丙烯和氧等离子体直接气相合成环氧丙烷

在室温和大气压下，在针板式反应器中，通过脉冲电晕放电等离子体对分子氧和丙烯直接合成环氧丙烷的活化作用，考察了放电电极间距、电晕放电脉冲电压以及电晕放电重复频率参数对丙烯转化率、环氧丙烷产率和其选择性的影响，反应物及各产物通过在线色谱法进行分析．实验结果表明，在室温和大气压下，用脉冲电晕等离子体法可转化丙烯和氧气直接生成环氧丙烷，适当调节上述各参数可提高环氧丙烷的收率．当反应气总流速为200mL／min，极间距为4mm，脉冲放电电压为18kV，放电频率为120Hz时，环氧丙烷的收率、丙烯的转化率及环氧丙烷的选择性分别为5．15％，19．15％和26．89％．

Direct Gas Phase Synthesis of Propylene Oxide Using Propylene-Oxygen Plasma

The role of plasma activation in the direct gas phase epoxidation of propylene with molecular oxygen is discussed for the first time. The plasma was obtained by applying pulse corona discharge to the mixture of oxygen and propylene at room temperature and atmospheric pressure by using a needle-plate reactor. The reaction mixture was analyzed by an on-line chromatography. The effects of some main parameters on propylene conversion, PO yield and PO selectivity, such as the space between the electrodes, the pulse discharge frequency as well as the pulse discharge voltage, were investigated. It is observed that, at room temperature and atmospheric pressure, propylene and oxygen can be directly converted into PO in gas phase only by plasma activation. The proper adjustment of above parameters can rise the yield of PO. When the pulse voltage of corona discharge is fixed at 18 kV, the yield of PO, the conversion of propylene and the selectivity of PO are 5.15%, 19.15% and 26.89%, respectively.