Investigation into the unexplained increase in hydrogen sulfide at the outlet of the purification unit
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Previously, the hydrogen sulfide level in the purification unit was quite good, but after the sudden change to another type of coal, its concentration soared from around 0.07 to 0.13, and it has since remained at around 0.18. As for the conversion unit, the levels of hydrogen sulfide and COS in the gas exiting that unit have remained stable. I would like to know the reasons for the excessive hydrogen sulfide levels
Were the contents of thiols and thioethers analyzed in the lean methanol and shift outlet samples?
It must be the sulfur in the coal; there’s no doubt about that – it’s definitely due to the change in coal.
1. Total sulfur content in coal quality analysis: compare before and after the replacement to observe any changes in sulfur levels； 2. Gas analysis before purification.
Additionally, analyze the ammonia content.
The reason is likely due to changes in the form of sulfides and the total sulfur content in the process gas caused by the coal change. Let’s first analyze the sulfides in the process gas before purification
Analyze the methane content in the system
Is the sulfur content at the top of the tower above the limit? Let’s see what the sulfur content is in the gas coming out of the desulfurization section Since the sulfur content in the raw material has increased significantly, it is suspected that the amount of washing is insufficient. Since the transformation process remains unchanged, it is estimated that there will be no excess levels of thiols or thioethers.
Thiophene is more difficult to decompose than thiol; let’s consider taking a sample for analysis
It is recommended to conduct a full analysis comparison, rather than comparing only sulfides