What to dry H2S with 30, what to dry with H2S

Hydrogen sulfide gas can be dried using phosphorus pentoxide or anhydrous calcium chloride.

Do not use concentrated sulfuric acid (remember) and do not use alkaline desiccant (such as soda lime). Because hydrogen sulfide is acidic and very reducible.

The desiccant you are looking for should pay special attention to its reducing and acidic properties. Therefore, alkaline desiccant with strong oxidizing properties is not good. Among the common desiccant, the strong oxidizing is concentrated sulfuric acid, and the alkaline is alkali lime, sodium hydroxide, solid quicklime, etc.

Therefore, the desiccant for drying hydrogen sulfide can choose phosphorus pentoxide, calcium chloride, silica gel, etc.

Phosphorus pentoxide. Because hydrogen sulfide is acidic and very reducible, concentrated sulfuric acid cannot be used, nor soda lime can be used.

Phosphorus pentoxide.

It is a neutral desiccant and does not react with general acids and bases.

It is very reductive, oxidative, and very weak.

In short, very inert.

Silica gel reacts with hydrogen sulfide and turns black.

Is anhydrous copper sulphate OK?

NH3 is an alkaline gas capable of reacting with acidic concentrated sulfuric acid.

nh3+h2so4=nh4hso4

Note: Concentrated H2SO4 does not oxidize NH3!

H2S is reducible, and concentrated H2SO4 has strong oxidation and can oxidize it, and generally the two will react as follows

h2s+h2so4=2h2o+so2+s(s)

aThere are two reasons for this.

1.The other three are alkaline substances and cannot be dried with sour potato celery gas!!

2.Concentrated sulfuric acid has strong oxidizing property and cannot dry reducing gases, so it cannot dry H2S, but it can be sold for the first time to dry SO2

Concentrated sulfuric acid desiccant.

1.Generally speaking, acid desiccant cannot dry alkaline gas, but can dry acid gas and neutral gas; However, this is only considered from the perspective of acid-base reaction, and some particularities other than the law should also be taken into account. If there is a redox reaction between the gas and the desiccant, or the formation of complexes, adducts, etc., the desiccant cannot be used to dry the gas.

2.It should also be noted that reducing gases such as H2S, Br2H, and I2H cannot be dried with concentrated sulfuric acid, because the two will undergo redox reactions, such as H2S+H2SO4=2H2O+SO2+S

Concentrated H2SO4 is acidic, so it cannot dry alkaline gases, such as NH3

Concentrated H2SO4 has strong oxidizing properties, so it cannot dry reducing gases, such as H2S, HBR, HI, etc.

Gases that can react with sulfuric acid, such as ammonia, cannot be dried.