Weekly Topic: What poisons must be guarded against in catalysts during normal production? Methanol segment from 05-02 to 05-09, 2016
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For the methanol section’s weekly topics, we encourage all members to participate actively. The purpose of this activity is to review the knowledge we have already learned; through answering questions, we can improve our skills and broaden our knowledge base, help us remember what we know, recall what we have forgotten, and deepen discussions on controversial topics, thus achieving common progress. We would appreciate it if you could actively share any opinions or suggestions, so that we can work together to improve this methanol section and create a better platform for communication for everyone! ! There will be a reward for everyone who answers; great content is available upon reply. Weekly Topic: What poisons must be guarded against in catalysts during normal production? What is the effect of catalyst heating and reduction quality on the catalyst? For the methanol sector, from 05-02 to 05-09, 2016, what poisons need to be guarded against regarding catalysts during normal production? What is the effect of catalyst heating and reduction quality on the catalyst? Answer: 1) Copper catalysts are highly sensitive to sulfur poisoning, as the reaction between hydrogen sulfide and copper produces CuS and Cu2S, which **reduces the catalyst’s activity and shortens its service life; therefore, the hydrogen sulfide content in the gas fed into the tower must be kept below 0.1PPm. 2) CL- in process water also poses a significant threat to copper catalysts, and it can cause corrosion in equipment and pipelines; therefore, primary deionized water is generally used for process water. 3) Ammonia carried in the gas entering the tower reduces the catalyst’s activity, causing temporary poisoning; if the ammonia content is reduced or eliminated, the catalyst’s activity will recover, but it will not return to its original level. 4) Oil decomposes into carbon and high-carbon gums at high temperatures, which settle on the surface of the catalyst and block its micropores; moreover, elements such as sulfur, phosphorus, and arsenic in the oil can permanently poison the catalyst. The quality of catalyst reduction upon heating plays a decisive role in the catalyst’s service life in the future. Catalysts with good reduction quality have small grains, numerous internal voids, and a large surface area; such catalysts exhibit high reactivity, a uniform temperature distribution within the bed, and a long service life when used in normal production processes.
Which poisons must catalysts be protected against during normal production? Answer: 1) Copper catalysts are highly sensitive to sulfur poisoning, as hydrogen sulfide reacts with copper to form CuS and Cu2S, which **reduces the catalyst’s activity and shortens its service life; therefore, the hydrogen sulfide content in the gas fed into the tower must be kept below 0.1PPm. 2) CL- in process water also poses a significant threat to copper catalysts, and it can cause corrosion in equipment and pipelines; therefore, primary deionized water is generally used for process water. 3) Ammonia carried in the gas entering the tower reduces the catalyst’s activity, causing temporary poisoning; if the ammonia content is reduced or eliminated, the catalyst’s activity will increase again, but it will not return to its original level. 4) Oil decomposes into carbon and high-carbon gums at high temperatures, which settle on the surface of the catalyst and block its micropores; moreover, sulfur, phosphorus, arsenic, and other elements in the oil can permanently poison the catalyst. What is the effect of catalyst heating and reduction quality on the catalyst? Answer: The quality of catalyst reduction upon heating plays a decisive role in the catalyst’s service life in the future. Catalysts with good reduction quality have small grains, numerous internal voids, and a large surface area; such catalysts exhibit high reactivity, a uniform temperature distribution within the bed, and a long service life when used in normal production processes.
Common poisons include sulfur, chlorine, oil, ammonia, metal carbonyl compounds, etc. The quality of catalyst reduction upon heating plays a decisive role in the catalyst’s service life in the future. Catalysts with good reduction quality have small grains, numerous internal voids, and a large surface area; such catalysts exhibit high reactivity, a uniform temperature distribution within the bed, and a long service life when used in normal production processes.
Toxin prevention: 1. Inactivation by cation exchange； 2. Deactivation by hydrolysis of nitrides ； 3. Loss of sulfonic acid group ； 4. Clogging of catalyst pores ； Effect of catalyst reduction quality on the catalyst: Catalysts with good reduction quality have smaller grains, more internal voids, and better reaction efficiency ； Conversely, it is the opposite.
Answer: 1) Copper catalysts are highly sensitive to sulfur poisoning, as hydrogen sulfide reacts with copper to form CuS and Cu2S, which **reduces the catalyst’s activity and shortens its service life; therefore, the hydrogen sulfide content in the gas fed into the tower must be kept below 0.1PPm. 2) CL- in process water also poses a significant threat to copper catalysts, and it can cause corrosion in equipment and pipelines; therefore, primary deionized water is generally used for process water. 3) Ammonia carried in the gas entering the tower reduces the catalyst’s activity, causing temporary poisoning; if the ammonia content is reduced or eliminated, the catalyst’s activity will increase again, but it will not return to its original level. 4) Oil decomposes into carbon and high-carbon gums at high temperatures, which settle on the surface of the catalyst and block its micropores; moreover, sulfur, phosphorus, arsenic, and other elements in the oil can permanently poison the catalyst. What is the effect of catalyst heating and reduction quality on the catalyst? Answer: The quality of catalyst reduction upon heating plays a decisive role in the catalyst’s service life in the future. Catalysts with good reduction quality have small grains, numerous internal voids, and a large surface area; such catalysts exhibit high reactivity, a uniform temperature distribution within the bed, and a long service life when used in normal production processes.
1. Copper catalysts are highly sensitive to sulfur poisoning, as the reaction between hydrogen sulfide and copper produces CuS and Cu2S, which **reduces the catalyst’s activity and shortens its service life; therefore, the hydrogen sulfide content in the gas fed into the tower must be kept below 0.1PPm； 2. The Cl- in process water also poses a serious threat to copper catalysts, and it can cause corrosion in equipment and pipelines; therefore, primary deionized water is generally used for process water ； 3. Ammonia present in the gas entering the tower reduces the catalyst’s activity, causing temporary poisoning; if the ammonia level is reduced or eliminated, the catalyst’s activity will increase again, but it will not return to its original level ； 4. At high temperatures, oil decomposes into carbon and high-carbon gums, which deposit on the surface of the catalyst and block its micropores; moreover, elements such as sulfur, phosphorus, and arsenic in the oil can permanently poison the catalyst. The quality of catalyst reduction upon heating plays a decisive role in the catalyst’s lifespan over time. Catalysts with good reduction quality have small grains, numerous internal pores, and a large surface area; such catalysts exhibit high reactivity, a uniform temperature distribution within the bed, and a longer service life when used in normal production processes.