Engineered yeast for enhanced CO₂ mineralization

Area of Science:

• Biotechnology
• Chemical Engineering
• Environmental Science

Background:

• Carbon dioxide (CO2) capture from point sources is crucial for mitigating climate change.
• Biological catalysts offer potential for enhancing CO2 mineralization efficiency.
• Industrial-scale application of biological CO2 capture requires cost-effective and scalable solutions.

Purpose of the Study:

• To design, construct, and evaluate a biologically catalyzed CO2 mineralization process at laboratory and industrial scales.
• To screen and optimize biological components for enhanced CO2 hydration and calcium carbonate (CaCO3) mineralization.
• To assess the economic viability of the developed process compared to existing CO2 capture technologies.

Main Methods:

• Utilized a yeast display system in Saccharomyces cerevisiae for screening carbonic anhydrase isoforms and mineralization peptides.
• Quantitatively measured enhanced rates of CO2 hydration, CaCO3 mineralization, and particle settling.
• Modeled and evaluated the industrial-scale CO2 capture cost using coal fly ash as the CaO source.

Main Results:

• Identified specific carbonic anhydrase and peptide combinations that significantly enhanced CO2 mineralization steps.
• A process using bCA2-yeast and fly ash demonstrated a ~10% cost advantage per ton of CO2 captured compared to non-biological processes.
• Calculated levelized cost of electricity for power plants incorporating this CO2 capture technology.

Conclusions:

• Biologically enhanced CO2 mineralization offers a cost-effective solution for CO2 capture from point sources.
• The developed process shows potential for competing with established methods like MEA absorption.
• Further scale-up and integration into power generation are feasible and economically promising.