Experimental Investigation and Simplistic Geochemical Modeling of CO₂ Mineral Carbonation Using the Mount Tawai Peridotite.

Omeid Rahmani,Mark Tyrer,Amin Pour,Radzuan Junin,James Highfield

doi:10.3390/molecules21030353

Abstract

In this work, the potential of CO2 mineral carbonation of brucite (Mg(OH)2) derived from the Mount Tawai peridotite (forsterite based (Mg)2SiO4) to produce thermodynamically stable magnesium carbonate (MgCO3) was evaluated. The effect of three main factors (reaction temperature, particle size, and water vapor) were investigated in a sequence of experiments consisting of aqueous acid leaching, evaporation to dryness of the slurry mass, and then gas-solid carbonation under pressurized CO2. The maximum amount of Mg converted to MgCO3 is ~99%, which occurred at temperatures between 150 and 175 °C. It was also found that the reduction of particle size range from >200 to <75 µm enhanced the leaching rate significantly. In addition, the results showed the essential role of water vapor in promoting effective carbonation. By increasing water vapor concentration from 5 to 10 vol %, the mineral carbonation rate increased by 30%. This work has also numerically modeled the process by which CO2 gas may be sequestered, by reaction with forsterite in the presence of moisture. In both experimental analysis and geochemical modeling, the results showed that the reaction is favored and of high yield; going almost to completion (within about one year) with the bulk of the carbon partitioning into magnesite and that very little remains in solution.

Highlights

Carbon dioxide (CO2 ) is the principal greenhouse gas released into the atmosphere during fuel combustion, due to the extensive use of fossil fuels for energy production from coal, oil, and natural gas since the industrial revolution [1]
Researchers have studied ways to mitigate the amount of greenhouse gases released into the atmosphere by sequestration of CO2 through different approaches, including aquifer storage, deep
The elemental composition of the peridotite mineral was determined by XRF analysis as magnesium oxide periclase (MgO)

Summary

Introduction

Carbon dioxide (CO2 ) is the principal greenhouse gas released into the atmosphere during fuel combustion, due to the extensive use of fossil fuels for energy production from coal, oil, and natural gas since the industrial revolution [1]. Researchers have studied ways to mitigate the amount of greenhouse gases released into the atmosphere by sequestration of CO2 through different approaches, including aquifer storage, deep. Ca2+ -rich minerals (e.g., olivine and gypsum) to form solid carbonates, which are expected to be stable over geologic time periods. % Mg, have the highest capacity to trap CO2 as magnesium carbonates, and a high rate of dissolution among rock-forming silicate minerals [16]. Formation of magnesite from forsterite, the Mg-end member of the olivine solid solution series, is thermodynamically favorable based on the negative Gibbs free energy of Reaction (1)

Objectives

Methods

Conclusion