Abstract:

Two low-temperature plasma generation methods, corona discharge and dielectric barrier discharge(DBD), are used to purify hydrogen cyanide (HCN), and the reaction mechanisms of the two are discussed. The results show that the purification efficiency of HCN is 76% when the specific input energy (SIE) is 8.3 kJ/L in corona discharge, and 94% when SIE is 11.9 kJ/L in dielectric barrier discharge. By using density functional theory (DFT) to introduce external electric field, Gaussian software is used to calculate and analyze the differences between the two different discharge modes in the HCN purification process. After the introduction of external electric field, the molecular structure and system energy of HCN molecules have changed. In corona discharge, OCN, the intermediate product of HCN conversion, is mainly converted into CO₂ and N₂, while in dielectric barrier discharge HCN is more easily combined with OH in the system to form H₂O and —CN, and —CN will be polymerized into C₃N₄ under the action of high electron and particle density in DBD.

Key words: hydrogen cyanide, corona discharge, dielectric barrier discharge, density functional theory

摘要：

利用电晕放电以及介质阻挡放电两种低温等离子体产生方式净化氰化氢（HCN），同时对二者的反应机理进行探讨。结果表明，在电晕放电中当输入能量比（SIE）达到8.3 kJ/L，HCN净化效率为76%，在介质阻挡放电中当SIE为11.9 kJ/L时，HCN净化效率为94%；通过Gaussian 软件利用密度泛函理论（DFT）引入外电场，计算分析了两种不同放电方式在HCN净化过程中的差异，在引入外电场之后HCN分子的分子结构以及体系能量均发生了变化，在不同的放电方式中，HCN转化的中间产物—OCN在电晕放电中主要转化为CO₂与N₂，而在介质阻挡放电中HCN更容易与体系中—OH结合生成H₂O与—CN，—CN会在介质阻挡放电中的高电子、粒子密度的作用下聚合为C₃N₄。

关键词: 氰化氢, 电晕放电, 介质阻挡放电, 密度泛函理论