Accelerated carbon mineralization processes utilize Ca- or Mg-derived feedstocks to generate metal carbonates in a few minutes or hours using
# Chemically Accelerated Carbon Mineralization | ARPA-E. A **.gov** website belongs to an official government organization in the United States. #### Project Details. ##### Project Contact. The use of carbon mineralization as a CO 2 capture and storage method is limited by the speeds at which these minerals can be dissolved and CO 2 can be hydrated. To facilitate this, Columbia University is using a unique process and a combination of chemical catalysts which increase the mineral dissolution rate, and the enzymatic catalyst carbonic anhydrase which speeds up the hydration of CO 2. Carbon capture technology could prevent more than 800 million tons of CO 2 from being emitted into the atmosphere each year. Enabling cost-effective carbon capture systems could accelerate their adoption at existing power plants. If successful, Columbia University's accelerated carbon mineralization process would offer a simple way for coal plants to limit their CO 2 emissions. #### Better Enzymes for Carbon Capture. #### CO2 Capture Using Electrical Energy.
Engineered carbon mineralization emulates and accelerates natural rock weathering, whereby calcium (Ca) and magnesium (Mg) silicate minerals react with carbon dioxide dissolved in water to form calcium and magnesium carbonate minerals that are stable on geologic timescales. *Ex situ* carbon mineralization can be done with silicate rocks and even alkaline industrial byproducts.4 Calcium and magnesium are found in many other materials that are often considered the 'wastes' of industrial processes: mining wastes, steel slag, air pollution control residue, fly ash, and many other industrial wastes are abundant in magnesium and/or calcium and can be used as feedstocks for *ex situ* mineralization processes. At the Clean Energy Conversions Lab, we research carbon mineralization as a method of carbon storage in two projects: the first project loops Mg and Ca oxides that are highly reactive with CO2 to conduct direct air capture;5 the second leaches calcium and magnesium from mining wastes from carbonates.6 Our research into carbon mineralization extends beyond the lab as we consider how economics, mapping, life cycle assessments, and US policy can help deploy carbon mineralization on a broad scale.
### **1) What is Carbon Mineralization?**. Carbon mineralization is a process that naturally occurs over hundreds or thousands of years in which certain minerals inside rocks react with atmospheric CO2 to create carbonates, solid minerals that securely remove and sequester CO2. Alkaline minerals within the rock powder react with ambient CO2, trapping it in solid carbonates. A key concern with scaling up carbon mineralization above ground is the need to increase mining to access large amounts of alkaline material, as well as grinding and transport — all of which require energy. Carbon removed through surficial mineralization, for example, is challenging to account for and monitor because oceans, coasts and soils, where mine tailings and crushed rocks are spread, are open systems (as compared to a closed-system DAC plant). Carbon mineralization presents significant potential as a carbon removal approach, within a larger suite of carbon removal and climate actions, to help reach global climate goals.
For example, CO2 can be stored in concrete, known as ex-situ mineralization, in a matter of hours or injected underground for geologic carbon storage, known as in-situ mineralization, where the process occurs within a few years. Different approaches for scaling carbon mineralization include enhanced oil recovery, carbon utilization, and rock weathering, each with its own method, process, and growth opportunity. **Ex-situ:** Carbon-mineralized alternatives to traditional building materials can avoid damaging practices such as quarrying and can use hazardous waste materials from other industrial processes as inputs (e.g., fly ash or steel slag), reducing the potential for harm to local communities and the environment. For example, while in-situ mineralization methods can store carbon durably in underground rock formations, there are concerns about potential leakage at injection sites and from CO2 transportation pipelines. In the design sector, landscape architects can lower a project’s carbon footprint by specifying ‘rock dust,’ a low-cost, surficial form of carbon mineralization that can replace synthetic fertilizers, enhance soil health, and store CO2.
# Carbon Mineralization. #### Carbon Mineralization Overview:. Carbon management can be achieved by permanently storing captured carbon in natural systems or other resources via carbon mineralization processes. Natural resources for carbon mineralization which are highly reactive with CO2 include natural brines and mafic/ultramafic rocks and minerals. The Carbon Mineralization Program is dedicated to developing resource assessments for carbon management focusing on:. Projects in the Carbon Mineralization Program support the resource assessments by:. | Carbon Mineralization Project Landing Pages | |. | Resource Assessment of Industrial Wastes for CO2 Mineralization | **University of North Dakota** |. | Subsurface Carbon Mineralization Resources in Hawaiian Basalt | **University of Hawaii** |. | Resource Assessment of Geological Formations and Mine Waste for Carbon Dioxide Mineralization in the US Mid-Atlantic | **Virginia Polytechnic Institute and State University** |. | Subsurface Mafic and Ultramafic Rock Mapping and Analysis for Carbon Mineralization in the United States (Submap-CO2) | **University of Texas at Austin** |.
# Review Activation methods for enhancing CO2 mineralization via mine tailings—A critical review. Mineral carbonation has emerged as a promising solution, permanently converting carbon dioxide (CO2) into stable carbonates while simultaneously repurposing mine tailings for sustainable waste management. This review examines the chemical, mineralogical, and physical characteristics of selected tailings from nickel, asbestos, diamond, gold, iron, and platinum group metal (PGM) mines to assess their carbonation potential, and also introduces a mineral-specific analysis of mechanical activation effects across these materials. To address this, four principal activation methods are evaluated: (1) mechanical activation, which increases the surface area and number of defect sites but has limited dissolution effects; (2) chemical activation, which increases ion availability but raises concerns over reagent costs and waste disposal; (3) thermal activation, which dehydroxylates minerals at ∼650°C to increase reactivity but is energy intensive; and (4) engineered activation, which integrates multiple approaches, such as mechanochemical, thermochemical, and external-field-assisted techniques (e.g., microwaves and ultrasound), to achieve synergistic benefits.
Ex situ carbon mineralization can serve as a thermodynamically downhill strategy to capture and remove CO2 from energy and resource conversion