Ammonium bisulfate formation

Ammonium acetates, 2 711-712 Ammonium alum calcination, 2 395 neutralization, 2 430 Ammonium benzoate, 3 634 Ammonium bicarbonate, 2 712-713 Ammonium bifluoride, 2 717-718 Ammonium bisulfate formation, 10 98 Ammonium bromide, 2 714... 

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

The formation of ammonium bisulfate is strongly temperature dependent. Formation is favored at the lower temperatures. The temperature at which ammonium bisulfate is not formed depends strongly on the SO concentration in the exhaust gas. The temperature needed to minimize bisulfate formation has been reported to increase by about I5°C (around about 350°C) when the SO concentration increases from 5 to 15 ppm (23). The formation of the bisulfate is reversible, ie, if the temperature is raised to 20°C above the minimum temperature, the reaction is shifted to result in the decomposition of the bisulfate formed. When chlorides are present, ammonium chlorides can be formed ... 

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 epoxidation method developed by Noyori was subsequently applied to the direct formation of dicarboxylic acids from olefins [55], Cyclohexene was oxidized to adipic acid in 93% yield with the tungstate/ammonium bisulfate system and 4 equivalents of hydrogen peroxide. The selectivity problem associated with the Noyori method was circumvented to a certain degree by the improvements introduced by Jacobs and coworkers [56]. Additional amounts of (aminomethyl)phos-phonic acid and Na2W04 were introduced into the standard catalytic mixture, and the pH of the reaction media was adjusted to 4.2-5 with aqueous NaOH. These changes allowed for the formation of epoxides from ot-pinene, 1 -phenyl- 1-cyclohex-ene, and indene, with high levels of conversion and good selectivity (Scheme 6.3). 

Fouling Salt formation can build-up on the catalyst surface effectively limiting accessibility. Ammonium bisulfate can form at low temperatures. This foulant can be removed by increasing temperature and is considered a temporary poison. 

For the formation of ammonium salts such as ammonium sulfate and ammonium bisulfate on the catalyst surface, the S02 should be first oxidized to S03, and then S03 should react with NH3 and HjO. Since the formation of these ammonium salts depends on the oxidizing ability of the catalyst converting S02 into S03 the deactivating agent deposited on HM-250 catalyst could be formed less than CuHM catalysts as shown in Table 1. 

Methyl methacrylate (MMA) is one of the most important monomers [80-82]. It forms the basis of acrylic plastics and of polymer dispersion paints. The traditional production is by the formation of acetone cyanohydrin, elimination of water and hydrolysis of the nitrile group, followed by the ester formation. In the carbon-carbon bond forming reaction large amounts of excess HCN and ammonium bisulfate are left as waste. Although these problems have been addressed there is still much room for improvement. In particular the number of reaction steps should be reduced and, in order to achieve this, cyanide should be avoided. The building block to replace it is CO. 

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. 

The ACH process has been improved by Mitsubishi Gas [332]. Acetone cyanohydrin is first hydrolyzed to 2-hydroxyisobutylamide with a Mn02 catalyst the amide is then reacted with methyl formate to produce the methyl ester of 2-hydroxyisobutyric acid, with co-production of formamide (this reaction is catalyzed by sodium meth-oxide). The ester is finally dehydrated with an Na-Y zeolite to methyl methacrylate. Formamide is converted into cyanhydric acid, which is used to produce acetone cyanohydrin by reaction with acetone. The process is elegant, since it avoids the co-production of ammonium bisulfate, and no net income of HCN is present. However, there are many synthesis steps, and a high energy consumption. 

Addition of make-up and recycle aqueous methanol (to prevent the formation of dimethyl ether). Esterification in a series of agitated reactors cdoled as described above, after heating of the feed to 100°C and repressurization under OR to 0.7.106 Pa absolute. The thermal level must be selected to prevent the crystallization of ammonium bisulfate. 

The enthalpy and entropy of activation for the formation of sulfamic acid and ammonium bisulfate are ... 

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. 

Ammonium fluosilicate - 658, 672 Ammonium formate - 658 Ammonium hydrogen sulfate (see Ammonium bisulfate)... 

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). 

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 ... 

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