CO2 Fixation in Ca2+-/Mg2+-Rich Aqueous Solutions through Enhanced Carbonate Precipitation
CO2 Fixation in Ca2+-/Mg2+-Rich Aqueous Solutions through Enhanced Carbonate Precipitation
复制标题
通过强化碳酸盐沉淀将 CO2 固定在富含 Ca2/Mg2 的水溶液中
DOI：
10.1021/ie1025419
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发表时间：
2011-07-06
影响因子：
4.2
通讯作者：
Ma, Chunyuan
中科院分区：
文献类型：
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作者：
Wang, Wenlong;Hu, Mingqiang;Ma, Chunyuan
在这项工作中，测试和验证了使用Ca和Mg离子实现CO2固定的可能性。来自海水淡化厂的浓缩海水、地下盐水、高硬度的工业废水和/或富含Ca2+和Mg2+的天然海水都可能是潜在的水源。理论分析表明，提高pH值或CO2分压均可促进碳酸化反应。使用合成海水的实验证实了这种可能性。海水中超过90%的Ca2+和Mg2+离子可以通过沉淀以MgCO3和白云石[MgCa(CO3)(2)]的形式转化，并且发现该过程的动力学是可以接受的。研究发现，1 m(3)天然海水可以固定约1.34 m(3)或2.65 kg CO2（气体体积，标准条件），而浓缩海水的潜势是该值的2-3倍。即使以这种方式捕获全世界每年的二氧化碳排放量，天然海水中Ca2+/Mg2+的浓度也只会以百万分之一的比例变化，因此其生态效应可以忽略不计。这个想法有很大的应用潜力。它不仅可以实现二氧化碳的永久固定，而且可以产生大量的碳酸盐副产物。
In this work, the possibility of achieving fixation of CO2 using Ca and Mg ions was tested and verified. Concentrated seawater from desalination plants, subsurface brines, industrial effluents with high hardness, and/or natural seawaters that are rich in Ca2+ and Mg2+ could all be potential aqueous sources. Theoretical analyses indicated that the carbonation reaction could be enhanced by raising the pH or the CO2 partial pressure. Experiments using synthesized seawater confirmed this possibility. Over 90% of the Ca2+ and Mg2+ ions in the seawater could be converted by precipitation in the forms of MgCO3 and dolomite [MgCa(CO3)(2)], and the kinetics of the process was found to be quite acceptable. It was found that 1 m(3) of natural seawater could fix about 1.34 m(3) or 2.65 kg of CO2 (gas volume, standard conditions), and the potential of concentrated seawater is 2-3 times this value. Even if the annual CO2 emissions of the entire world were captured in this way, the concentration of Ca2+/Mg2+ in natural seawater would change at only the part-per-million scale, such that the ecological effects could be negligible. This idea has great potential for application. It might be able to realize not only the permanent fixation of CO2 but also the production of large amounts of carbonate byproducts.