Reviewing the Old to Discover the New (Series 18)
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Short answer: What are the main sulfides contained in the feed gas? Why remove it?
There are various types of sulfides in the feed gas, which can be classified into inorganic sulfides (mainly hydrogen sulfide, H2S) and organic sulfides. Organic sulfides mainly include carbon disulfide (COS), carbon disulfide (CS2), thiols (RSH), and thiophene (C4H4S). Some feed gases also contain small amounts of thioether (R–S–R’) and thiophene derivatives, such as hydrogenated thiophene (C4H8S), etc. Although the sulfur content in the feed gas is low, its hazards are significant. Its presence increases the corrosion of gas on metal equipment and pipelines, and it also causes catalyst poisoning in methanol synthesis, ammonia synthesis, and various purification processes. So it must be removed.
The raw gas contains hydrogen sulfide (H2S) and organic sulfur compounds, which are removed using physical absorbent methods, chemical solvent absorption methods, and physico-chemical solvent absorption methods
Hydrogen sulfide and sulfur dioxide, which are acidic gases, react with water to produce acids that corrode pipes
Sulfur in the feed gas is divided into inorganic sulfur and organic sulfur; inorganic sulfur is H2S, while organic sulfur mainly includes CS2, COS, thiols, thioethers, and thiophenes. Sulfur is a poison for various catalysts. It has a significant impact on the activity of methane conversion and methanation catalysts, medium-temperature shift catalysts, low-temperature shift catalysts, methanol synthesis catalysts, ammonia synthesis catalysts, etc. Sulfides can also corrode equipment and pipelines, causing many problems in subsequent production processes. Therefore, it is essential to remove sulfides from the feed gas. At the same time, sulfur, a by-product, can also be obtained during the purification process.
The sulfides in the feed gas are mainly hydrogen sulfide; in addition, there are organic sulfur compounds such as carbon disulfide, carbonyl sulfide, thiols, thioethers, and phenols. Its content varies greatly depending on the raw materials and their origin. Although the sulfur compound content is not high, hydrogen sulfide and organic sulfur gases can poison catalysts and corrode metal pipes and equipment, posing a serious threat to production; therefore, these sulfur compounds must be removed and these sulfur resources recovered.
The sulfides in the feed gas are mainly hydrogen sulfide; in addition, there are also organic sulfur compounds such as carbon disulfide, carbonyl sulfide, thiols, thioethers, and thiophene. Sulfides in the feed gas can not only corrode equipment and pipelines but also poison catalysts. The catalysts used in the ammonia synthesis process have certain requirements regarding the sulfur compound content in the feed gas.
There is organic sulfur and inorganic sulfur; mainly to protect the system catalyst after protection
The sulfides in the feed gas are mainly hydrogen sulfide; in addition, there are organic sulfur compounds such as carbon disulfide, carbonyl sulfide, thiols, thioethers, and phenols. Sulfur is a poison for various catalysts. It has a significant impact on the activity of methane conversion and methanation catalysts, medium-temperature shift catalysts, low-temperature shift catalysts, methanol synthesis catalysts, ammonia synthesis catalysts, etc. Sulfides can also corrode equipment and pipelines, causing many problems in subsequent production processes. Therefore, it is essential to remove sulfides from the feed gas. At the same time, sulfur, a by-product, can also be obtained during the purification process.
Sulfides in the feed gas: mainly hydrogen sulfide, followed by organic sulfur compounds such as carbon disulfide (CS2), carbon monosulfide (COS), thiol (RSH), thioether (RSR’), and thiophene (C4H4S). Desulfurization methods: Depending on the content and type of sulfides, as well as the desired level of purification, technical requirements, and economic considerations, one or more desulfurization methods can be selected for this purpose. Based on the state of the desulfurizing agent, there are two main categories: dry and wet methods.