X-ray Studies of Carbon Dioxide Intercalation in Na-Fluorohectorite Clay at Near-Ambient Conditions

Abstract

We show experimentally that gaseous CO2 intercalates into the interlayer space of the synthetic smectite clay Na-fluorohectorite at conditions not too far from ambient. The mean interlayer repetition distance of the clay when CO2 is intercalated is found to be 12.5 Å for the conditions -20 °C and 15 bar. The magnitude of the expansion of the interlayer upon intercalation is indistinguishable from that observed in the dehydrated-monohydrated transition for H2O, but the possibility of water intercalation is ruled out by a careful analysis of the experimental conditions and repeating the measurements exposing the clay to nitrogen gas. The dynamics of the process is observed to be dependent on the pressure, with a higher Page 2 of 15 intercalation rate at increased pressure. The rate of CO2 intercalation at the studied conditions is found to be several orders of magnitude slower than the intercalation rate of water or humidity at ambient pressure and temperature.

Molecular Simulation of CO2- and CO3-Brine-Mineral Systems

“…The adsorption of CO 2 in clay nanopores has been mainly considered in the absence of water. Experimentally, the incorporation of CO 2 in pyrophyllite during dehydroxylation has been observed by infrared spectroscopy (Wang et al 2003) and X-ray diffraction has allowed following the intercalation of CO 2 in Na-fluorohectorite near ambient conditions: the expansion in basal spacing is similar to that obtained during intercalation with water, but it occurs at a rate that is several orders of magnitude slower (Hemmen et al 2012). The density of CO 2 confined in Na-montmorillonite with a sub-single hydration layer depends on the bulk scCO 2 density (Rother et al 2013).…”

Competitive sorption of CO2 and H2O in 2:1 layer phyllosilicates

“…Giesting et al (2012a) and Hemmen et al (2012) also proposed CO 2 intercalation of montmorillonite under supercritical as well as sub-critical conditions based on in situ XRD experiments. More recently, swelling strain experiments with nearly dry montmorillonites produced volume changes in the presence of scCO 2 leading to possible implications about reservoir permeability (de Jong et al, 2014).…”

Supercritical Carbon Dioxide at Smectite Mineral–Water Interfaces: Molecular Dynamics and Adaptive Biasing Force Investigation of CO2/H2O Mixtures Nanoconfined in Na-Montmorillonite

“…1,6,[18][19][20][21][22][23][24][25][26][27][28][29]38,57,58,60,[64][65][66][67] Because of their common natural occurrence, they may also play an important role in geological CO 2 -sequestration reservoirs. 1,6,[18][19][20][21][22][23][24][25][26][27][28][29]38,67,57,58,60,[64][65][66][67] The affinity and specificity of oxide surfaces for intercalates can be controlled by a variety of compositional and structural parameters including substitutions in the tetrahedral and octahedral layers, variability in charge-balancing cations, and coatings of functionalized organic compounds. [38][39][40]...…”

“…43,[48][49][50][68][69][70][71][72][73] With respect to CO 2 incorporation in smectite interlayer galleries, several recent in situ high-pressure and temperature experimental X-ray diffraction, Infrared (IR), and NMR studies have shown that CO 2 enters the interlayer galleries at supercritical CO 2 -sequestration reservoir conditions and affects the structural environments and dynamics of interlayer cations. [18][19][20][21][22][23][24][25][26][27][28][29]58 For instance, Schaef et. al., 62 estimated the amount of CO 2 in the interlayer of dry sodium montmorillonite (Na-MMT) using quartz crystal microbalance (QCM) measurements while Loring et.…”