文献类型：期刊文献

英文题名：Density functional theory study on the thermodynamics and mechanism of carbon dioxide capture by CaO and CaO regeneration

作者：Sun, Ze[1];Wang, Jia[1];Du, Wei[1];Lu, Guimin[1];Li, Ping[1];Song, Xingfu[1];Yu, Jianguo[1]

机构：[1]E China Univ Sci & Technol, Natl Engn Res Ctr Integrated Utilizat Salt Lake R, Shanghai 200237, Peoples R China

年份：2016

卷号：6

期号：45

起止页码：39460

外文期刊名：RSC ADVANCES

收录：;EI(收录号：20162102415406);WOS:【SCI-EXPANDED(收录号:WOS:000374972800118)】；

基金：We acknowledge the financial support provided by the National Natural Science Foundation of China (Grant U1407126), Capacity Building of Qinghai Engineering Research Center for Integrated Utilization of Salt Lake (Grant 2015-GX-Q19A), and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Thermodynamics - Calcination - Calcium carbonate - Density functional theory - Activation energy - Calcite - Carbonation

摘要：Reducing CO2 emission is one of the most important events to solve the global climate problem. The carbonation reaction of CaO and the reverse reaction are potential methods for CO2 capture and concentration from dilute flue gases at high temperature. In this paper, the thermodynamics and mechanisms of CO2 capture by CaO and CaO regeneration from CaCO3 were studied and identified in the framework of density functional theory (DFT). In the calculation, the exchange-correlation term was approximated by Perdew-Wang (PW91), a function within the generalized gradient approximation (GGA) family. The reaction energies of carbonation reaction and calcination reaction were calculated to be -147.64 kJ mol(-1) and 180.60 kJ mol(-1), respectively. To study the reaction between CO2 and CaO, the transition states of carbonation and calcination were also analyzed. The results showed that the carbonation of CaO was rather fast, and the activation energy of carbonation reaction was 0 kJ mol(-1), which indicated that the reaction process was not the rate-determining step during the process of CO2 capture. The regeneration of CaO by CaCO3 calcination occurred at higher temperature, with the activation energy of 166.85 kJ mol(-1), and the rate of calcination was controlled by the chemical reaction.