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Development promotion of highly effective desulfurizers of calcium compounds by molecular dynamic simulatons

分子动力学模拟促进钙化合物高效脱硫剂的开发

基本信息

批准号：
13650811
负责人：
NARUSE Ichiro
金额：
$ 0.32万
依托单位：
Toyohashi University of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650811/
关键词：
Desulfurization Molecular dynamics Sulfur oxides Coal combustion Alkali metal compounds Limestone Fluidized bed combustion

项目摘要

The effect of the alkali metal compounds on the desulfurization characteristics was elucidated quantitatively and theoretically in this study. The desulfurization experiments by adding some alkali metal compounds and chlorides to limestone were carried out, using a thermobalance. The mechanism on the enhancement of desulfurization characteristics were elucidated, based on the chemical and physical change of structure due to alkali metal compounds addition as well as structure change of CaO calculated by molecular dynamics simulation. Obtained results show that addition of NaCl into the limestone was found to be the most effective on improving the desulfurization efficiency. In order to elucidate in details the effect of the NaCl-doping on such structure change, the crystal structures of calcined seashell, limestone and NaCl-doped limestone were analyzed by X-ray diffraction (XRD), Consequently, CaO in both seashell and NaCl-doped limestone was crystallized, whereas CaO in the calcined … More limestone was disordered. Therefore, NaCl-doping can change the CaO crystal structure. From those experimental facts, the desulfurization characteristics are influenced by result of the crystal structure of samples after calcination. Next, the crystal structures for pure CaO and NaCl-doped CaO were simulated, using molecular dynamics simulation, in order to confirm the effect of NaCl-doping on the CaO structure theoretically. The results show that NaCl-doping into CaO contributes to the crystallization of CaO even at the temperatures of formation of amorphous structure for the pure CaO. Additionally, KC1 and LiCl-doped CaO was simulated under the same calculation conditions and procedures. Finally, only NaCl stably exists as the CaO crystal, while NaCl-doping showed predominant effect on the CaO crystallization. These tendencies depend on the difference of the potential energy and ionic radius of each alkali metal chloride. The experimental and simulation results obtained suggested that NaCl-doping contributed to crystallizing the CaO molecules. Less

本研究从定量和理论上阐明了碱金属化合物对脱硫特性的影响。利用热天平进行了在石灰石中添加一些碱金属化合物和氯化物的脱硫实验。基于碱金属化合物的添加引起的化学和物理结构变化以及通过分子动力学模拟计算的CaO的结构变化，阐明了增强脱硫特性的机理。所得结果表明，在石灰石中添加氯化钠对提高脱硫效率最有效。为了详细阐明 NaCl 掺杂对其结构变化的影响，通过 X 射线衍射（XRD）分析了煅烧贝壳、石灰石和 NaCl 掺杂石灰石的晶体结构，结果发现，贝壳和 NaCl 掺杂石灰石中的 CaO 都是结晶的，而煅烧石灰石中的 CaO 是无序的。因此，氯化钠掺杂可以改变CaO晶体结构。从这些实验事实来看，脱硫特性受到煅烧后样品晶体结构结果的影响。接下来，利用分子动力学模拟方法对纯CaO和NaCl掺杂CaO的晶体结构进行了模拟，以从理论上证实NaCl掺杂对CaO结构的影响。结果表明，即使在纯 CaO 形成非晶结构的温度下，CaO 中的 NaCl 掺杂也有助于 CaO 的结晶。此外，在相同的计算条件和程序下模拟了 KCl 和 LiCl 掺杂的 CaO。最后，只有 NaCl 以 CaO 晶体的形式稳定存在，而 NaCl 掺杂对 CaO 结晶表现出主要影响。这些趋势取决于每种碱金属氯化物的势能和离子半径的差异。实验和模拟结果表明，NaCl 掺杂有助于 CaO 分子的结晶。较少的