Abstract
Calcium looping is a promising technology to capture CO2 from the process of coal-fired power generation and gasification of coal/biomass for hydrogen production. The decay of CO2 capture activities of calcium-based sorbents is one of the main problems holding back the development of the technology. Taking carbide slag as a main raw material and Ca12Al14O33 as a support, highly active CO2 sorbents were prepared using the hydrothermal template method in this work. The effects of support ratio, cycle number, and reaction conditions were evaluated. The results show that Ca12Al14O33 generated effectively improves the cyclic stability of CO2 capture by synthetic sorbents. When the Al2O3 addition is 5%, or the Ca12Al14O33 content is 10%, the synthetic sorbent possesses the highest cyclic CO2 capture performance. Under harsh calcination conditions, the CO2 capture capacity of the synthetic sorbent after 30 cycles is 0.29 g/g, which is 80% higher than that of carbide slag. The superiority of the synthetic sorbent on the CO2 capture kinetics mainly reflects at the diffusion-controlled stage. The cumulative pore volume of the synthetic sorbent within the range of 10–100 nm is 2.4 times as high as that of calcined carbide slag. The structure of the synthetic sorbent reduces the CO2 diffusion resistance, and thus leads to better CO2 capture performance and reaction rate.
Highlights
With the frequent occurrence of various extreme climates around the world and the increasingly intensified global climate change caused by greenhouse gases, a global consensus has been reached to reduce greenhouse gas emissions [1,2,3]
Calcium looping (CaL) process is one of the feasible large-scale CO2 capture technologies at present, which is applicable to the process of coal-fired power generation and gasification of coal/biomass for hydrogen production [5,6,7,8,9]
The sorbent doped with 15 wt.% attapulgite displayed better CO2 capture performance than limestone by an increase of 128% after 20 cycles under the same condition
Summary
With the frequent occurrence of various extreme climates around the world and the increasingly intensified global climate change caused by greenhouse gases, a global consensus has been reached to reduce greenhouse gas emissions [1,2,3]. Energies 2019, 12, 2617 at optimizing CaO-based sorbents to maintain good CO2 absorption activity and anti-sintering performance in the cyclic process, and obtaining a high CO2 capture efficiency. These methods include hydration [13,14], thermal pre-treatment [15,16], use of porous CaO-based precursors [17,18], and doping [19,20,21,22]. CaO-based, calcium aluminates-stabilized sorbents have gained increasing interest owing to their advantages such as wide material sources, good sintering resistance, and high cyclic CO2 capture capacity. Morphological characterizations were used to explain the relationship between the micro pore structure and the performance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
