How to remove H2S from the air?
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We are working on a project that requires compressed air for its processes, but H2S in the air can poison the catalysts. The air at the project site has a strong H2S odor (the exact concentration has not been determined). How can H2S be removed from air in the air compression process? Thank you first!
Add some SO2, and H2S will be removed.
Is there any specific process to remove H2S before air enters the compressor?
Also, I would like some information on the mechanism of palladium catalyst poisoning.
The alkali washing followed by drying process can address H2S issues
Is air being introduced into the alkali? Besides H2S, what kind of base is used, and what is its concentration? What equipment is used to dry air after removing H2S? Our air consumption is 200 Nm3/h, and we plan to use a centrifugal air compressor; the air is used in the oxidation process of hydrogen peroxide production. This post was last edited by hkmhg on 2007-12-18 11:47]
It can be absorbed with diethanolamine before compression; if the sulfur content is high, a cobalt-molybdenum catalyst can be considered for removal
It is recommended that you first conduct a gas composition analysis. If the H2S content is high, carry out alkali washing before compression; a 25% NaOH solution can be used for the alkali washing ； If the H2S content is low, activated carbon adsorption can be used. Both can also be used together, and vapor-liquid separation should be carried out to remove water.
Ammonia synthesis plants generally use cobalt-molybdenum and zinc oxide to remove inorganic sulfur. For such issues, you can consult design institutes like Tianchen and Global.
The poster should provide the H2S content in the air； Maximum H2S content requirement to avoid catalyst poisoning ； Only then can a specific process plan be developed. Preliminary suggestions: 1. NaOH alkaline washing (H2S concentration can be reduced to 20ppm) ； 2. PSA pressure swing adsorption ； 3. Alkylamine method ； 4. CLINSULF method ； 5. ZnO/Fe2O3 method ；
Zinc oxide can be used for desulfurization; if organic sulfur is present, cobalt-molybdenum and hydrogen are required to convert it. The specific procedure is as follows: the gas is first fed into a compressor for compression. The compressed gas is then subjected to cobalt-molybdenum hydrogenation and zinc oxide desulfurization. After desulfurization, the gas enters a flash tank where water is separated out, after which it can be used. In the desulfurization process during ammonia synthesis, compression is carried out first followed by desulfurization, so that the compressor is not affected by water.
. . . For gases that use the atmosphere as their gas source, the H2S level should not be high; otherwise, people cannot live in the surrounding area. It can be removed by using alkalis. .
200 Nm3/h – is a centrifugal air compressor intended to be used??? Is that a mistake? In fact, using activated carbon adsorption (or + molecular sieve drying) at the compressor outlet is more than sufficient to meet the requirements. Could the H2S content in the air be very high? Just place the air intake at a higher position.
Personally, I think using slaked lime solution yields the same results; there’s no need to use NaOH, as its cost is relatively high. Just as is done routinely for desulfurization and dechlorination, the flow rate can be controlled during the alkali washing process to achieve the desired results. Additionally, alkali washing can be carried out using spraying, with fillers such as layers of crushed plastic being used to increase contact and thus achieve the desired outcomes
The concentration of sulfur compounds in the gas should be analyzed and measured first; subsequently, depending on the required level of purity, it can be decided whether to use a wet or dry method.
First, we need to analyze the issue of hydrogen sulfide concentration; it’s not just a catalyst problem, but it also relates to safety concerns.
The concentration of hydrogen sulfide in the air is subject to strict limits; I’m curious about how the disease control agencies in your area handle this. The commonly used process is alkali washing first, followed by adsorption; drying can also be added, and the necessary equipment is available. For small projects, we can help you design and manufacture the processes and equipment for environmental protection equipment factories.
Using alkaline water is not safe; it is recommended to use SO2
If the concentration is low, activated carbon can be used for absorption; for higher concentrations, alkali washing followed by drying is applied. As for SO2, it’s unclear how to control its amount – will an excess of SO2 have any impact on subsequent steps?
Zinc oxide is generally used to remove H2S
Absorb with KOH at a certain concentration