Ammonia bisulfate formation

Oxidation of SO2 to SO3 Ammonia oxidation to NO Sulfuric acid formation Ammonium bisulfate formation ... 

Other problems that can be associated with the high dust plant can include alkaH deterioration from sodium or potassium in the stack gas deposition on the bed, calcium deposition, when calcium in the flue gas reacts with sulfur trioxide, or formation and deposition of ammonium bisulfate. In addition, plugging of the air preheater as weU as contamination of flyash and EGD wastewater discharges by ammonia are avoided if the SCR system is located after the FGD (23). 

In continental air sulfate tends to be associated with finer particles, and as ammonia is more likely to be present in the air this can neutralize the sulfuric acid with the formation of ammonium sulfate- or bisulfate-containing particles over land. Sulfuric acid can displace chloride from seasalt aerosols and represent a source of hydrogen chloride ... 

Once formed, sulfates readily combine with atmospheric ammonia to form ammonium sulfate ((NH4)2S04) or ammonium bisulfate (NH4HSO4). Formation of these species can be a significant sink of atmospheric ammonia. As mentioned above, the interaction between sulfates, nitrates, and ammonia is a cause of nonlinearity in aerosol source-receptor relationships. 

Additional examples of synthetic application of periodic acid as an oxidant include the oxidative iodination of aromatic compounds [1336-1341], iodohydrin formation by treatment of alkenes with periodic acid and sodium bisulfate [1342], oxidative cleavage of protecting groups (e.g., cyclic acetals, oxathioacetals and dithioacetals) [1315, 1343], conversion of ketone and aldehyde oximes into the corresponding carbonyl compounds [1344], oxidative cleavage of tetrahydrofuran-substituted alcohols to -y-lactones in the presence of catalytic PCC [1345] and direct synthesis of nitriles from alcohols or aldehydes using HsIOe/KI in aqueous ammonia [1346],... 

This is in an unscrubbed plume. Now, concerning ammonia, you ae not really talking about ammonia as a catalyst for sulfate formation. The actual process is SO2 to sulfuric acid, followed by ammonia neutralization. The theory about SO2, water, ammonia catalysis is being questioned. The real process seems to be SO2 to sulfuric acid, then reaction with ammonia to form ammonium sulfate or ammonium bisulfate. In fact, in scavenging the sulfate, as the particle size increases, the scavenging efficiency also increases. Sulfuric acid aerosols are submicron particulates for which scavenging is very inefficient (Marsh, Atmos. Environ. 12 401-406, 1978). So what you are finding in a rain droplet is perhaps what is below the cloud or before the condensation nucleus stabilizes. 

When ammonia is present in the atmosphere, the washout SO2, partially transformed into sulfuric acid can be neutralized more or less by forming ammonium salts. Now in some parts of The Netherlands I found that because of the presence of peroxides and ozone and perhaps other oxidizing agents, the content of ammonia in the ambient air and the presence of ammonium in precipitation was very small to negligible. When ammonia in the atmosphere is present, by the formation of ammonium bisulfates in precipitation, theoretically, the pH can reach a minimum value of about 2.6. In certain parts of The Netherlands, due to lack of sufficient ammonia in the atmosphere I suppose, in single precipitation samples before 1974 I found pH values between 2 and 2.6. 

Sulfur dioxide or bisulfites are rarely used in combination with nitrites, because their reactions in acidic media yield sulfonates of either hydroxylamine or ammonia, which destroys the preservative activity of the individual additives. The reaction of alkali metal nitrites with bisulfite at lower temperatures leads to the formation of hydroxylamine N, JV-disulfonate, H0N(S03)2, which is hydrolysed to hydroxylamine JV-sulfonate, HONHSOj and further to hydroxylamine (H2NOH). At elevated temperatures complete substitution proceeds with the formation of ammonia JV-trisulfonate, N(S03)j , which is hydrolysed to sulfa-mate, H2NSOj . Subsequent reaction of sulfamate with nitrous acid leads to production of bisulfate ion and nitrogen gas ... 

Another separation strategy uses the formation of diammonium succinate, where the ammonium ion is used to control the pH in the fermentation. The diammonium succinate can be concentrated and reacted with a sulfate ion at low pH to yield ammonium sulfate and succinic acid. Succinic acid has very low solubility in aqueous solutions with a pH below 2 and can be crystallized. The succinic acid can be purified with methanol, and the ammonium sulfate is thermally cracked into ammonia and ammonium bisulfate. The ammonia can be fed back into the fermenter, and the ammonium bisulfate can be recycled for use in succinic acid crystallization (Berglund et al. 1999). 

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