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)沉积式反应器和(2)冲刷式反应器。在沉积型反应器中，电晕放电产生的负离子在阳极表面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。一定量的气体通过气缸被扫出，从阳极中除去具有高浓度亲电成分的气体。对硫化合物、氧和碘的去除率进行了研究。沉积式反应器中硫化氢、二甲基硫化物、甲硫醇、二氧化硫、羰基硫化物和二硫化碳均可脱除，并利用所建立的仿真模型解释了放电电流、进口浓度和气体流速对脱除率的影响。当氧共存时，含硫化合物的去除率高，产生反应副产物。当放电电流变大时，副产物可以忽略不计。用电子探针显微分析（EPMA）观察了阳极表面沉积的硫。扫掠式反应器除氧除碘，并利用所建立的模型对氧和碘的去除率进行模拟。模拟结果表明，反应器的形状决定了反应器的去除率，在一定的反应器体积下，反应器半径越大，去除率越好。从进口浓度、气体流速、电子附着速率常数和负离子在阳极表面沉积概率的平衡中确定了最佳操作条件。

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.