...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Environmental Science & Technology >Carbon sequestration via aqueous olivine mineral carbonation: Role of passivating layer formation
【24h】

Carbon sequestration via aqueous olivine mineral carbonation: Role of passivating layer formation

机译：通过橄榄石矿物碳酸水溶液固碳：钝化层形成的作用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

CO2 sequestration via carbonation of widely available low-cost minerals, such as olivine, can permanently dispose of CO2 in an environmentally benign and a geologically stable form. We report the results of studies of the mechanisms that limit aqueous olivine carbonation reactivity under the optimum sequestration reaction conditions observed to date: 1 M NaCl + 0.64 M NaHCO3 at T approximate to 185 C and P CO2 approximate to 135 bar. A reaction limiting silica-rich passivating layer (PL) forms on the feedstock grains, slowing carbonate formation and raising process cost. The morphology and composition of the passivating layers are investigated using scanning and transmission electron microscopy and atomic level modeling. Postreaction analysis of feedstock particles, recovered from stirred autoclave experiments at 1500 rpm, provides unequivocal evidence of local mechanical removal ( chipping) of PL material, suggesting particle abrasion. This is corroborated by our observation that carbonation increases dramatically with solid particle concentration in stirred experiments. Multiphase hydrodynamic calculations are combined with experiment to better understand the associated slurry-flow effects. Largescale atomic-level simulations of the reaction zone suggest that the PL possesses a "glassy" but highly defective SiO2 structure that can permit diffusion of key reactants. Mitigating passivating layer effectiveness is critical to enhancing carbonation and lowering sequestration process cost.
机译：通过碳酸化广泛获得的低成本矿物（例如橄榄石）进行的二氧化碳封存可以永久性地以对环境无害且地质稳定的形式处置二氧化碳。我们报告了在迄今为止观察到的最佳螯合反应条件下限制水性橄榄石碳酸反应性的机理的研究结果：1 M NaCl + 0.64 M NaHCO3在T处大约为185 C，P CO2大约为135 bar。在原料颗粒上形成反应受限的富含二氧化硅的钝化层（PL），减缓了碳酸盐的形成并增加了工艺成本。使用扫描和透射电子显微镜以及原子能级模型研究钝化层的形态和组成。从搅拌高压釜实验中以1500 rpm的速度回收的原料颗粒的后反应分析提供了PL材料局部机械去除（碎裂）的明确证据，表明颗粒磨损。我们的观察结果证实了这一点，即在搅拌实验中碳化随着固体颗粒浓度的增加而急剧增加。多相流体力学计算与实验相结合，可以更好地理解相关的泥浆流效应。反应区的大规模原子级模拟表明，PL具有“玻璃状”但高度缺陷的SiO2结构，可以使关键反应物扩散。减轻钝化层的有效性对于增强碳化和降低隔离过程的成本至关重要。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号