RESUMO
A novel process is reported that produces amorphous silica and nesquehonite (MgCO3·3H2O) from the magnesium silicate mineral olivine ((Mg, Fe)2·SiO4). The amorphous silica forms a supplementary cementitious material for use in concrete. The formation of nesquehonite sequesters carbon making the overall process carbon negative. Nesquehonite can also be used to form low-carbon construction products such as bricks, blocks and boards. This article reports on key process optimization studies. The potential for amorphous precipitated silica derived from olivine to produce carbon-negative concrete is discussed.
RESUMO
This work describes the first report of the use of an aminosilicone solvent mix for the capture of CO(2). To maintain a liquid state, a hydroxyether co-solvent was employed which allowed enhanced physisorption of CO(2) in the solvent mixture. Regeneration of the capture solvent system was demonstrated over 6 cycles and absorption isotherms indicate a 25-50 % increase in dynamic CO(2) capacity over 30 % MEA. In addition, proof of concept for continuous CO(2) absorption was verified. Additionally, modeling to predict heats of reaction of aminosilicone solvents with CO(2) was in good agreement with experimental results.