Development of Gas Purification Technology Based on Selective electron Attachment

两种不同类型的反应器用于气体净化：(1)沉淀型反应器和(2)清扫式反应器。在沉积式反应器中，电晕放电产生的负离子失去电子后沉积在阳极表面。扫出式反应器的阳极是由烧结金属制成的多孔圆柱体。通过这个气瓶，一定量的气体被扫出，将含有高浓度亲电成分的气体从阳极上去除。在脱除硫化物、氧和碘方面取得了如下结果。沉淀型反应器可脱除硫化氢、二甲基硫化物、甲硫醇、二氧化硫、羰基硫化物和二硫化碳，并能解释放电电流、进气浓度和气体流量对脱除率的影响。当氧气共存时，硫化物的脱除率较高，并产生反应副产物。当放电电流变大时，副产物可以忽略不计。用电子探针(EPMA)观察了阳极表面沉积的硫。扫除式反应器可以去除氧气和碘，并且可以用所提出的模型模拟除氧率。模拟结果表明，反应器的形状对去除效果有影响，在一定的反应器体积下，反应器半径越大，去除效果越好。从进气浓度、气体流量、电子附着速率常数和负离子在阳极表面沉积几率的平衡来确定最佳操作条件。

Two different types of reactors are constructed for gas purification ; (1) Deposition type reactor and (2) Sweep-out type reactor. In the deposition type reactor, the negative ions produced by corona discharge deposit on the anode surface after they lose the electron there. The anode of the sweep-out type reactor is a porous cylinder made of sintered metal. Through this cylinder a certain amount of gas is swept out to remove the gas with high concentration of electrophilic component from the anode. The following results on the removal of sulfur compound, oxygen and iodine were obtained.1. Deposition type reactorHydrogen sulfide, dimethyl sulfide, methyl mercaptan, sulfur dioxide, carbonyl sulfide and carbon disulfide can be removed in the deposition type reactor, and the influence of discharge current, inlet concentration and gas flow rate on the removal ratio can be explained using the proposed simulation model. When oxygen coexists, the removal ratio of sulfur compounds becomes high and reaction by-products are produced. The by-products can be neglected as the discharge current becomes large. The sulfur deposited on the anode surface was observed by an electron probe micro-analysis (EPMA).2. Sweep-out type reactorOxygen and iodine can be removed by the sweep-out type reactor, and the removal ratio can be simulated using the proposed model. The simulated results show that the removal ratio depends on the reactor shape and the larger radius of reactor gives a better removal ratio under a given reactor volume. The optimum operating conditions are determined from the balance of inlet concentration, gas flow rate, rate constant of electron attachment and deposition probability of negative ions on the anode surface.