当前位置: X-MOL 学术Environ. Sci. Technol. Lett. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Role of Fe(II) Content in Olivine Carbonation in Wet Supercritical CO2
Environmental Science & Technology Letters ( IF 8.9 ) Pub Date : 2019-09-04 , DOI: 10.1021/acs.estlett.9b00496
Cecelia E. Wood 1 , Odeta Qafoku 1 , John S. Loring 1 , Anne M. Chaka 1
Affiliation  

Basalt geologic reservoirs are targeted for carbon storage because they are abundant in divalent silicates such as olivine [(Mg,Fe)2SiO4] that can carbonate to permanently trap CO2. Under reservoir conditions, CO2 is a supercritical fluid that contains dissolved H2O, which adsorbs to minerals as nanometer thin films. In this study, the role of Fe(II) in the thin H2O film carbonation of olivine was investigated using in situ high-pressure infrared spectroscopy and ab initio thermodynamic calculations. Experiments were performed at 50 °C and 90 bar in both supercritical CO2 and supercritical CO2 with 1% H2 at a relative humidity of 79% on synthetic forsterite, fayalite, and two Mg/Fe mixture olivines, (MgxFe1–x)2SiO4 (x = 0.33 and 0.66). Carbonation rates and extents are lower with increasing concentrations of Fe(II) in the olivine, but the addition of 1% H2 increases the level of carbonation in Fe(II)-rich olivines. These trends are explained according to the dependencies of olivine acidic solubilities, carbonate precipitation equilibria, and dissolution/growth kinetics on Fe(II) content and by considering that Fe(II)-rich olivines can undergo competing oxidation reactions by O2 and H2O to form Fe(III)-containing oxides. Given that CO2 injected into the subsurface will be relatively oxic, the oxidation of Fe(II)-rich olivines could impact their carbonation potential.

中文翻译:

Fe(II)含量在湿超临界CO2中橄榄石碳化中的作用

玄武岩地质储层是碳储藏的目标,因为它们富含橄榄石[(Mg,Fe)2 SiO 4 ]等二价硅酸盐,可以碳酸盐永久捕获CO 2。在储层条件下,CO 2是一种超临界流体,其中包含溶解的H 2 O,它以纳米薄膜的形式吸附到矿物上。在这项研究中,使用原位高压红外光谱和从头算热力学计算研究了Fe(II)在橄榄石H 2 O薄膜碳酸化中的作用。实验是在50°C和90 bar的超临界CO 2和含1%H 2的超临界CO 2中进行的在合成镁橄榄石,铁橄榄石和两种Mg / Fe混合橄榄石(Mg x Fe 1- x2 SiO 4x = 0.33和0.66)上,相对湿度为79%。随着橄榄石中Fe(II)浓度的增加,碳酸化速率和程度会降低,但是1%H 2的添加会增加富Fe(II)橄榄石中碳酸化程度。这些趋势是根据橄榄石酸性溶解度,碳酸盐沉淀平衡以及Fe / II含量的溶解/生长动力学的相关性,并考虑到富含Fe(II)的橄榄石可以通过O 2和H 2进行竞争性氧化反应来解释的O形成含Fe(III)的氧化物。考虑到注入地下的CO 2相对有氧,富Fe(II)的橄榄石的氧化可能会影响其碳化潜力。
更新日期:2019-09-04
down
wechat
bug