Effect of Different Activation Processes on CaO/Fly Ash Mixture for CO₂ Capture

Abstract

CO 2 capture at high temperature through calcium looping is a capable technology for the implementation of carbon capture and storage. The major drawback of this process is the rapid deactivation of calcium-based sorbent due to sintering and attrition. To reduce these drawbacks, an environmentally friendly and low-cost approach is highly appreciated by researchers. Efforts were made to introduce a cost-effective and eco-friendly method to reduce sintering and enhance capacity by adding fly ash from coal-fired plants, into Ca-based sorbents with acetic acid through sonochemical and ball milling methods. Four different methods of mixing were used, i.e., dry, wet, sonochemical, and ball milling methods. The sorbents were characterized by SEM-EDS, XRD, TGA, and XRF. Hydration under acidic conditions with Ca-based sorbent using fly ash showed improved capacity and stability rather than under basic conditions. The sonochemical method achieved the highest CaO conversion of 100% in the first two cycles followed by the ball milling method with 99.8% also maintaining stability through the cycles as compared to other methods. The ball milling method achieved higher improvement to not only proper mixing of fly ash and CaO but also a reduction in sizes improved conversion and stability, and thus it can be considered as a green technology for scaled-up CO 2 capture.

Advanced Strategies in Metal‐Organic Frameworks for CO2 Capture and Separation

“…In another perspective, geological storage for enhanced oil and coal bed methane recovery is also possible. However, due to its chemical properties, separation and capture are becoming problematic to the industry [19,20] . So far, numerous gas separation technologies have been investigated to capture CO 2, i.e.…”

“…However, due to its chemical properties, separation and capture are becoming problematic to the industry. [19,20] So far, numerous gas separation technologies have been investigated to capture CO 2, i.e. absorption, adsorption, hydrated-based system, cryogenic distillation, and membrane separation.…”

Blending Wastes of Marble Powder and Dolomite Sorbents for Calcium-Looping CO2 Capture under Realistic Industrial Calcination Conditions

“…Due to environmental issues, several solid CaO sorbents recovered from waste resources have been tested in the CaL process: WMP [ 15 , 26 , 27 ], carbide slag [ 28 , 29 ], blast furnace [ 30 ], eggshells, shellfish shells and cuttlefish bones [ 27 , 31 , 32 , 33 , 34 , 35 ] and paper and pulp industry sludge [ 36 ]. Additionally, to improve the sorbents’ stability and reactivity along the cycles, some wastes were also tested as supports or doping materials: bottom and fly ash [ 36 , 37 , 38 , 39 , 40 , 41 , 42 ], biomass ash [ 41 ], industrial sludge [ 42 ], spent blenching clay [ 43 ] and spent fluid catalytic cracking catalyst (FCC) [ 36 ]. Among the CaCO 3 -based wastes already proposed for CO 2 capture, the WMP composed mainly of CaCO 3 and vestigial amounts of other elements (Mg, Si, Al, Fe, etc.)…”

Density Functional Theory Study on CO2 Adsorption by Ce-Promoted CaO in the Presence of Steam

“…The growing anthropogenic CO 2 emissions, mainly derived from fossil fuel combustion in power plants, have been aggravating global warming, which leads to an uncertain future . CO 2 capture and storage is considered as a promising method for reducing CO 2 emissions, especially from coal-fired power plants, which are the main sources of anthropogenic CO 2 . − The calcium looping (CaL) process is deemed as one of the most effective technologies for CO 2 capture, which takes advantages of the abundant distribution of raw materials and the low cost and efficient integration with fossil fuel power plants. , On the basis of a reversible reaction, as shown in eq , the CaL process involves a carbonation reaction of CaO and a calcination reaction of CaCO 3 ; thus, the CaL process is implemented with the repetitive carbonation/calcination cycles However, the major drawback of the CaL process is the sharp decay in the CO 2 capture capacity of CaO with the number of cycles, which is as a result of sintering from a high temperature during the calcination process .…”

“…6,7 On the basis of a reversible reaction, as shown in eq 1, the CaL process involves a carbonation reaction of CaO and a calcination reaction of CaCO 3 ; thus, the CaL process is implemented with the repetitive carbonation/calcination cycles. 8 + ↔ CaO CO CaCO (1)…”