Thermodynamic parameters of 135 gaseous PCDF calculated with DFT  

作　　者：Yongmei Yu Oleszek.Kudlak Sylwia Xiaodan Dong Xianwei Li 

机构地区：[1]Baosteel Research Institute, Baoshan Iron ＆ Steel Co. , Ltd. , Shanghai 201900, China [2]Institute of Environmental Engineering, Polish Academy of Sciences, M. urie-Sklodowska 34, 41-819 Zabrze, Poland [3]Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China

出　　处：《Baosteel Technical Research》2007年第1期32-36,共5页宝钢技术研究（英文版）

摘　　要：Numerous thermal processes （e.g. waste incineration, steel and nonferrous industry, wastes recycling plants, hot dip galvanizing etc. ） have been identified as emission sources of PolyChlorinated Dibenzo-p-Dioxins （PCDD） and PolyChlorinated DibenzoFurans （PCDF）, which are named in brief ＂dioxins＂ The processes by which such dioxins （PCDD/F） are formed are still incompletely understood and probably proceed catalytically by multiple and parallel pathways. However, two major pathways of formation have been identified during final stages of the combustion process： The first one is the precursor route, i.e. the formation of PCDD/F from related structures, such as simple or chlorinated benzenes, phenols, biphenyls, and polycyclic aromatic hydrocarbons （PAH）, and the second one is the de novo synthesis of PCDD/F from macromolecular solid carbon （ or other structures unrelated to dioxins）, organic and inorganic chlorine, oxygen, etc. Knowledge of the relevant thermodynamic parameters is essential for predicting possible stability domains of PCDD/F during combustion processes and their equilibrium distribution at emission sources. In the previous study, thermodynamic parameters of PCDDi predicted with density functional theory （DFF） method have been reported. A comprehensive thermodynamic database of the standard entropy （ S^0 ）, specific heat （Cp）, enthalpy of formation （ΔfH^0） and Gibbs free energy of formation （ΔfG^0） for 135 gaseous PCDF （including dibenzofuran） was studied. From the enthalpies of formation the order of stability of individual congeners is reported. Additionally, the results obtained in this study are compared with values determined by other electronic structural methods.Numerous thermal processes （e.g. waste incineration, steel and nonferrous industry, wastes recycling plants, hot dip galvanizing etc. ） have been identified as emission sources of PolyChlorinated Dibenzo-p-Dioxins （PCDD） and PolyChlorinated DibenzoFurans （PCDF）, which are named in brief ＂dioxins＂ The processes by which such dioxins （PCDD/F） are formed are still incompletely understood and probably proceed catalytically by multiple and parallel pathways. However, two major pathways of formation have been identified during final stages of the combustion process： The first one is the precursor route, i.e. the formation of PCDD/F from related structures, such as simple or chlorinated benzenes, phenols, biphenyls, and polycyclic aromatic hydrocarbons （PAH）, and the second one is the de novo synthesis of PCDD/F from macromolecular solid carbon （ or other structures unrelated to dioxins）, organic and inorganic chlorine, oxygen, etc. Knowledge of the relevant thermodynamic parameters is essential for predicting possible stability domains of PCDD/F during combustion processes and their equilibrium distribution at emission sources. In the previous study, thermodynamic parameters of PCDDi predicted with density functional theory （DFF） method have been reported. A comprehensive thermodynamic database of the standard entropy （ S^0 ）, specific heat （Cp）, enthalpy of formation （ΔfH^0） and Gibbs free energy of formation （ΔfG^0） for 135 gaseous PCDF （including dibenzofuran） was studied. From the enthalpies of formation the order of stability of individual congeners is reported. Additionally, the results obtained in this study are compared with values determined by other electronic structural methods.

关 键 词：PCDF density functional theory （DFF） specific heat enthalpy of formation ENTROPY 

分 类 号：TF7[冶金工程—钢铁冶金]