A novel effective approach for synergistic NO reduction during the carbonation process by biomass-modified calcium-based sorbents

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 439; p. 135795
• Main Authors: Zhang, Menghan, Liang, Xiao, Chen, Huichao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2022
• Subjects: Biomass; Calcium-based sorbent; CO2 capture; Limestone; NO reduction; Limestone; Biomass; CO2 capture; NO reduction; Calcium-based sorbent
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.135795

[Display omitted] •Simultaneous CO2/NO removal by biomass-modified calcium-based sorbents is proposed.•CaO not only captures CO2 but also catalyzes both NO-biochar and NO-CO reaction.•Both heterogeneous and homogeneous reaction play a role in the NO reduction.•Continuously improved microstructure in L-CS ensures effectively CO2/NO removal. A novel effective method to realize the synergistic NO reduction during the carbonation step by biomass-modified calcium-based sorbents is proposed. Coconut shell, a waste from the coconut industry, and calcined limestone were used as biomass sources and calcium sources, respectively. The volatile released and the continuous pyrolysis of biochar thereafter from the biomass–modified sorbents improved the microstructure of sorbents. Biomass in the modified sorbents played an important role in NO reduction, both homogeneous and heterogeneous contributing to the reaction during the carbonation process. CaO in the sorbents showed a catalytic effect on promoting both NO-biochar and NO-CO reactions during the simultaneous CO2/NO removal process. The easy blocking of active sites by carbonation products was alleviated by sorbents modified with biomass. The continuously improved microstructure of sorbents and the exposure of active sites during the process enabled the effective CO2 capture as well as the synergic stable reduction of NO.