is severe, it causes carbon deposition on the catalyst; therefore, the \"carbon burning\" method must be used to remove both the carbon deposit and sulfur simultaneously, thereby regenerating the catalyst. The method is: remove the raw material, carbonize it using steam, with the amount of steam being 30–40% of that used in normal operations, and the pressure at around 1.0 MPa. The temperature is strictly controlled to not exceed that during operation; carbon burning ends once the outlet CO2 level drops and stabilizes at a lower value. If necessary, a small amount of air can be added to the water vapor, but the oxygen content must be strictly controlled to prevent overheating. After carbon burning is complete, restore the catalyst as required to resume operation. Chlorine poisoning: Chlorine can also poison nickel catalysts, with an effect similar to that of sulfur. The poisoning of the conversion catalyst by chlorine and chlorides is reversible; the conversion rate can be restored after regeneration. However, if an excessive amount of chlorine is introduced, the catalyst can become permanently inactive due to sintering (the formation of low-melting-point surface compounds).

The signs of sulfur poisoning of the conversion catalyst are: an increase in methane content at the outlet of the furnace tubes, an increase in the temperature at the outlet of the conversion furnace, an increase in the wall temperature of the conversion furnace tubes, a decrease in fuel consumption, and an increase in system resistance.

Specializing in the recycling of waste catalysts, including various non-ferrous metal wastes such as copper, zinc, nickel, molybdenum, platinum, and palladium. We possess a license for handling hazardous waste and have all the necessary environmental compliance certifications. Manufacturers and individuals who are in need can contact Manager Cha at phone number: 13203847799

Specializing in the recycling of waste catalysts, including various non-ferrous metal wastes such as copper, zinc, nickel, molybdenum, platinum, and palladium. We possess a license for handling hazardous waste and have all the necessary environmental compliance certifications. Manufacturers and individuals who are in need can contact Manager Cha at phone number: 13203847799