CO2 capture and sorbent regeneration performances of some wood ash materials. (1st January 2015)

• Record Type: Journal Article
• Authors: Guo, Yafei; Zhao, Chuanwen; Chen, Xiaoping; Li, Changhai
• Is Part Of: Applied energy. Volume 137(2015:Jan. 01)
• Page Start: 26
• Page End: 36
• Publication Date: 2015-01-01
• Subjects: CO2 capture -- Wood ash -- Low cost -- Carbonation behavior -- Regeneration performance; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2014.09.086
• Languages: English
• ISSNs: 0306-2619

Abstract

Graphical abstract: Highlights: Wood ash is tried as a new sorbent for CO2 capture from flue gas after combustion. The CO2 capture capacity of wood ash is in the range of 0.35–0.54 mmol CO2 /g. The sorbent can be completely regenerated below 200 °C. For the recycle of environmental pollutants, wood ash is a low cost CO2 sorbent. Abstract: Wood ash, which is recognized as an environmental pollutant, is tried as a new material for CO2 capture in this work. Five wood ash samples obtained from different raw materials were chosen, and an experimental demonstration of the CO2 capture performances of these wood ash samples was present in detail in a modified fixed bed reactor system. The CO2 capture and the sorbent regeneration performances of wood ash were investigated under different conditions by changing the temperature, H2 O concentration, gas flow rate and the heating rate. The CO2 capture capacities are in the range of 0.35–0.54 mmol CO2 /g for different wood ash samples under the condition of 60 °C, 10% CO2 + 12% H2 O. The CO2 capture processes contain two parts for these samples. One is the physical adsorption process, and another is the chemical reaction of K2 CO3 with CO2 and H2 O to form KHCO3, K2 CO3 ·1.5H2 O and K4 H2 (CO3 )3 ·1.5H2 O. The desired wood ash is proved to be regenerable and stable during 10-cycle CO2 sorption–desorption tests. The deactivation model and the Avrami–Erofeyev model are adopted to evaluate the CO2 sorption and desorption kinetics of this sample respectively. Considering the low cost, and the recycling of environmental pollutants, wood ash is a nice choice for CO2 capture.