Li4SiO4 adsorbent derived from industrial biomass fly ash for high-temperature CO2 capture

Abstract

In recent years, biomass derived Li4SiO4 adsorbent has attracted increasing attentions in the field of post-combustion high-temperature CO2 capture. In this work, for the first time, industrial fly ash collected from the biomass boiler was employed to produce Li4SiO4 adsorbent. In addition, ash pretreatment methods including water-washing and acid-washing were also carried out to promote the performance of derived adsorbent. By evaluating the physicochemical properties as well as the CO2 capture capacity of these adsorbents, it is concluded that the industrial biomass fly ash is feasible for the production of Li4SiO4 with a reasonable CO2 adsorption capacity of ∼0.243 g/g. It is further found that the acid-washing could remove the majority of impurities inside fly ash and increase the purity of derived adsorbent, resulting in a superior capacity as high as ∼0.358 g/g. However, in comparison with lab-scale obtained biomass ash, the industrial biomass fly ash contains more water-insoluble impurities, and thus the secondary element removal effects of water-washing pretreatment were significantly inhibited. The above findings could provide guidance for the future scale-up production of biomass derived Li4SiO4 adsorbents for practical carbon capture applications.