富钙镁离子溶液以碳酸盐沉淀固定CO_2的试验研究

Experimental Study on C0_2 Fixation in the Form of Ca/Mg Carbonate Precipitation in Solutions

提出了利用富钙镁离子溶液(海水淡化产生的浓海水、地下卤水、高硬度工业废水等)以碳酸盐沉淀形式实现CO_2固定的思路,以2倍浓度的海水为例进行分析,表明富钙镁离子溶液具有可观的固碳潜力。考察了氨水-氯化铵溶液、氨水-碳酸氢铵溶液和有机胺(MEA、MDEA)作为添加剂提高溶液pH值的方式对碳酸盐沉淀形成能力的影响。结果表明这三种添加剂均可在一定程度上提高溶液pH值,促进富钙镁离子溶液中难溶碳酸盐沉淀形成。

An idea of achieving CO2 fixation in the form of carbonate precipitation using Ca2＋/Mg2＋- rich aqueous solutions is put forward. Condensed seawater from desalination plants, subsurface brines, as well as industrial effluents with high hardness may all be available sources. The analysis based on condensed seawater indicates that the method is promising in CO2 fixation. In experiments, ammonia water-ammonium bicarbonate solution, ammonia water-ammonium chloride solution and organic amine （MEA, MDEA） were employed as additives and their effects were studied. It is shown that all the three kinds of additive can raise the pH of the solution in different degree and promote the formation of carbonate precipitation.