Electrospun Zr-Doped CaO Sorbent for CO Capture.

A Zr-doped CaO sorbent for high-temperature CO capture was fabricated using electrospinning. The nanofiber sorbent with an average filament diameter of about 160 nm is characterized by an initial CO uptake capacity of 12.1 mmol/g, a specific surface area of 79 m/g, an indentation Young's modulus of 520 MPa, and a hardness of 1.6 MPa. After 50 carbonation/decarbonation cycles, the sorbent has a decent CO uptake capacity of 9.7 mmol/g due to the uniform distribution of CaZrO in the CaO nanofibers to prevent CaO grain growth caused by CaCO sintering. It is revealed that the sorbent CO uptake capacity decreases both with an increase in the decarbonation temperature and with an increase in the CO concentration in the gas flow upon carbonation, where the sorbent CO uptake capacity is more sensitive to the decarbonation temperature than to the CO concentration in the gaseous stream during carbonation. It is assumed that the electrospun regenerable Zr-doped CaO sorbent is effective for removing CO from flue gases.