Ammonia-Ammonium Bisulfate

Ammonium sulfate [7783-20-2], (NH 2 U4, is a white, soluble, crystalline salt having a formula wt of 132.14. The crystals have a rhombic stmcture d is 1.769. An important factor in the crystallization of ammonium sulfate is the sensitivity of its crystal habit and size to the presence of other components in the crystallizing solution. If heated in a closed system ammonium sulfate melts at 513 2° C (14) if heated in an open system, the salt begins to decompose at 100°C, giving ammonia and ammonium bisulfate [7803-63-6], NH HSO, which melts at 146.9°C. Above 300°C, decomposition becomes more extensive giving sulfur dioxide, sulfur trioxide, water, and nitrogen, in addition to ammonia. 

The oxime is converted to caprolactam by Beckmann rearrangement neutralization with ammonia gives ca 1.8 kg ammonium sulfate per kilogram of caprolactam. Purification is by vacuum distillation. A no-sulfate, extraction process has been described, but incineration of the ammonium bisulfate recovers only sulfur values and it is not practiced commercially (14). 

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). 

The organic phase was evaporated and the residue dissolved in chloroform. A portion of the chloroform solution was spotted on silica gel plates which were then developed in chloroform methanol ammonia (89 10 1). After development, the plate was air dried and sprayed with a 2M aqueous solution of ammonium bisulfate. After the plate was air dried for 1 hour, the fluorescent spot representing triprolidine was quantitated with a spectrodensitometer in the reflectance mode with 300 nm excitation and emission above 405 nm. With... 

Aqueous solutions of ammonium sulfate and ammonium bisulfate were deposited on Fluoropore filters, placed in the direct insertion probe, and analyzed in the chemical ionization mode (H2O reagent) gas. The samples were heated from 100°C to 330 C at 15 C/minute. No sample ions were observed under these anlaysis conditions, even when several micrograms of ammonium salts were analyzed. The thermal decomposition of ammonium salts of sulfate has been the subject of many studies. (29,30) Some pathways include sulfuric acid production at one stage of the decomposition while others suggest ammonia, SO2 and SO3 are the products. None of these accurately simulate the conditions (temperature, pressure, gas flow) present in our chemical ionization source. However, no sulfuric acid ions (H3SO4+, etc.) were ob-served... 

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

Ammonia slip on large units like an FCCU translates to wasted chemical expense with no benefit to the refiner. Excess ammonia in a high temperature SCR will oxidize to create NO, which is counter to the intended purpose of the unit. Excess ammonia in a low temperature SCR will tend to form ammonium bisulfate (ABS) per Figure 17.9. 

In cases in which the space charge across the electrical field was insufficiently intense for proper charge buildup, it was found that ammonia injection improved the capturability of the fly ash (14)- Other studies confirmed the applicability of sulfuric acid, ammonium sulfate and ammonium bisulfate as useful conditioners (15). 

Sulfate particles are usually associated with ammonium occasionally larger particles involving calcium or other crustal elements are found. The acidity of sulfate particles will depend on their source and the extent of contact with ambient ammonia. In the Eastern U.S., the average composition seems to vary between letovicite in the summer [ (NH )3H(S0 )2] and ammonium bisulfate in the fall [NH HSO ] (17). Free H2S0A is found on occasion. 

SAROX A process for utilizing the waste ammonium bisulfate from the manufacture of methyl methacrylate. High-temperature pyrolysis yields ammonia and sulfur trioxide. Developed by ICI and Air Liquide. 

Ammonium Sulfate. The colorless, crystalline ammonium sulfate cannot be melted at atmospheric pressure without decomposition at 508 K, releasing ammonia and forming NH4HSO4. After cleavage of water, ammonium bisulfate (NH4128207 is left. However, the ammonia vapor pressure of pure, anhydrous ammonium sulfate is effectively zero up to 350K. Above 573 K, decomposition yields N2, SO2, S03,and H2O in addition to ammonia. ... 

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. 

S. Matsuda, T. Kamo, A. Kato, F. Nakajima, Deposition of ammonium bisulfate in the selective catalytic reduction of nitrogen oxides with ammonia, Ind, Eng, Chem. Prod, Res, Develop, 2I A% (1982). 

The problem is operation below the freezing point of ammonium bisulfate. This results in deposition on the catalyst. At the end of this section is a phase-chart showing the deposition temperature of both ammonium sulfate and ammonium bisulfate, as a function of SO3 and ammonia concentrations. 

ACIDO SULFAMICO (Spanish) (5329-14-6) Violent reaction with chlorine, nitric acid. Violent reaction with strong bases, chlorine, fuming nitric acid. Aqueous solution is a strong acid in elevated temperatures, it hydrolyzes to ammonium bisulfate. Incompatible with alkylene oxides, aliphatic amines, alkanolamines, amides, ammonia, epichlorohydrin, organic anhydrides, isocyanates, metal nitrates/nitrites, oxidizers, vinyl acetate, water. 

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. 

Aside from the hazards posed by HCN, this method uses a large volume of hazardous anhydrous sulfuric acid, which poses a terrorism risk (see sections on sulfuric acid and sulfur dioxide). It also generates a large volume of acidic ammonium bisulfate (NH4HSO4), typically as much as 2.5 kg of ammonium bisulfate for every kg of product. This waste acid is either treated with ammonia for conversion to... 

Matsuda S, Kamo T, Kato A, Nakajima F, Kumura T, Kuroda H (1982) Deposition of Ammonium Bisulfate in the Selective Catalytic Reduction of Nitrogen Oxides with Ammonia. Ind. Eng. Chem. Prod. Res. Dev. 21(l) 48-52... 

Aluminum chloride, 26% Aluminum hydroxide Aluminum nitride Ammonia, dry vapor Ammonium acetate solution Ammonium bisulfate Ammonium bromide Ammonium carbonate Ammonium chloride, 10% Ammonium dichloride Ammonium hydroxide Ammonium hydroxide vapor Ammonium molybdate Ammonium nitrate Argon... 

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). 

The resulting liquor is Stripped with air or steam to remove the SO2 and is then fed to a crystallizer for the production of ammonium sulhite crystals. The crystals are then decomposed by heating to approximately 700°P. The deconqtosition reaction produces ammonium bisulfate for acidulation and ammonia for recycle to the process in accordance with the following reaction ... 

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