Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 2 de 2
Filter
Add more filters










Database
Language
Publication year range
1.
Phys Chem Chem Phys ; 26(12): 9264-9283, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38446193

ABSTRACT

The rising need to produce a decarbonized supply chain of energy critical metals with inherent carbon mineralization motivates advances in accelerating novel chemical pathways in a mechanistically-informed manner. In this study, the mechanisms underlying co-recovery of energy critical metals and carbon mineralization by harnessing organic ligands are uncovered by investigating the influence of chemical and mineral heterogeneity, along with the morphological transformations of minerals during carbon mineralization. Serpentinized peridotite is selected as the feedstock, and disodium EDTA dihydrate (Na2H2EDTA·2H2O) is used as the organic ligand for metal recovery. Nickel extraction efficiency of ∼80% and carbon mineralization efficiency of ∼73% is achieved at a partial pressure of CO2 of 50 bars, reaction temperature of 185 °C, and 10 hours of reaction time in 2 M NaHCO3 and 0.1 M Na2H2EDTA·2H2O. Extensive magnesite formation is evidence of the carbon mineralization of serpentine and olivine. An in-depth investigation of the chemo-morphological evolution of the CO2-fluid-mineral system during carbon mineralization reveals several critical stages. These stages encompass the initial incongruent dissolution of serpentine resulting in a Si-rich amorphous layer acting as a diffusion barrier for Mg2+ ions, subsequent exfoliation of the silica layer to expose unreacted olivine, and the concurrent formation of magnesite. Organic ligands such as Na2H2EDTA·2H2O aid the dissolution and formation of magnesite crystals. The organic ligand exhibits higher stability for Ni-complex ions than the corresponding divalent metal carbonate. The buffered environment also facilitates concurrent mineral dissolution and carbonate formation. These two factors contribute to the efficient co-recovery of nickel with inherent carbon mineralization to produce magnesium carbonate. These studies provide fundamental insights into the mechanisms underlying the co-recovery of energy critical metals with inherent carbon mineralization which unlocks the value of earth abundant silicate resources for the sustainable recovery of energy critical metals and carbon management.

2.
Micron ; 154: 103195, 2022 03.
Article in English | MEDLINE | ID: mdl-35051800

ABSTRACT

Sedimentary rocks are known for their complex pore system with varying morphology due to intricate diagenetic processes. The present study demonstrates the applicability of image analysis in analysing and defining reservoir rock properties. Conventional techniques provide quantitative results but fail to give information about the internal microstructure of the rock. On the other hand, digital image techniques reveal the micro and macro-pore types and their connectivity across multiple scales. Hence, we performed the digital image analysis on Field Emission Scanning Electron Microscopy (FESEM) images of sandstone and carbonate samples collected from the upper Assam and Bombay offshore basins. FESEM derived image analysis was used exclusively due to its several unique features over contemporary techniques involving lesser data acquisition, simulation time and performing analysis even on a rock chip obtained while drilling the borehole. Porosity was evaluated based on the percentage of pores available within the image, and permeability was evaluated using the Kozeny-Carman equation. Further, we developed statistical equations to understand the existence of coherence amongst these parameters. Our study shows that we could determine both open and closed porosities by this method. In addition, there is an agreement between the conventional porosity measurement and image-derived porosity for most rock samples, especially for very low and high porosity. Further, this study highlights the importance of thresholding, an essential component in evaluating porosity using digital images. We propose that the methodology developed can accurately characterise reservoirs based on pore networks using high-resolution imaging techniques. The developed methodology may be adopted to promote best practices. Since we used digital images obtained from small chip size rock samples, this method is advantageous to quickly calculate the porosity and permeability from rock chips retrieved from the sieve shaker while drilling. Digital datasets extracted from this analysis will be helpful for reservoir description and characterisation based on image-derived petrophysical parameters.


Subject(s)
Carbonates , Image Processing, Computer-Assisted , Microscopy, Electron, Scanning , Permeability , Porosity
SELECTION OF CITATIONS
SEARCH DETAIL
...