Pre-sulfiding of hydrogenation catalysts

This post was last edited by adsl121 on 2010-8-3 01:33. Using exhaust gas for sulfidation should not pose any problems. The reason might be that the Claus load is too low, resulting in a low sulfur content; or else the hydrogenation catalyst used is not a low-temperature catalyst containing silicon. The hydrogen addition process may not have been carried out as required, as this process needs to be strictly controlled. It is fine to control the vulcanization temperature from rising too high, appropriately increase the concentration of sulfides, and extend the vulcanization time.

This post was last edited by adsl121 on 2010-8-3 01:33. Is the ratio of hydrogen sulfide to sulfur dioxide 4~6/1?

This post was last edited by adsl121 on 2010-8-3 01:33. What are the signs of poor pre-vulcanization performance? Is it due to insufficient temperature rise or some other reason? Please explain, original poster

This post was last edited by adsl121 on 2010-8-3 01:34. We use acidic gas as a raw material for pre-vulcanization, and the results are fairly good

This post was last edited by adsl121 on 2010-8-3 01:34. How do you determine that the pre-vulcanization effect is poor?

This post was last edited by adsl121 on 2010-8-3 01:34. The proper sulfidation of hydrogenation catalysts is crucial for their proper operation and for achieving high hydrogenation conversion rates. Strict requirements are placed on the sulfur compounds present in the hydrogen gas and acidic gases during sulfidation; moreover, overheating is strictly prohibited

This post was last edited by Shandong Huaxing on 2010-8-3 at 12:54. 1. Preparation work ○ The catalyst for the exhaust gas treatment reactor has been installed, and the temperature at the reactor inlet has reached 280–300°C. ○The nitrogen leak test for the pipeline leading to the hydrogen inlet device passed; the blind flange on that pipeline was removed, the valve for the hydrogen inlet was opened, and hydrogen was introduced into the device. ○The reducing gas cut-off valve is opened, and the pressure and flow rate of the reducing gas are controlled by a regulator. 55 ○ An online hydrogen analyzer was installed on the pipeline for the circulation process, and by controlling the hydrogen flow rate, the H2 content in the circulating gas was maintained at 3–5% (V). 2. Catalyst pre-sulfurization: ⑴ Control the inlet temperature of the exhaust gas treatment reactor by adjusting the setting value of the reactor inlet temperature regulator, keeping the temperature of the reactor bed at around 240–250°C. ⑵ Control the hydrogen content in the recycle gas to be approximately 5–6% (V) by adjusting the setting value of the exhaust gas hydrogen content regulator. ⑶Contact the laboratory to analyze the composition of the acidic gas; it is required that the NH3 content in the acidic gas be less than 1% (V), and the content of heavy hydrocarbons be less than 3% (V). ⑷Slowly open the valve for feeding acidic gas into the exhaust gas treatment furnace, and have the H2S content in the gas entering the reactor analyzed; maintain the H2S content in the circulating gas at 0.5–1% (V). ⑸Once hydrogen sulfide gas enters the exhaust gas treatment reactor, the cobalt/molybdenum catalyst begins to undergo pre-sulfidization. The degree of pre-sulfidization of the catalyst is determined by analyzing the H2S content in the gases entering and leaving the reactor; when the H2S concentrations in these gases are similar, it indicates that the pre-sulfidization of the catalyst is complete. ⑹Increase the temperature of the reactor bed used for exhaust gas treatment to 300°C and maintain this temperature for 4 hours; thereafter, reduce the inlet temperature of the reactor to 280°C and close tightly the valve through which acidic gases enter the exhaust gas treatment furnace. Catalyst presulfurization is complete. ⑺The acidic pipeline should be purged with nitrogen once, and then the valves at both ends of the pipeline should be closed tightly.