Carbon dioxide with potassium carbonate

Catacarb process An extraction process used to remove carbon dioxide from process gases by scrubbing the hot gases with potassium carbonate solution containing additives which increase the hydration rate of the gas in the solution. The Vetrocoke process is similar. See Benfield process. 

Potassium Carbonate. Except for small amounts produced by obsolete processes, eg, the leaching of wood ashes and the Engel-Precht process, potassium carbonate is produced by the carbonation, ie, via reaction with carbon dioxide, of potassium hydroxide. Potassium carbonate is available commercially as a concentrated solution containing ca 47 wt % K CO or in granular crystalline form containing 99.5 wt % K CO. Impurities are small amounts of sodium and chloride plus trace amounts (<2 ppm) of heavy metals such as lead. Heavy metals are a concern because potassium carbonate is used in the production of chocolate intended for human consumption. 

Amino-2-hydroxybenzoic acid is manufactured by carboxylation of 3-amiaophenol under pressure with ammonium carbonate at 110 °C (182) or with potassium bicarbonate and carbon dioxide at 85—90°C (183) with subsequent acidification. 

The analytical chemistry of titanium has been reviewed (179—181). Titanium ores can be dissolved by fusion with potassium pyrosulfate, followed by dissolution of the cooled melt in dilute sulfuric acid. For some ores, even if all of the titanium is dissolved, a small amount of residue may still remain. If a hiU analysis is required, the residue may be treated by moistening with sulfuric and hydrofluoric acids and evaporating, to remove siUca, and then fused in a sodium carbonate—borate mixture. Alternatively, fusion in sodium carbonate—borate mixture can be used for ores and a boiling mixture of concentrated sulfuric acid and ammonium sulfate for titanium dioxide pigments. For trace-element deterrninations, the preferred method is dissolution in a mixture of hydrofluoric and hydrochloric acids. 

Methods of Purification. Although carbon dioxide produced and recovered by the methods outlined above has a high purity, it may contain traces of hydrogen sulfide and sulfur dioxide, which cause a slight odor or taste. The fermentation gas recovery processes include a purification stage, but carbon dioxide recovered by other methods must be further purified before it is acceptable for beverage, dry ice, or other uses. The most commonly used purification methods are treatments with potassium permanganate, potassium dichromate, or active carbon. 

Potassium Permanganate. Probably the most widely used process for removing traces of hydrogen sulfide from carbon dioxide is to scmb the gas with an aqueous solution saturated with potassium permanganate [7722-64-7]. Sodium carbonate is added to the solution as buffer. The reaction is as foUows ... 

Terephthalic acid has been obtained from a great many /)-disubstituted derivatives of benzene or cyclohexane by oxidation with permanganate, chromic acid, or nitric acid. The following routes appear to have preparative value from />-toluic acid, />-methylacetophenone,2 or dihydro-/)-tolualdehyde by oxidation with permanganate from f>-cymene by oxidation with sodium dichromate and sulfuric acid from />-dibromobenzene or from /i-chloro- or -bromobenzoic acid by heating at 250° with potassium and cuprous cyanides and from />-dibromo-benzene, butyllithium, and carbon dioxide. ... 

Cathylates are stable to oxidation with potassium chromate in acetic acid and with A-bromoacetamide, acetylation and formylation with 85 % formic acid at room temperature. They are cleaved by bases to give the parent alcohol, carbon dioxide and ethanol. 

In a German patent issued in 1929, Bergs described a synthesis of some 5-substituted hydantoins by treatment of aldehydes or ketones (1) with potassium cyanide, ammonium carbonate, and carbon dioxide under several atmospheres of pressure at 80°C. In 1934, Bucherer et al. isolated a hydantoin derivative as a by-product in their preparation of cyanohydrin from cyclohexanone. They subsequently discovered that hydantoins could also be formed from the reaction of cyanohydrins (e.g. 3) and ammonium carbonate at room temperature or 60-70°C either in water or in benzene. The use of carbon dioxide under pressure was not necessary for the reaction to take place. Bucherer and Lieb later found that the reaction proceeded in 50% aqueous ethanol in excellent yields for ketones and good yields for aldehydes. ... 

Procedure. The arsenic must be in the arsenic (III) state this may be secured by first distilling in an all-glass apparatus with concentrated hydrochloric acid and hydrazinium sulphate, preferably in a stream of carbon dioxide or nitrogen. Another method consists in reducing the arsenate (obtained by the wet oxidation of a sample) with potassium iodide and tin(II) chloride the acid concentration of the solution after dilution to 100 mL must not exceed 0.2-0.5M 1 mL of 50 per cent potassium iodide solution and 1 mL of a 40 per cent solution of tin(II) chloride in concentrated hydrochloric acid are added, and the mixture heated to boiling. 

Sulphur as well as phosphorus gives highly violent reactions when they are heated with potassium. With carbon disulphide, potassium creates a mixture, which detonates on impact. The same happens by heating. With sulphur dioxide, potassium in the molten state combusts. Finally, the potassium/sulphuric acid mixture gives rise to detonations. 

The same goes for peroxides and superoxides. Thus, tin powdered which was in contact with sodium peroxide in a carbon dioxide atmosphere in the presence of water traces glowed before combusting. With potassium superoxide there is an immediate incandescence of the mixture. 

Interaction is exothermic, and if air is present, incandescence may occur with freshly prepared granular material. Admixture with oxygen causes a violent explosion [1], Soda-lime, used to absorb hydrogen sulfide, will subsequently react with atmospheric oxygen and especially carbon dioxide (from the solid coolant) with a sufficient exotherm in contact with moist paper wipes (in a laboratory waste bin) to cause ignition [2], Spent material should be saturated with water before separate disposal. Mixture analogous to soda-lime, such as barium hydroxide with potassium or sodium hydroxides, also behave similarly [1],... 

Mixtures of potassium and solid carbon dioxide are shock-sensitive and explode violently on impact, and carbon monoxide readily reacts to form explosive carbonylpotassium (potassium benzenehexoxide) [1]. Dichlorine oxide explodes on contact with potassium [2], Potassium ignites in dinitrogen tetraoxide or dinitrogen pentaoxide at ambient temperature and incandesces when warmed with nitrogen oxide or phosphorus(V) oxide [3], At — 50°C, potassium and carbon monoxide react to give dicarbonylpotassium, which explodes in contact with air or water, or at 100°C. At 150°C, the product is a trimer of this, potassium benzenehexoxide. The just-molten metal ignites in sulfur dioxide [4],... 

Tetraphosphorus trisulfide (P4S3) which is also called phosphorus sesquisulfide, can be obtained by heating a stoichiometric mixture of phosphorus and sulfur at 180 °C in an inert atmosphere. The compound (m.p. 174 °C) is soluble in toluene, carbon disulfide, and benzene, and it is used with potassium chlorate, sulfur, and lead dioxide in matches. 

Hannaker and Buchanan [82] used a method based on wet oxidation with potassium persulfate [83] for the determination of dissolved organic content in concentrated brines following the removal of inorganic carbonates with phosphoric acid. The method involves wet oxidation with potassium persulfate at 130 °C followed by a hot copper oxidation and gravimetric measurement of the carbon dioxide produced. The technique overcomes difficulties of calibration curvature, catalytic clogging, and instrument fouling often encountered with instrumental methods. 

An alternative method for the determination of particulate organic carbon in marine sediments is based on oxidation with potassium persulfate followed by measurement of carbon dioxide by a Carlo Erba non-dispersive infrared analyser [152,153]. This procedure has been applied to estuarine and high-carbonate oceanic sediments, and results compared with those obtained by a high-temperature combustion method. 

MAGSORB A process for removing caibon dioxide from hot gas streams by reversible absorption on magnesium oxide modified with potassium carbonate. Developed by the Institute of Gas Technology, Chicago, for fuel gas derived from coal. 

Several fluoro analogs of ketoses have been reported 1,6-dideoxy-1,6-difluoro-D-fructose was readily obtained from 2,3-O-isopropyli-dene-l,6-di-0-p-tolylsulfonyl-)3-D-fructofuranose by treatment with potassium fluoride in 1,2-ethanediol under a stream of carbon dioxide.96 Surprisingly, although the 6-sulfonyloxy group would be expected to be more reactive than the 1-sulfonyloxy group,97-99 no selectivity was observed. The failure to obtain 1-deoxy-l-fluoro-D-fructopyranose96 from 2,3 4,5-di-0-isopropylidene-l-0-(methylsulfonyl) (or p-nitro-phenylsulfonyl)-/3-D-fructopyranose or phenyl 3,4,5-tri-O-acetyl-l-O-(methylsulfonyl)-/3-D-fructopyranoside by treatment with potassium or sodium fluoride in 1,2-ethanediol, N,N-dimethylformamide, or form-amide at elevated temperatures may be attributed to the fact that nu-... 

Various other workers have discussed the determination of organic carbon in river sediments. [18, 23, 24] Suzuki et al. [23] applied wet combustion to the sediment and absorbed the carbon dioxide produced in sodium hydroxide solution, prior to determination in a TOC analyser. Whitfield and McKinley [24] recommended that samples for determination of organic carbon should be filtered immediately and analysed as soon as possible. Charles and Simmons [18] stated that greater accuracy is obtained with dry microcombustion techniques and that wet oxidations with potassium... 

Phenylacetylene has been prepared by the elimination of carbon dioxide from pbenylpropiolic acid by means of phenol1 or aniline 2 or by heating with barium hydroxide 3 from styrene dibromide, by heating with potassium hydroxide in alcohol 4 by heating /3-bromo or chloro styrene with sodium ethylate or potassium hydroxide in alcohol 5 by passing the vapors of a-dichloroethylbenzene over hot soda lime 6 by the action of alcoholic potassium hydroxide on dibenzal-acetone tetra-... 

Rubidium also may be recovered by the chlorostannate method. In this method the alkali metal carbonate solution obtained from the mixed alum is treated with carbon dioxide. Most potassium is precipitated as bicarbonate, KHCO3. Addition of hydrochloric acid converts the carbonates to chlorides. The chlorides are converted to chlorostannates by carefully adding stoichiometric quantities of stannic chloride at pH just below 7 ... 

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