Utilization of biomass to promote calcium‐based sorbents for CO₂capture

Abstract

To promote and maintain the reactivity of calcium-based sorbents for CO 2 capture is essential for calcium looping technology. Biomass together with cement was doped with calcium-based sorbents pellets to promote the reactivity and enhance the sintering resistance for CO 2 capture. The influence of parameters, such as biomass types, addition, pretreatments, precursors, and cement amounts on CO 2 capture performance of sorbents are determined and an optimized process is developed for sorbents pellets making. Biomass such as coconut shell doped with calcium-based sorbents present promising enhancement in CO 2 capture capacity. Sorbents doped with pretreated biomass exhibit excellent CO 2 capture performance with a carbonation conversion of 0.6 and 0.73 after 10 cycles, respectively. The microstructures of the sorbents characterized by N 2 physisorption/desorption and the phase structure determined by in situ X-ray diffraction (XRD) are investigated as a supplement for mechanism study. The release of volatiles and pyrolysis of biomass char in sorbents are the main causes for microstructure improvement for sorbents. The formations of CaAl 2 O 4 , CaAl 4 O 7 and Ca 12 Al 14 O 33 in sorbents during the carbonation/calcination cycles account for the enhancement of the sorbents' sintering resistance.

Review on the modifications of natural and industrial waste CaO based sorbent of calcium looping with enhanced CO2 capture capacity

“…Consequently, researchers exerted great effort to overcome this degradation and reported their studies in articles and journals since 1999 because sorbent degradation causes high operating costs, low CO 2 capture capacity, and low stability of the CaO sorbent, thus increasing the replenishment of sorbents. The most recent improvement involves binary reinforcement where two inert materials were combined together with CaO sorbent [ 31 ], nano CaO [ 32 ], and biomass and cement doped with calcium-based sorbents [ 33 ].…”