Engineered yeast for enhanced CO mineralization.

In this work, a biologically catalyzed CO mineralization process for the capture of CO from point sources was designed, constructed at a laboratory scale, and, using standard chemical process scale-up protocols, was modeled and evaluated at an industrial scale. A yeast display system in was used to screen several carbonic anhydrase isoforms and mineralization peptides for their impact on CO hydration, CaCO mineralization, and particle settling rate. Enhanced rates for each of these steps in the CaCO mineralization process were confirmed using quantitative techniques in lab-scale measurements. The effect of these enhanced rates on the CO capture cost in an industrial scale CO mineralization process using coal fly ash as the CaO source was evaluated. The model predicts a process using bCA2- yeast and fly ash is ~10% more cost effective per ton of CO captured than a process with no biological molecules, a savings not realized by wild-type yeast and high-temperature stable recombinant CA2 alone or in combination. The levelized cost of electricity for a power plant using this process was calculated and scenarios in which this process compares favorably to CO capture by MEA absorption process are presented.