Destructive oxidation of ethanol in the corona discharge reactor

Abstract

Destructive oxidation of ethanol in the corona discharge reactor The results of investigation of ethanol destructive oxidation (model aliphatic alcohol) in a corona discharge reactor are presented. The process was performed at the temperature of 303 K in the corona discharge generator - the reactor system manufactured in our laboratory. The process temperature was kept constant by cooling down the reactor with a stream of air. The measurements were carried out using the following process parameters: the inlet ethanol concentration in the stream of gases in the range of 0.0028 to 0.132 mol/m3 (0.128 ÷ 6.086 g/m3), the gas flow velocity in the range of 0.15-0.33 m3/h (space velocity in the range of 1220 ÷ 2680 m3/(m3 R ·h)) and the power supply to the reactor ranged from 1.6 to 86.4 W. The active volume of the reactor was 1.23·10-4 m3. The phenomenological method was applied for the description of the process. It was based on the assumptions that the reaction rate can be described by the first order equation in relation to the ethanol concentration and the design equation of flow tubular reactor can be applied for the description of corona reactor. The usefulness of this model was estimated using statistical methods for the analysis of the experimental results. The Statistica 6.0 software was used for this application. The first stage of this analysis showed the dependencies between the considered variables, whereas the second stage was to find the equations describing the influence of the selected process parameters on the rate of ethanol destruction. The parameters of A and B of apparent constant rate equation given in the form of Z = A·exp(-B/P) were also determined. The results of the investigations indicated that the applied corona discharge generator - reactor system assures a high efficiency of purification of the air and industrial waste gases contaminated by ethanol. The ethanol destruction degree of αi = 0.9 was obtained at the power supply to the reactor amounting to 650 kW/m3 R per unit of its active volume. The final products of the reaction were only the harmless carbon dioxide and water vapour. It has been stated that the rate of the destructive oxidation of ethanol reaction is well described by the first order equation in relation to the ethanol concentration. Under isothermal conditions, the reaction rate also depends on the power supply to the reactor. This dependence is well described by the empirical equation Z = 3,233·exp(-82,598/P). The obtained results also indicated that the method of destructive oxidation of ethanol in the corona discharge reactor can be useful for the removal of ethanol and probably other aliphatic alcohols from different gases. The described method of calculation of the real rate of the process can be successfully used in the design of corona discharge reactors applied for such processes.