Laboratory Setup for Producing Carbon Monoxide
Abstract Generated abstract
This paper describes a compact laboratory installation for producing carbon monoxide in quantities suitable for synthesis work, addressing the cost and purity limitations of common acid decomposition methods. The proposed setup generates carbon monoxide by passing carbon dioxide through electrically heated carbonaceous material at 1200 to 1300°C, then removes residual carbon dioxide using an alkali purification column with indicator and control wash bottles. The author presents the operating scheme, startup procedure, safety and flow regulation elements, and notes that a bench scale apparatus occupying about 0.5 m² can produce up to 250 liters of carbon monoxide per hour or more.
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LABORATORY SETUP FOR PRODUCING CARBON MONOXIDE
S. I. Smolyaninov
(Presented by Prof. Dr. of Technical Sciences I. V. Gebler)
Carbon monoxide plays a major role in many organic syntheses. It acquires special importance in syntheses from mixtures of carbon monoxide, hydrogen, or water vapor. At the present time, the results achieved in the field of synthesis from carbon monoxide make it possible to believe that motor fuel and organic products can be obtained on an industrial scale not only by processing high-molecular-weight products, but also by synthesis from gases containing carbon monoxide [1].
Obtaining sufficiently large quantities of carbon monoxide under laboratory conditions is associated with certain difficulties. Here this gas is usually obtained by decomposing formic acid with sulfuric or phosphoric acids [2]. A number of other similar methods have limited application, since they give a contaminated gas. But even in the first method, a good gas is obtained only when the purest acid is used; moreover, it is associated with a considerable consumption of relatively expensive reagents.
In the laboratory, carbon monoxide can also be obtained by the reaction of carbon dioxide with incandescent carbon. This method is attractive above all because of the cheapness and availability of the starting materials.
Its disadvantage is the difficulty of attaining the high temperatures needed to ensure high efficiency of the process. These difficulties are overcome in the simple and convenient electric gas generator we have used [3]. In principle, the generator consists of two electrodes, between which a layer of electrically conductive carbonaceous material (charcoal, coke, etc.) is placed, heated to the required temperature by the electric current passing through it.
The general scheme of the setup for producing carbon monoxide is shown in Fig. 1.
Carbon dioxide from cylinder 1 with reducing valve 2 enters electric gas generator 3. Heating of the generator is regulated by autotransformer 4. The temperature is monitored with pyrometer 5. The carbon monoxide formed, together with unreacted carbon dioxide, is fed into the purification system by rotary gas blower 7. The rate of suction is regulated by means of a small wet bell-type gas holder 6, the motion of whose bell is mechanically connected with bypass 8 of gas blower 7. Before the purification system a water hydraulic seal 9 is installed, operating as a safety device. Purification of the gas from residual carbon dioxide is carried out with a 20–25-percent solution of caustic soda in a high-capacity column with automatic irrigation [4]. The gas then passes through flowmeter 11 and indicator wash bottle 12. This bottle is filled with a slightly alkalized weak solution of alizarin yellow and serves to monitor the degree of exhaustion of the circulating alkali solution in column 10. When carbon dioxide breaks through, the orange color of the solution changes to straw-yellow. As the alkali in column 10 becomes exhausted, both it and the indicator solution may be replaced with fresh ones.
on the line. To completely prevent carbon dioxide from passing through, a control bottle 13 with an alkali solution is installed. The purified gas is collected in gas holder 14, from which it is fed to the synthesis as required.
Before starting operation, the gas generator is charged with calcined charcoal (fraction 1–7 mm), and the entire system is purged with carbon dioxide. Then, in a weak stream of carbon dioxide, the generator is brought to the normal temperature regime (1200–1300°C), and the residual carbon dioxide gas is displaced by carbon monoxide, which is then directed to the gas holder.
Fig. 1. Diagram of an installation for producing carbon monoxide.
Such an installation, with very small dimensions (the laboratory bench area occupied by it is 0.5 m²), can be constructed for a capacity of up to 250 liters of carbon monoxide per hour and higher.
LITERATURE
- RAPOPORT I. B. Artificial Liquid Fuel. Gostoptekhizdat, 1955.
- SHMIDT Yu. Carbon Monoxide, Its Significance and Application in Technical Chemistry. ONTI, 1936.
- SMOLYANINOV S. I. Bulletin of Inventions, No. 7, p. 26, 1956.
- CHMUTOV K. V. Technique of Physicochemical Investigation. Goskhimizdat, 1948.