Preparation of Carbon Dioxide

Carbon Dioxide. Acquaint yourself with the design of a Kipp gas generator (Fig. 33) and charge it for the preparation of carbon dioxide. Remove stopper with cock 1 and charge middle sphere 2 up... 

This reaction is used in the laboratory preparation of carbon dioxide (p. 214). It is also used as a test for a carbonate because the reaction produces carbon dioxide which causes effervescence and if bubbled through limewater turns it chalky white. 

Laboratory preparation of carbon dioxide and its properties (Figure 13.16, p. 214). 

Preparation of carbon dioxide. The commercial production of carbon dioxide by the reaction between steam and either methane or hot car-... 

Aim To get pupils to fit up the apparatus for the preparation of carbon dioxide in the laboratory, prepare the gas and study its chief physical and chemical properties. 

Discussion The preparation of ammonia from ammonium chloride and calcium hydroxide resembles the preparation of carbon dioxide from an acid and a carbonate in that a double decomposition is immediately followed by the spontaneous breaking up of one of the products into water and a gas. In both cases also the secondary reaction is reversible and with ammonia this reversal, together with the great solubility of ammonia gas itself, is so marked as to require the use of solid material instead of solutions, in order to reduce as much as possible the amount of water present. 

Compston W, Epstein S (1958) A method for the preparation of carbon dioxide from water vapor for oxygen isotopic analysis. EOS Trans Am Geophys Union 39 511 Craig H, Horn B (1968) Relationships of deuterium, oxygen-18, and chlorinity in the formation of sea ice. EOS Trans Am Geophys Union 216... 

Sofer, Z. (1980) Preparation of carbon dioxide for stable isotope analysis of petroleum fractions. Analyt. Chem., 52, 1389-91. 

It seems appropriate therefore to consider briefly the preparation of hydrogen, carbon dioxide and nitrogen required for the isotopic analysis of H, and content respectively. The preparation of carbon dioxide and sulphur dioxide for analysis of and content will not be considered in detail as these isotopes have as yet very limited application in a clinical context. 

If the reaction mixture used in the above preparation of formic acid is heated to 190-200°, the glyceryl monoformate which has escaped hydrolysis undergoes decomposition, with the loss of carbon dioxide and water, and the... 

Prepare a mixture of 30 ml, of aniline, 8 g. of o-chloro-benzoic acid, 8 g. of anhydrous potassium carbonate and 0 4 g. of copper oxide in a 500 ml. round-bottomed flask fitted with an air-condenser, and then boil the mixture under reflux for 1 5 hours the mixture tends to foam during the earlier part of the heating owing to the evolution of carbon dioxide, and hence the large flask is used. When the heating has been completed, fit the flask with a steam-distillation head, and stcam-distil the crude product until all the excess of aniline has been removed. The residual solution now contains the potassium. V-phenylanthrani-late add ca. 2 g. of animal charcoal to this solution, boil for about 5 minutes, and filter hot. Add dilute hydrochloric acid (1 1 by volume) to the filtrate until no further precipitation occurs, and then cool in ice-water with stirring. Filter otT the. V-phcnylanthranilic acid at the pump, wash with water, drain and dry. Yield, 9-9 5 g. I he acid may be recrystallised from aqueous ethanol, or methylated spirit, with addition of charcoal if necessary, and is obtained as colourless crystals, m.p. 185-186°. 

In the flask was placed a solution of 50 g of carbon dioxide in 250 ml of dry THF, made by introducing the gas from a cylinder into THF, cooled at about -90°C (liquid nitrogen bath). The gas inlet was removed and through the neck of the reaction flask was poured a cold solution (-70°C) of 0.40 mol of allenyl1ithiurn in 280 ml of hexane and 280 ml of THF (prepared as described in Chapter II,... 

New Synthesis. Many attempts have been made to synthesize oxaUc acid by electrochemical reduction of carbon dioxide in either aqueous or nonaqueous electrolytes (53—57). For instance, oxaUc acid is prepared from CO2 as its Zn salt in an undivided ceU with Zn anodes and stainless steel cathodes ia acetonitrile containing (C4H2)4NC104 and current efficiency of >90% (53). Micropilot experiments and a process design were also made. 

Synthetic chemical approaches to the preparation of carbon-14 labeled materials iavolve a number of basic building blocks prepared from barium [ CJ-carbonate (2). These are carbon [ C]-dioxide [ CJ-acetjlene [U— C]-ben2ene, where U = uniformly labeled [1- and 2- C]-sodium acetate, [ C]-methyl iodide, [ C]-methanol, sodium [ C]-cyanide, and [ CJ-urea. Many compHcated radiotracers are synthesized from these materials. Some examples are [l- C]-8,ll,14-eicosatrienoic acid [3435-80-1] inoxn. [ CJ-carbon dioxide, [ting-U— C]-phenyhsothiocyanate [77590-93-3] ftom [ " CJ-acetjlene, [7- " C]-norepinephrine [18155-53-8] from [l- " C]-acetic acid, [4- " C]-cholesterol [1976-77-8] from [ " CJ-methyl iodide, [l- " C]-glucose [4005-41-8] from sodium [ " C]-cyanide, and [2- " C]-uracil [626-07-3] [27017-27-2] from [ " C]-urea. All syntheses of the basic radioactive building blocks have been described (4). 

Early Synthesis. Reported by Kolbe in 1859, the synthetic route for preparing the acid was by treating phenol with carbon dioxide in the presence of metallic sodium (6). During this early period, the only practical route for large quantities of sahcyhc acid was the saponification of methyl sahcylate obtained from the leaves of wintergreen or the bark of sweet bitch. The first suitable commercial synthetic process was introduced by Kolbe 15 years later in 1874 and is the route most commonly used in the 1990s. In this process, dry sodium phenate reacts with carbon dioxide under pressure at elevated (180—200°C) temperature (7). There were limitations, however not only was the reaction reversible, but the best possible yield of sahcyhc acid was 50%. An improvement by Schmitt was the control of temperature, and the separation of the reaction into two parts. At lower (120—140°C) temperatures and under pressures of 500—700 kPa (5—7 atm), the absorption of carbon dioxide forms the intermediate phenyl carbonate almost quantitatively (8,9). The sodium phenyl carbonate rearranges predominately to the ortho-isomer. sodium sahcylate (eq. 8). 

Sodium Aluminum Sulfate (SAS). Sodium aluminum sulfate is a dehydrated double salt of aluminum and sodium sulfate. It does not react with baking soda in cold, but in the heat of oven 1 mol of SAS produces 6 mol of carbon dioxide from reacting with baking soda. Historically, SAS was one of the first materials used to Hberate carbon dioxide from baking soda. Today its primary use is in household baking powder production. It is used either alone or in combination with MCP. SAS is not recommended for use in prepared mixes due to its lack of compatibiHty with other ingredients in a mix. 

Available data on the thermodynamic and transport properties of carbon dioxide have been reviewed and tables compiled giving specific volume, enthalpy, and entropy values for carbon dioxide at temperatures from 255 K to 1088 K and at pressures from atmospheric to 27,600 kPa (4,000 psia). Diagrams of compressibiHty factor, specific heat at constant pressure, specific heat at constant volume, specific heat ratio, velocity of sound in carbon dioxide, viscosity, and thermal conductivity have also been prepared (5). 

Ethylene carbonate (l,3-dioxolan-2-one) is commercially prepared from ethylene oxide by the addition of carbon dioxide to ethylene oxide with either ammonium or alkaU metal salts as catalysts (87) ... 

Ethylene Oxide Catalysts. Of all the factors that influence the utihty of the direct oxidation process for ethylene oxide, the catalyst used is of the greatest importance. It is for this reason that catalyst preparation and research have been considerable since the reaction was discovered. There are four basic components in commercial ethylene oxide catalysts the active catalyst metal the bulk support catalyst promoters that increase selectivity and/or activity and improve catalyst life and inhibitors or anticatalysts that suppress the formation of carbon dioxide and water without appreciably reducing the rate of formation of ethylene oxide (105). 

Hydroxybenzoic acid has been prepared by heating potassium phenoxide in a stream of carbon dioxide or with carbon tetrachloride, and by heating jfr-cresol with alkalies and various metallic oxides. The procedure described above is similar to one which appears in the early literature ... 

The procedure for preparing 6-hydroxynicotinic acid is also based on a method described by von Pechmann. 6-Hydroxynico-tinic acid has also been prepared by decarboxylation of 6-hy-droxy-2,3-pyridinedicarboxylic acid by heating 6-hydra-zinonicotinic acid or its hydrazide with hydrochloric acid by the action of carbon dioxide on the sodium salt of a-pyridone at 180-200 and 20 atmospheres by heating the nitrile of 6-chlo-ronicotinic acid with alcoholic sodium hydroxide or hydrochloric acid from 6-aminonicotinic acid and by the prolonged action of concentrated ammonium hydroxide on methyl cou-malate. ... 

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