Carbonic Acid Gas

Chemical Designations - Synonyms Carbonic Acid Gas Carbonic Anhydride Chemical Formula CO2. 

A still more intense degree of cold may bo attained by the rapid evaporation of liquids, such as bisulphide of carbon, ether, protoxide of nitrogen, and solid carbonic acid gas. By employing a bath of carbonic acid and ether in vacua, Faraday reduced the temperature... 

If carbon is present in greater proportion, it is taken up by the carbonic acid gas, which thereby passes intp the state of carbonic oxide—... 

The Orifice is effectually closed by the internal pressure of thfl Carbonic Acid Gas against the glass ball, which presses hard up against the ring in the neck. 

Nitrogen gas is fed at a fixed flow rate. After confirming that the flow in the column has a steady state and that the carbonic acid gas in the water is desorbed, the carbonic acid gas as the tracer is fed stepwise at the same flow rate as the fixed flow rate of nitrogen gas by changing the valve. The change in concentration of the tracer with time in each region is measured by making use of the electrode conductivity probe after the tracer gas is fed, and the mixedness M defined by Eq. (2.18) is calculated. 

Seidel, R. O., Experience in the Operation of Activated Hot Potassium Carbonate Acid Gas Removal Plants (U.8.). Seminar on Raising Productivity in Fertilizer Plante, Baghdad, Iraq, March 23-26, 1978. 

This behavior permits the discarding of the earthenware cylinder. It suffices to envelop the cathodes with parchment paper, whereby the resistance and the consumption of electrical energy is considerably diminished. The diffusion of the free alkali hydroxide away from the cathode necessitates the continuous introduction of carbonic-acid gas, because caustic alkali prevents the formation of iodoform, while carbonate promotes it. When using the covered cathodes, 20 g. calcined soda, 20 g. potassium iodide, and 50 cc. alcohol in 200 cc. water are electrolyzed at a temperature of 50°-70° a current of carbonic-acid gas being conducted into the solution between anode and... 

Potassium Trichlonnethyl-Sulphate.—This compound, electrolyzed by Bunge,6 gave hydrogen and alkali at the negative pole and at the positive pole oxygen, carbonic-acid gas, chlorine, sulphuric acid, and perchloric acid. 

Carbonic Acid.—Carbonic acid deserves mention here because it can be converted electrolytically into formic acid. Royer 6 observed its formation at zinc and zinc-amalgam electrodes in the electrical reduction of carbonic acid dissolved in water, a current of the gas being conducted through the latter during electrolysis. Klobukow 7 was likewise able to prove the presence of formic acid in water which was electrolyzed and through which a current of carbonic-acid gas was passed. 

The potassium salt is precipitated as a blue powder. It has not been possible to isolate other salts and free percarbonic acid. The experiments of Saber,1 however, indicate that the free acid may occur perhaps intermediately. He proved the presence of active oxygen in a solution of potassium bicarbonate through which was passed a continuous current of carbonic-acid gas. 

The acid salt is very energetically decomposed, becoming first red and then brown. At the anode carbonic-acid gas, carbon monoxide, oxygen, and nitrogen escape (Bourgoin1). 

Ethyl Alcohol.—In an atmosphere of ethyl-alcohol vapors, M. Quet5 and Perrot 6 obtained, besides some carbon, a substance which exploded on being heated, the chemical nature of which they were unable to determine. The liquid became acid but Perrot found that no water was formed in the decomposition of the alcohol he was also unable to prove the presence of carbonic acid gas. Melly 7 and Lommel8 made similar experiments, the latter employed a Holtz machine. The gas escaping in the decomposition of the alcohol probably contains acetylene and ethylene. 

A mixed gas of 60-75 percent C02 derived from mixing the 40 percent C02 from the kilns and the 90 percent C02 from the calcinations of bicarbonate, is fed to the bottom of these crystallizing units. Absorption of C02 in the highly alkaline ammoniated brine results in crystallization of crude sodium bicarbonate. Because of the heat evolved in the absorption and neutralization of the carbonic acid gas and from crystallization of the sodium bicarbonate, the temperature of the liquor in the column rises from 38°C to a maximum of about 62-64°C. In normal operation, the temperature of the discharge slurry is maintained at about 27°C by automatic adjustment of the water flow through the cooling tubes. A tower such as that shown in Fig. 26.2 has a capacity for producing 50 tons per day of finished soda. 

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