【Q&A Question 017】2017.01.17
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This post was last edited by 955559 on 2017-7-21 at 12:52. [Q&A Question No. 017] 2017.01.17: What are the effects of high H2S levels in recycled hydrogen? The reference answers will be visible after responding; scoring is awarded by identifying the key points. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) (1) If there is a high amount of H2S in the recycled hydrogen, it will corrode the pipeline equipment, leading to the accumulation of rust on the catalyst bed and an increase in pressure drop. Additionally, from a chemical equilibrium perspective, a high H2S content in the recycled hydrogen is not conducive to the desulfurization reaction. (2) The high H2S content in the recycled hydrogen affects its purity; lower hydrogen purity impacts the hydrogenation reaction and thus the quality of the product. 2017 Q&A Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657794-1-1.html 2016 Q&A Summary Thread (updates completed) http://bbs.hcbbs.com/thread-1597792-1-1.html Xinchang Cup – 2016 Haichuan Top 10 Selection – Please recommend candidates http://bbs.hcbbs.com/thread-1654112-1-1.html Third Round of Haichuan Outstanding Management Members Selection http://bbs.hcbbs.com/thread-1655902-1-1.html (Source: Haichuan Chemical Industry Forum)
1. A high hydrogen sulfide content inhibits the aromatic saturation that occurs during the hydrodesulfurization reaction, resulting in a decrease in catalyst activity. 2. Large amounts of hydrogen sulfide cause corrosion of the equipment, leading to damage and posing a risk to safe production. 3. In low-temperature areas, the amount of sulfamide salts increases, causing crystallization that blocks pipelines and leads to an increase in pressure drops within the reaction system……and so on
1. It will inhibit the desulfurization of the reaction oil, affecting product quality； 2. It will affect the hydrogen partial pressure ； 3. Severe corrosion of equipment pipes ； 4. It will lead to an increase in the inorganic sulfur content in the hydrogenated oil, affecting product quality ；
1. Increased equipment corrosion 2. Reduction in the purity of recycled hydrogen 3. Increase in the molecular weight of recycled hydrogen, leading to higher compressor power consumption
Reducing the hydrogen partial pressure exacerbates equipment corrosion
Excessively high H2S partial pressures significantly suppress the hydrodesulfurization activity and aromatic saturation capacity of catalysts; in particular, precious metal catalysts turn into sulfided states at high H2S partial pressures, resulting in a decrease in their activity. After the hydrocracking products leave the cracking bed, the trace amounts of olefins present in them still react with H2S to form thiols, thereby increasing product corrosion. If the sulfur content in the raw material is too high, not only will NH4HS be formed and clog the system, but the corrosion rate of the equipment will also increase
1. An excessively high H2S partial pressure in the recycle hydrogen has a significant inhibitory effect on the hydrodesulfurization activity and aromatic saturation capacity of catalysts; in particular, precious metal catalysts turn into sulfided states at high H2S partial pressures, resulting in a decrease in their activity. 2. After the hydrocracking products leave the cracking bed, the very small amount of olefins present still reacts with H2S to form thioalcohols, thereby increasing product corrosion. 3. If the sulfur content in the raw materials is too high, not only will NH4HS be formed and cause blockages in the system, but the corrosion rate of the equipment will also increase. Typically, when the H2S level in the system exceeds 2%, desulfurization measures must be taken to remove H2S from the high-pressure system.
1) If there is a high amount of H2S in the recycled hydrogen, it will corrode the pipeline equipment, leading to the accumulation of rust on the catalyst bed and an increase in pressure drop. Additionally, from a chemical equilibrium perspective, a high H2S content in the recycled hydrogen is not conducive to the desulfurization reaction. 2) The high H2S content in the recycled hydrogen affects its purity; lower hydrogen purity impacts the hydrogenation reaction and thus the quality of the product.
It affects the desulfurization efficiency of circulating hydrogen, which may result in the product having an unsatisfactory sulfur content.