Desulfurization of feed gas in ammonia synthesis production
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How many methods are there for desulfurizing the feed gas in ammonia synthesis production nowadays? Our company preheats the material to around 360 degrees first, then carries out cobalt-molybdenum hydrogenation, and finally uses two series-connected zinc oxide desulfurization tanks for desulfurization. Are there any other methods for desulfurization? Thank you! This post was last edited by pfzyf on 2009-2-1 22:54.]
Desulfurization is divided into two categories: dry desulfurization and wet desulfurization. 1. During the gas purification process, wet desulfurization can be used first to remove over 90% of the inorganic sulfur; the desulfurization liquid can be regenerated and reused, while sulfur is produced as a by-product. The advantage of this method is its cost-effectiveness, while the disadvantages are low precision and low efficiency for organic sulfur. There are many options available for desulfurizing agents, including cobalt phthalocyanine compounds, DDS, divalent manganese salts plus hydroquinone, etc. The choice of desulfurizing agent can be determined based on actual requirements. 2. Dry desulfurization: Sulfur is converted into an inorganic form through conversion catalysts such as iron-molybdenum and cobalt-molybdenum, and desulfurization is achieved via the absorption by desulfurizing agents like iron oxide and zinc oxide. Transformation and desulfurization can be combined, with the specific approach being gradual transformation, gradual absorption, followed by further transformation and absorption. This method is characterized by high desulfurization accuracy, which can go below 0.1PPM. The disadvantage is the high cost of desulfurization. During the purification of gas, for those with a high sulfur content, a combination of two methods should be used to achieve optimal desulfurization and economic efficiency.
It mainly involves the conversion of organic sulfur; generally, the temperature is maintained between 280 and 380 degrees, and it can even reach around 450 degrees.
Generally, wet desulfurization is first used to remove the majority of inorganic sulfur, followed by dry desulfurization to achieve precise desulfurization.
Continuing from before, the most commonly used desulfurization method nowadays is low-temperature methanol washing. This method offers high desulfurization efficiency and does not require the use of additional devices for removing organic sulfur. If other desulfurization methods are employed, devices for removing organic sulfur such as zinc oxide or iron oxide are needed; activated carbon is also widely used in this regard.