Acid continued sulfurous

During my Cleveland years, I also continued and extended my studies in nitration, which I started in the early 1950s in Hungary. Conventional nitration of aromatic compounds uses mixed acid (mixture of nitric acid and sulfuric acid). The water formed in the reaetion dilutes the acid, and spent aeid disposal is beeoming a serious environ-... 

Sulfamic acid [5329-14-6] (amidosulfuric acid), HSO2NH2, molecular weight 97.09, is a monobasic, inorganic, dry acid and the monoamide of sulfuric acid. Sulfamic acid is produced and sold in the form of water-soluble crystals. This acid was known and prepared in laboratories for nearly a hundred years before it became a commercially available product. The first preparation of this acid occurred around 1836 (1). Later work resulted in identification and preparation of sulfamic acid in its pure form (2). In 1936, a practical process which became the basis for commercial preparation was developed (3,4). This process, involving the reaction of urea with sulfur trioxide and sulfuric acid, continues to be the main method for production of sulfamic acid. 

Distillation boundaries for continuous distillation are approximated by simple distillation boundaries. This is a very good approximation for mixtures with nearly linear simple distillation boundaries. Although curved simple distillation boundaries can be crossed to some degree (16,25—30,32,33), the resulting distillation sequences are not normally economical. Mixtures such as nitric acid—water—sulfuric acid, that have extremely curved boundaries, are exceptions. Therefore, a good working assumption is that simple distillation boundaries should not be crossed by continuous distillation. In other words, for a separation to be feasible by distillation it is sufficient that the distillate and bottoms compositions He in the same distillation region. 

Forms azeotropic mixts with butyl ale, acetic acid, heptane, toluene, nitroethane, perchioro-ethylene, w, etc. Prepn is by reacting propyl ale with coned nitric acid (d 1.41g/cc) dissolved in ethylacetate at 20°, followed by distn of the product. NPN can also be preod bv reacting a continuous stream of propyl ale below the surface of stirred mixed acid (20% nitric acid, 68% sulfuric acid and 12% w by wt) in a cooled (0—5°) open stainless steel vessel. Addnl mixed acid is also simultaneously introduced at about a third of the depth of the liq. An overflow pipe maintains a constant reactant level and the effluent prod is sepd, washed with 10% aq Na carbonate soln and dried by passage thru a Filtrol packed tower. Contact time of reactants can vary from 0.6 to 15 mins using about 50% isopropanol at 0° to yield 66.5% NPN (Ref 3b)... 

Indole-3-Acetic Acid. Dissolve 21.6 g of phenylhydrazine in 300 ml 0.3 N sulfuric acid. To this solution add 9.8 g of coned sulfuric acid. With stirring and heating to 100°, add dropwise 11.6 g of methyl-beta-formyl-propionate in 300 ml of 0.3 N sulfuric acid. Continue the heating and gentle stirring for 6 hours to get about 14 g of indole-3-acetic acid. This is from CA, 72, 66815 (1970). 

Some organosulfur compounds can function as fuel antioxidants by acting to decompose hydroperoxides. Organosulfides are believed to react with hydroperoxides to form sulfoxides. The sulfoxides then further react with hydroperoxides to form other more acidic compounds. These newly formed acids continue the process of decomposing and reaction with hydroperoxides. Thus, organosulfur compounds function in the process oxidation inhibition through hydroperoxide decomposition. However, in most fuel applications, sulfur-containing antioxidants are not utilized. 

In contrast to the sulfuric acid process, regeneration of the catalyst in hydrofluoric acid alkylation is continuous. During processing, both hydrofluoric acid and sulfuric acid... 

Ethyl Acetate. The production of ethyl acetate by continuous esterification is an excellent example of the use of azeotropic principles to obtain a high yield of ester (2). The acetic acid, concentrated sulfuric acid, and an excess of 95% ethyl alcohol are mixed in reaction tanks provided with agitators. After esterification equilibrium is reached in the mixture, it is pumped into a receiving tank and through a preheater into the upper section of a bubblecap plate column (Fig. 5). The temperature at the top of this column is maintained at ca 80°C and its vapor (alcohol with the ester formed and ca 10% water) is passed to a condenser. The first recovery column is operated with a top temperature of 70°C, producing a ternary azeotrope of 83% ester, 9% alcohol, and 8% water. The ternary mixture is fed to a static mixer where water is added in order to form two layers and allowed to separate in a decanter. The upper layer contains ca 93% ethyl acetate, 5% water, and 2% alcohol, and is sent to a second recovery or ester-drying column. The overhead from this column is 95—100% ethyl acetate which is sent to a cooler and then to a storage tank. This process also applies to methyl butyrate. 

Generally, ink dyes for ink jet applications and writing, drawing, or marking materials are selected from food, acid, direct, sulfur, and reactive dyes. The choice of dye depends on the application and the ink used, whether it is aqueous, solvent based, or hot melt, and on the printer type continuous ink jet or drop-on-demand, piezo or thermal inkjet. 

The necessity for the continuous removal of water can be avoided by operating in a system composed of an aqueous and a non-aqueous layer. When a mixture of adipic acid, methanol, sulfuric acid, and ethylene chloride is heated, dimethyl adipate passes into the ethylene chloride layer the lower layer contains the water (19). 

There is a strong incentive for the development of a continuous fixed bed catalytic process for regioselective nitration of aromatics. Solid acid catalysts are able to carry out the reaction, but, for most of them, selectivities are similar to those obtained using nitric acid plus sulfuric in homogeneous phase. 

Acid hydrolysis of starch is conducted with hydrochloric acid or sulfuric acid, mainly in a continuous process, yielding syrups with 20 to 68 DE. The process consists of the acidification of a starch slurry with hydrochloric acid to a pH of about 1.8 to 1.9, and pumping the suspension into a converter (autoclave) where live steam is gradually admitted to a pressure of 30 to 45 psi. Converted liquids are neutralized with sodium carbonate to a pH of 5 to 7. Proteins, lipids, and colloidal matter are separated as sludge. Pigments are eliminated with activated carbon and minerals with ion exchangers. The raw juice, thus obtained, is evaporated under a vacuum (falling-film evaporator) up to a solids content of 70 to 85 percent. 

In a 10-mL Erlenmeyer flask, place 0.5 g of triphenylmethanol, grind the crystals to a fine powder with a glass stirring rod, and add 5 mL of concentrated sulfuric acid. Continue to stir the mixture to dissolve all of the alcohol. Using a Pasteur pipette, transfer the sulfuric acid solution to 30 mL of ice-cold methanol in a 50-mL Erlenmeyer flask. Use some of the cold methanol to rinse out the first tube. Induce crystallization if necessary by... 

More recent studies confirm the value of added ascorbic acid in wine for improvement of quality (680-683), in champagne production (684), in converting ordinary wine into sherry wine (685), in eliminating the need for heat sterilization of sulfur dioxide (686), and in the production of hot bottled Moselle wine (687). Reports on combined use of ascorbic acid and sulfur dioxide indicate its continued practical significance (688-691). 

The eruption of a volcano is accompanied by emissions of water vapour (>70% of the volcanic gases), CO2 and SO2 plus lower levels of CO, sulfur vapour and CI2. Carbon dioxide contributes to the greenhouse effect, and it has been estimated that volcanic eruptions produce 112 million tonnes of CO2 per year. Levels of CO2 in the plume of a volcano can be monitored by IR spectroscopy. Sulfur dioxide emissions are particularly damaging to the environment, since they result in the formation of acid rain. Sulfuric acid aerosols persist as suspensions in the atmosphere for long periods after an eruption. The Mount St Helens eruption occurred in May 1980. Towards the end of the eruption, the level of SO2 in the volcanic plume was 2800 tonnes per day, and an emission rate of p 1600 tonnes per day was measured in July 1980. Emissions of SO2 (diminishing with time after the major eruption) continued for over two years, being boosted periodically by further volcanic activity. 

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