The Nanofibrous CaO Sorbent for CO2 Capture

Abstract

The nanofibrous CaO sorbent for high-temperature CO2 capture was fabricated by the calcination of electrospun composite filaments containing calcium acetylacetonate and polyacrylonitrile as a calcium-oxide precursor and a binder polymer, respectively. The calcination was carried out in air to prevent PAN carbonization and to obtain pure CaO nanofibers. The resulting mats of CaO nanofibers with the average diameter of 130 nm were characterized by a specific surface area of 31 m2/g, a CO2-uptake capacity of 16.4 mmol/g at the carbonation temperature of 618 °C, a hardness of 1.87 MPa, and the indentation Young’s modulus of 786 MPa. The low decarbonation temperature makes the fabricated sorbent promising, for example, for the calcium-looping technology of CO2 removal from the hot exhaust gases of fossil-fueled power plants.

Electrospun Zr-Doped CaO Sorbent for CO2 Capture

“…Since all nanofiber mats are prepared at a temperature of 800 °C, which is below the Tammann temperature of CaO, there is no sintering of the filaments at their cross-points or CaO particles inside the nanofibers. In addition, the obtained nanofibers completely lack decomposition products of the binder polymer and the precursor [ 25 ]. Therefore, the bond between CaO grains inside nanofibers is due only to Van der Waals forces, which provide the free movement of CaO grains inside them.…”

“…The carbonation/decarbonation cycle was repeated 50 times. The carbonation and decarbonation temperatures were the same as in [ 25 ]. The CO 2 uptake capacity of the nanofibrous sorbents was determined by the amount of captured CO 2 divided by the sample weight before carbonation.…”

“…The third is to combine it with other chemical and physical methods to further convert electrospun filaments to functional nanofibers [ 23 , 24 ]. The fabrication of CaO nanofibers via the heat treatment of electrospun composite filaments containing an oxide precursor and a polymer, carried out in our previous work, is a fine example of the third direction [ 25 ].…”