Transformation of abundant magnesium silicate minerals for enhanced CO2 sequestration

Abstract

Global climate change related to anthropogenic CO2 emissions is one of the most significant challenges for the future of human life on Earth. There are many potential options for reducing or even eliminating atmospheric CO2 emissions including underground sequestration, carbon mineralization and ocean storage. One of the most promising materials for carbon mineralization is Mg(OH)2 which is highly reactive and capable of forming stable carbonates. Here we show a novel low-carbon method of producing Mg(OH)2, from globally abundant olivine-rich silicate rocks. A combination of acid digestion and electrolysis of olivine were used to produce Mg(OH)2 in a fully recoverable system. The use of Mg(OH)2 from olivine provides a viable pathway for significant industrial scale reductions in global anthropogenic greenhouse gas emissions.

Effect of carbonates on the formation of magnesium silicate hydrates

“…The raw materials do not decarbonate naturally occurring carbonates as in the production of Portland-based cement, but use magnesium silicates or Mg containing brines as source materials [1]. MOMS production requires some processing to gain magnesium carbonates from magnesium silicates [2,3]. Furthermore, the calcination temperature of such magnesium carbonates (&800 °C) is significantly lower than the clinkering temperature of Portland cement [1].…”

Unveiling redox mechanism at the iron centers in the mechanochemically activated conversion of CO2 in the presence of olivine

“…Mineral weathering is probably the main natural process observed in our planet for recycling carbon dioxide: It is well known, in fact, that more than 100 million tons of carbon per year are sequestrated through silicate weathering [ 5 ]. In this regard, minerals with a high magnesium content such as serpentine and olivine represent the best candidates for this application [ 6 , 7 ]. Olivine is one of the most abundant minerals on Earth: It constitutes mafic and ultramafic igneous rocks covering more than 84% in volume of the terrestrial mantle.…”

Deriving Nickel (Ni(II)) and Chromium (Cr(III)) Based Environmentally Safe Olivine Guidelines for Coastal Enhanced Silicate Weathering

“…The mineral olivine (Mg 2 x Fe 2(1– x ) SiO 4 ) is a prime candidate for coastal ESW because of its relatively fast dissolution rate and widespread abundance. − Billions of tonnes of olivine are globally present in mafic and ultramafic igneous rocks, and each year approximately 8 Mt is mined from dunite (rock containing >90% olivine) or serpentinite (metamorphosed olivine-rich ultramafic rock) deposits for metallurgical use. − Relatively low energy costs and low CO 2 emissions associated with grinding olivine source rock to 100 μm particles make this a desirable grain size for use in coastal ESW . However, several studies indicate that grain sizes of 10 μm or smaller might be needed to ensure significant olivine dissolution and CO 2 uptake in the coming decades. ,, …”