Carbonate vaporization, alkali

Processes rendered obsolete by the propylene ammoxidation process (51) include the ethylene cyanohydrin process (52—54) practiced commercially by American Cyanamid and Union Carbide in die United States and by I. G. Farben in Germany. The process involved the production of ediylene cyanohydrin by the base-catalyzed addition of HCN to ethylene oxide in die liquid phase at about 60°C. A typical base catalyst used in diis step was dietliylamine. This was followed by liquid-phase or vapor-phase dehydration of the cyanohydrin. The liquid-phase dehydration was performed at about 200°C using alkali metal or alkaline earth metal salts of organic acids, primarily formates and magnesium carbonate. Vapor-phase dehydration was accomplished over alumina at about 250°C. 

Alkali Benzoate/Carbonate Vaporization. Part of the alkali content in coal is organically bound and the benzoate salts,... 

Studies regarding the reactions between sodium carbonate and potassium carbonate vapors and refractories have been limited in scope. (Many studies conducted by industry may not have been reported in the literature.) The majority have involved the examination of the degenerated features of refractories after an average service campaign. Most of the articles published have concerned the reactions between alkalies and alumino-silicate refractories utilized in glass melting and blast furnaces. 

Moon HD, Lim TH, Lee HI (1999) Chemical poisoning of Ni/MgO catalyst by alkali carbonate vapor in the steam refomring reaction of DIR-MCFC. Bull Korean Chem Soc 20 1413-1417... 

Copper does not form protective oxide fdms. Therefore, its corrosion resistance is poor against most acids and salts. Many gases-haloids, sulfurous anhydride, sulfur vapors, hydrogen sulfide, carbon dioxide, ammonium-destroy copper. However, copper is highly corrosion resistant to alkali solutions. 

The sorption of water vapor onto nonhydrating crystalline solids below RHq will depend on the polarity of the surface(s) and will be proportional to surface area. For example, water exhibits little tendency to sorb to nonpolar solids like carbon or polytetrafluorethylene (Teflon) [21], but it sorbs to a greater extent to more polar materials such as alkali halides [34-37] and organic salts like sodium salicylate [37]. Since water is only sorbed to the external surface of these substances, relatively small amounts (i.e., typically less than 1 mg/g) of water are sorbed compared with hydrates and amorphous materials that absorb water into their internal structures. 

Carbon disulfide is an extremely flammable liquid, the closed cup flash point being -22°F (-30°C). Its autoignition temperature is 90°C (194°F). Its vapors form explosive mixtures with air, within a wide range of 1.3 to 50.0% by volume in air. Reactions with certain substances can progress to explosive violence. They include finely divided metals, alkali metals, azides, fulminates, and nitrogen dioxide. 

Black crystaUine solid exists in two modifications stable black needles known as alpha form that produces ruby-red color in transmitted light, and a labile, metastable beta modification consisting of black platelets which appear brownish-red in transmitted light density of alpha form 3.86 g/cm at 0°C density of beta form 3.66 g/cm at 0°C alpha form melts at 27.3°C, vapor pressure being 28 torr at 25°C beta form melts at 13.9°C hquid iodine monochloride has bromine-hke reddish-brown color hquid density 3.10 g/mL at 29°C viscosity 1.21 centipoise at 35°C decomposes around 100°C supercools below its melting point polar solvent as a hquid it dissolves iodine, ammonium chloride and alkali metal chlorides hquid ICl also miscible with carbon tetrachloride, acetic acid and bromine the solid crystals dissolve in ethanol, ether, acetic acid and carbon disulfide solid ICl also dissolves in cone. HCl but decomposes in water or dilute HCl. 

White granular powder or cubic crystals refractive index 2.071 darkens on exposure to hght density 5.56 g/cm Moh s hardness 2.5 melts at 455°C vaporizes at 1,547°C vapor pressure 1 and 5 torr at 912 and 1,019°C insoluble in water, alcohol and dilute acids soluble in ammonia solution and concentrated sulfuric acid, alkali cyanide, ammonium carbonate also soluble in potassium bromide and sodium thiosulfate solutions. 

Light yellow hexagonal crystals or powder darkens on exposure to hght density 5.68 g/cm melts at 558°C vaporizes at 1,506°C insoluble in water, most acids and ammonium carbonate solution moderately soluble in concentrated solutions of alkali chloride, bromide, and thiosulfate readily soluble in solutions of alkali cyanides, iodides and in hot concentrated hydriodic acid. 

Colorless, mobde hquid turns yellow on standing very pungent odor refractive index 1.4437 at 20°C density 1.667 g/mL at 20°C vapors heavier than air, vapor density 4.7 (air=l) melts at -51°C bods at 69.4°C sparingly soluble in water, decomposing slowly to sulfuric and hydrochloric acids forms a hydrate S02C12 I5H2O with ice-cold water miscible with benzene, toluene, chloroform, carbon tetrachloride, and glacial acetic acid decomposed by alkalies (violent reaction occurs)... 

Silvery-white lustrous metal when pure or dark gray amorphous powder orthorhombic crystals hardness 2.3 Mohs density 6.25 g/cm melts at 452°C vaporizes at 990°C modulus of elasticity 6.0x10 psi thermal neutron absorption cross section 4.7 0.1 barns insoluble in water, carbon disulfide, and benzene also insoluble in HCl soluble in sulfuric acid, nitric acid, and aqua regia also soluble in caustic potash and in solutions of alkali metal cyanides. 

Water freezes to ice at 0°C expands by about 10% on freezing boils at 100°C vapor pressure at 0°, 20°, 50°, and 100°C are 4.6, 17.5, 92.5, and 760 torr, respectively dielectric constant 80.2 at 20°C and 76.6 at 30°C dipole moment in benzene at 25°C 1.76 critical temperature 373.99°C critical pressure 217.8 atm critical density 0.322 g/cm viscosity 0.01002 poise at 20°C surface tension 73 dynes/cm at 20°C dissolves ionic substances miscible with mineral acids, alkalies low molecular weight alcohols, aldehydes and ketones forms an azeotrope with several solvents immiscible with nonpolar solvents such as carbon tetrachloride, hexane, chloroform, benzene, toluene, and carbon disulfide. 

Scottish chemist, physicist, and physician. Professor of chemistry at Glasgow. He clearly characterized carbon dioxide ( fixed air ) as the gas which makes caustic alkalies mild, and distinguished between magnesia and lime. He discovered the latent heats of fusion and vaporization, measured the specific heats of many substances, and invented an ice calorimeter. 

Fig. 10.1.14 TEM photographs of the Fe/carbon nanotubc composites before the alkali treatment (MOCVD temperature, 400°C MOCVD period, 24 h ferrocene vapor pressure, 0.1 kPa (a) a bright-field image and (b) SAD pattern for the nanotubes from the image (a). (Front Ref. 41.)...

There are two serious problems associated with continuous tar distillation. Coal tar contains two types of components highly corrosive to ferrous metals. The ammonium salts, mainly ammonium chloride, associated with the entrained liquor remain in the tar after dehydration, tend to dissociate with the production of hydrochloric acid and cause rapid deterioration of any part of the plant in which these vapors and steam are present above 240°C. Condensers on the dehydration column and fractionation columns are also attacked. This form of corrosion is controlled by the addition of alkali (10% sodium carbonate solution or 40% caustic soda) to the cmde tar in an amount equivalent to the fixed ammonia content. 

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