CATALYST BASED ON PALLADIUM(II), COPPER(II) COMPOUNDS AND THERMALLY-MODIFIED TRIPOLI FOR THE PREPARATION OF RESPIRATORY REMEDIES FROM CARBON MONOXIDE IN EMERGENCY SITUATIONS

Abstract

Nowadays, the number of emergency situations related to fires is quite high. The high percentage of human deaths is mainly due to poisoning by gaseous toxic substances including carbon monoxide. The most problematic issue is the development or application of existing catalysts in means of individual protection of human respiratory organs – respirators, gas masks, self-rescuers. The compositions based on thermally modified tripoli obtained by the method of impregnation of the carrier by moisture content with compounds of copper(II), palladium(II) and potassium bromide were investigated. According to X-ray phase analysis, it was established that thermally modified tripoli is a polyphase crystalline mineral containing the following main phases: a-quartz, a-tridymite, b-cristobalite, a-cristobalite. The influence of the initial concentration of CO, which does not exceed 15 MPC, on the kinetic and stoichiometric parameters of the reaction varied in the range from 100 to 300 mg/m3. It was noted that the reaction rate in the stationary mode (Wst) is directly proportional to the increase in the initial concentration of carbon monoxide in the gas phase. The values of the constant kI and the degree of CO conversion (ηst) do not depend on CinCO, which also confirms the first order of CO concentration. Particular attention is paid to the aspects of ensuring protection against carbon monoxide when its concentration exceeds 15 MPC. Usually, special equipment, such as filtering self-rescuers, is used to clean the air from carbon monoxide at concentrations from 1000 to 6500 mg/m3. The catalyst developed by us is intended for use in lightweight personal respiratory protective equipment (RPE) at concentrations not exceeding 15 MPC. Therefore, there was an interest in researching the possibilities of using this catalyst in the self-saving filter system. The concentration of carbon monoxide in the gas-air mixture was varied from 400 to 2500 mg/m3 in the presence of the К2PdCl4-Cu(NO3)2-КBr/300-Tr(K) system. It was established that Wst increases in direct proportion with an increase in the gas-air mixture up to 1250 mg/m3, which indicates the first order of the reaction according to carbon monoxide. It was found that at CinCO = 1000 mg/m3 only under the condition τ´ = 1.13 s (mk = 10 g) the К2PdCl4-Cu(NO3)2-KBr/Tr catalyst provides air purification below the breakthrough CO concentration (CfCO = 200 mg/m3). Experiments on the influence of SO2 on the activity of carbon monoxide oxidation catalysts have shown that they lose their activity, so in air purification systems from CO, it is necessary to provide for the stage of capturing sulfur dioxide.