Study On Process Of Oxidation Of Propylene

Alkene oxidation process is very important in petrochemical industry. Through alkene oxidation, plenty of very useful organic chemicals can be produced. Taking propylene as feed, through selectivity oxidation, we can get propylene epoxide, acrolein, acroleic acid, acetone and other useful products. This paper mainly studies on the process of producing propylene epoxide by propylene selectivity oxidation.Propylene epoxide is an important organic chemical material, the yield of which is only under polypropylene and acrylonitrile in propylene derivants. It is usually used to produce polyether polybasic alcohol further to get polyurethane. Commercial propylene epoxide production almost adopts chlorohydrin method and co-oxidation method. The former has mature technology, good selectivity, high yield, low investment cost, but in production process it can bring lots of sewage with chlorine and waste residue, corrode devices and pollute environment seriously; the latter has little pollution and corrosion but has complex methodology, long flow path, high demand of device, high investment cost and can be restricted by the market of joint products. Because the present technologies exist these disadvantages, new production engineering of propylene epoxide is being actively developed.The technology of hydrogen peroxide oxidizing propylene has some advantages such as simple process, moderate environment and low reaction temperature but it also exists some problems such as hydrogen peroxide costs too much, security of storing and transport is bad and the propylene epoxide is easy to open loop. Because the technology of ethylene and oxygen epoxidation to produce propylene epoxide has been industrialized, researchers pay close attention to the technology of propylene and oxygen directly oxidize to produce propylene epoxide which has become focus of research.This technology has simple process, low production cost and moderate environment, but the whole effect is not very good, the yield of propylene epoxide is little.This paper develops a new technology which has not been reported all over the world. Propylene is oxidized to get propylene epoxide taking oxygen as oxidant, nitric oxide as oxygen carrier, of which the process is simple, energy waste is little and production cost is low, but at present the selectivity of propylene epoxide is not good enough, which should be further researched. This paper compares propylene oxidation technology under two conditions—with catalyst and without catalyst, and finally comes at optimal technological conditions: with catalyst MoO₃/SiO₂, the loading of MoO₃ is 7%, the volume ratio of reactant gases is C₃H₆:O₂:NO=8:2:3, 30% of N₂, the airspeed of reactant gas is 7500h^-1, reaction temperature is 80℃, condensation temperature is 20℃. Under these conditions, the selectivity of propylene epoxide is 9.68% and of acrolein is 20.48%, the percent conversion of propylene is 17.61%, the unit weight of liquid is 334.62g.