Property and Preparation of n-Butyl Nitrate

The conventional preparation method of n-butyl nitrate is to nitrate n-butanol by the mixed acid of nitric acid and sulfuric acid. However, the yield is very low by this 

As shown in Fig. 5.7, the differences between the preparation of -butyl nitrate and the other monobasic alcohol nitrates are evident (1) The nitration process for the other nitrate esters, such as methyl nitrate, is the continuous nitration-distillation method, while for n-butyl nitrate, the process is the reflux and water segregator method (2) In the washing process, n-butyl nitrate is washed by saturated sodium chloride solution because its density is close to that of water. 

The key device in the preparation of n-butyl nitrate is the water segregator, which is seldom used in chemistiy. The segregator is particularly designed in application of the preparation of n-butyl nitrate based on the requirements and working condition. The production facilities of n-butyl nitrate are shown in Fig. 5.8. 

The volume of the nitration reactor is about 110 L equipped with an explosion proof motor, a cycloidal reducer, mechanical seals, an anchor agitator, a temperature sensor, a pressure gauge, three feeding holes with different size, a segregator with a glass mirror, 1,000 mm condenser, and a jacket of heat transfer oil. The system also includes a temperature controller, an agitation controller, and a washing vessel. By application of the production unit, the yield of n-butyl nitrate is up to 95.7 % with the purity of 98.88 %. 

The composition of nitration solution is 60 wt% HNO3, 30 wt% H2O, and 10 wt% protective agent. The protective agent is composed of 80 wt% urea and 20 wt% ammonium nitrate. The nitration solution in a reactor is heated to 82 °C, and then both n-pentanol and 15 % urea aqueous solution are slowly added into the reactor. If the addition rate of n-pentanol is too fast, the reaction solution would be overflown. When the temperature reaches 95 °C, water in the reaction system will be segregated. The temperature of the oil bath is set at around 160 °C and the 

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