Study On Preparation Of NO And Removal Of Impurities

Nitric oxide (NO) is a new type of functional material, which is widely used in chemical synthesis, semiconductor, aerospace and other industries, especially in the fields of medical and life sciences. It was found that NO was involved in almost all of the functional activities of the organism. Studies have shown that it is effective for treating disorders such as high blood pressure, diabetes, cardiovascular disease, cancer and other diseases by regulating the metabolism of human NO. NO products usually contain some harmful impurities, which will seriously affect the application of NO in the above new fields. Therefore, these impurities need to be removed through the appropriate treatment.According to the literature, there are many methods of preparation of NO. In this paper, NO product was obtained by the reaction of dilute sulfuric acid and sodium nitrite. High purity NO product was obtained through the primary purification and deep purification. The related removal process and the specific technological parameters are discussed in detail. Conclusions are drawn as follows:1. NO gas was prepared by redox reaction with a certain concentration of dilute sulfuric acid and sodium nitrite. The yield of this method is high and the impurities are few. The purity of 99% NO product can be obtained after the initial purification treatment.2. The main impurities in NO gas are H2O, CO2, N2O, NO2, N2, particulate matter, etc. The content of impurities was determined by the dew-point meter, gas chromatograph, gas detector and other methods.3. Ideal purity of product was got through silica gel adsorption and molecular sieve adsorption at room temperature, activated carbon adsorption at low temperature and repeated freezing vacuum treatment of crude product.4. The effect of pressure on the removal of impurities in NO gas at room temperature was studied. The results showed that the contents of the related impurities in NO decreased significantly with the increase of system pressure.5. The effect of temperature and pressure on the removal of impurities in NO gas was studied. The results show that the adsorption effect of active carbon on NO is obviously improved with the decrease of temperature. However, when the temperature is lower than-100?, it is easy to cause blockage of active carbon adsorber. Increased pressure is beneficial to reduce the impurity content in NO.6. The N2 in NO can be effectively removed by cryogenic vacuum treatment before the vacuum treatment at room temperature. The metal mesh filter can effectively reduce the solids.