High performance of self-regulating temperature solid amine hollow fibers for direct air capture of CO2

In gas separation processes, magnetic induction heating (MIH) offers a promising alternative to conventional heating by avoiding its poor energy efficiency. In this paper, we report a CO 2 sorbent comprised of magnetic nanoparticles (MNPs), hollow fiber, and solid amine for efficient direct air capture (DAC) of CO 2 . The MNPs have the nature of temperature controlling, which making the composite hollow fibers have self-regulating temperature properties. Furthermore, the maximum temperature of composite hollow fiber can be tuned by varying the MNPs content. The heating rate and cooling rate of the composite hollow fibers were compared with those of conventional heating method. The results showed that the magnetic nanoparticles composited hollow fibers exhibited higher heating rate and cooling rate. For the self-regulating temperature solid amine hollow fibers, the magnetic nanoparticle content has effects on CO 2 adsorption capacity, desorption rate and cooling rate. Increasing the magnetic nanoparticles content led to a trade-off effect between heating rate and CO 2 adsorption capacity. The CO 2 adsorption capacity decreased whereas the heating rate increased. The advantage of induction heating over conventional heating for regenerating the CO 2 sorbent were demonstrated. Specifically, the PEI-ECH-MNP20%-PAN HFs achieved heating rate, cooling rate, and desorption rates of 6.7 ℃ min −1 , 3.8 ℃ min −1 , and 0.11 mmol CO 2 g −1 min −1 , respectively. The induction heating method yielded a higher heating rate, cooling rate and desorption rate than conventional heating, which is expected to significantly shorten the cycle time, and thus improve the overall efficiency of the CO 2 capture system. For direct air capture, PEI-ECH-MNP20%-PAN HFs exhibit a CO 2 adsorption capacity of 2.59 mmol g −1 , and saturated PEI-ECH-MNP20%-PAN HFs can be efficiently regenerated via a magnetic induction heating-vacuum swing (MIH-VS) desorption process.