Detoxification of persistent organic compounds by a combination of plasma decomposition with in-situ halogen absorption

本文研究了有机卤化物气体在N_2、O_2N_2和H_2-N_2气氛下的非热等离子体分解行为。此外，为了通过原位捕获卤素来抑制卤素副产物的形成和有效地解毒卤化物，采用等离子体分解结合碱性吸附剂原位气体吸收的方法研究了有机卤化物气体的分解。在O_2-N_2气氛下等离子体分解卤化物气体（CCl_4、CHF_3和CHClF_2）时，卤化物气体的分解率比在N_2气氛下的分解率低。卤化物气体结构中碳(C)氧化生成的CO_2量随着O_2浓度的增加而增加。在N_2气氛下分解CHClF_2时，检测到CCl_2F_2、HF、HCl、F_2和Cl_2， O_2-N_2气氛下还生成COF_2和COCl_2。在H_2-N_2气氛中，CF_4、CHF_3、CHClF_2和SF_6的等离子体分解次数较多，CF_4、CHC1lF_2和SF_6的分解率高于N_2气氛。H_2存在时，CHF_3的分解率降低。SF_6在H_2-N_2气氛中分解生成副产物H_2S和HF，并在N_2气氛中生成F_2。当等离子体分解与Ca(OH)_2吸附剂的原位气体吸收相结合时，CHClF_2在O_2-N_2气氛中分解，CHF_3在H_2-N_2气氛中分解，卤化物的分解率比没有Ca(OH)_2时提高。在O_2-N_2气氛下，原位碱性吸附剂存在时，CHClF_2等离子体分解生成的CO_2量高于无碱性吸附剂存在时。此外，发现CHClF_2结合原位气体吸收的等离子体分解过程中，出口气体中HF和COCl_2等卤素副产物的生成明显受到抑制。因此，我们的工作证明了原位碱性吸收剂存在于等离子体反应领域的可能性，以实现有效的等离子体分解卤化物气体和去除有害副产物。少

In this research, the behavior of non-thermal plasma decomposition of organic halide gases in N_2,O_2N_2 and H_2-N_2 atmospheres was studied. In addition, for the purpose of inhibition of the formation of halogen byproducts and effective detoxification of halides by the in-situ capture of the halogen species, the decomposition of organic halide gases was investigated using a technique of plasma decomposition combined with in-situ gas absorption by alkaline absorbent.On the plasma decomposition of halide gases (CCl_4,CHF_3 and CHClF_2) in the O_2-N_2 atmosphere, the decomposition ratios of halide gases were lower compared to those in N_2 atmosphere. The amount of CO_2 formed by the oxidation of the carbon (C) in the structure of halide gases was increased with the increase of the concentration of O_2. During the decomposition of CHClF_2 under N_2 atmosphere, CCl_2F_2,HF, HCl,F_2 and Cl_2 were detected, while, in addition, COF_2 and COCl_2 were formed under O_2-N_2 atmosphere. In the cas … More e of the plasma decomposition of CF_4,CHF_3,CHClF_2 and SF_6 in H_2-N_2 atmosphere, the decomposition ratios of CF_4,CHC1lF_2 and SF_6 were higher compared to those in N_2 atmosphere. However, the decomposition ratio of CHF_3 decreased in the presence of H_2. H_2S and HF were formed as the byproducts in the decomposition of SF_6 in H_2-N_2 atmosphere, in addition to F_2 formed in N_2 atmosphere.When the plasma decomposition was incorporated with in-situ gas absorption by Ca(OH)_2 absorbent on the decomposition of CHClF_2 in O_2-N_2 atmosphere and CHF_3 in H_2-N_2 atmosphere, the decomposition ratios of halides increased, compared to that without Ca(OH)_2. In O_2-N_2 atmosphere, the amount of CO_2 formed during the plasma decomposition of CHClF_2 in the presence of in-situ alkaline absorbent was higher than that without alkaline absorbent. Moreover, it was found that the generation of the halogen byproducts such as HF and COCl_2 in outlet gas was significantly inhibited in plasma decomposition of CHClF_2 incorporated with in-situ gas absorption.As a result, our work demonstrated the possibility of in-situ alkaline absorbent present in the plasma reaction field to achieve the effective plasma decomposition of halide gases and removal of harmful byproducts. Less