GIST-Columbia University, High-Efficiency CO2 Mineralization Technology Using Household Waste Proposed

[Asia Economy Honam Reporting Headquarters Reporter Lee Gwan-woo] The research team led by Professor Park Young-jun of the Department of Earth and Environmental Engineering at Gwangju Institute of Science and Technology (GIST) announced on the 28th that, through joint research with Professor Park Ah-hyung’s team at Columbia University in the United States, they proposed a highly efficient resource-recycling carbon mineralization process using organic acids generated from biomass waste.

Carbon mineralization is a technology that enables both carbon dioxide storage and utilization simultaneously. It extracts alkali metals (calcium and magnesium) contained in natural minerals or solid industrial waste and reacts them with carbon dioxide to form solid carbonates such as calcium carbonate or magnesium carbonate.

The solid carbonates produced in this way not only store the greenhouse gas carbon dioxide but can also be used as various forms of construction materials such as cement, concrete, and aggregates.

In the case of carbon mineralization using conventional inorganic acids, high solvent costs, low extraction efficiency, and difficulties in post-processing have posed challenges to securing carbon dioxide storage efficiency and process economic feasibility.

In this study, the research team applied a mixture of organic acids generated from biomass waste, which is discharged in large quantities, to the carbon mineralization process as a substitute for the existing high-cost inorganic acids, significantly improving the extraction performance of alkali metals such as calcium.

Additionally, they confirmed that various forms of rare earth metal resources contained in industrial by-products can be selectively recovered.

Biochemical wastes such as biomass (food waste, sewage waste, marine waste, etc.) form volatile organic acid compounds through anaerobic digestion processes. The formed organic acid compounds can be used as intermediates for producing fuels or petrochemical products such as plastics through alcohol and hydrocarbon synthesis.

The research team confirmed that biomass-derived organic acid compounds from biomass waste showed higher extraction efficiency for alkali metals and rare earth elements from steelmaking slag (waste discharged from the steelmaking process) compared to the widely used inorganic acids.

This phenomenon is attributed to the inductive effect of cations (ligands) that can bind with the extracted metal elements and differences in the stability constant of complexes. As the number of alkyl groups increases, the electronegativity of the ligand increases, allowing it to strongly bind with metal elements and stabilize them.

Researcher Hong Su-jin, the first author of this paper, stated, “By utilizing this technology, it is possible to effectively reduce carbon dioxide generated in industries while converting large amounts of waste into eco-friendly construction materials (cement, concrete, aggregates, etc.), thereby improving the economic feasibility of the carbon mineralization process.” She added, “In follow-up research, we expect to contribute to the 2050 carbon-neutral resource circulation economy through the development of useful resources based on carbon mineralization technology.”

This content was produced with the assistance of AI translation services.