What issues should be considered when sulfiding sulfur-resistant shift catalysts for water-coal slurry gasification?

What’s the use of vulcanization anymore? Pre-vulcanization is what’s popular these days: lol

During vulcanization, it is sufficient to control the amount of vulcanizing agent used, the vulcanization speed, and the volume of gas. There are not many things to pay attention to during vulcanization. If carbon disulfide is used, care must be taken to keep the storage tank for carbon disulfide cooled and to monitor it continuously. The most important thing is to maintain good relations with the environmental protection authorities during vulcanization.

Gasification of water-coal slurry is relatively easy to carry out; the carbon monoxide content is not high, and the water-to-gas ratio is quite high, allowing for a large volume of gas to pass through – it’s a robust, practical approach!

Could you explain in detail the gas introduction process in water gas sulfurization?

It’s impossible to describe in detail; it mainly depends on experience.

Our company uses CS2 hydrogen sulfidation 1. Before carrying out catalytic sulfidation, it is ensured that all on-site maintenance tasks are completed, the catalyst has been installed, the system’s airtightness test has passed, and the purging process has been successful. Utility systems: water, gas, steam, etc. are all in normal operation. The nitrogen circulation fan meets the startup conditions. The hydrogen gas required for vulcanization has arrived at the site and is ready for use; the system for replenishing hydrogen gas has also been installed. The carbon disulfide tank has been filled with CS2 and pressurized with nitrogen to an appropriate pressure for normal use. The startup heater is in normal standby mode. The instruments and valves have all been calibrated. A sufficient hydrogen source should be ensured during catalyst sulfidation. 2. During the heating and vulcanization processes, careful recording must be maintained (once per hour); the heating curve, operation records, and analysis data should be properly preserved. 3. During sulfidation, the temperature at hot spots must be strictly controlled to be below the catalyst’s heat resistance limit. 4. If overheating occurs, the bed temperature can be cooled to around 250°C by reducing or stopping the supply of carbon disulfide and increasing the amount of nitrogen, after which carbon disulfide can be gradually added back to continue the sulfidation process. 5. During the heating and vulcanization phase, the inlet and outlet of the converter are analyzed once per hour. 6. During the deep sulfidation of the catalyst, close attention should be paid to the bed temperature as the system temperature is increased. If the bed temperature rises rapidly, heating should be temporarily stopped; heating can resume once the temperature stabilizes. 7. Each separator should drain water promptly to prevent water from entering the circulating nitrogen blower and the catalyst bed, which could damage the equipment and affect the strength and activity of the catalyst. 8. During sulfidation, the hydrogen content should be maintained at around 10–20% (on a dry basis) to ensure complete reaction of carbon disulfide. 9. The amount of carbon disulfide added at one time should not be excessive; it is necessary to add it in small amounts multiple times to prevent overheating. I hope this is helpful to you

8. With less hydrogen available, the reaction between CS2 and hydrogen is incomplete, leading to an accumulation of carbon disulfide. This affects the sulfidation process, resulting in incomplete sulfidation; moreover, during the gas release phase later on, overheating can occur (as the sulfidation reaction takes place simultaneously with the conversion reaction). With an excess of hydrogen, hydrogen reduction reactions are likely to occur, reducing the active components to elemental cobalt and molybdenum. 9. The amount of carbon disulfide added should not be too much, as excess amounts will accumulate. 6. Deep sulfidation of the catalyst: If an open-type gasification furnace is used, sulfur can be added to the crude gas for sulfidation; during the deep sulfidation stage, the pressure can be increased slightly to facilitate this process.