Multi-function of oxygen carrier for in-situ tar removal in chemical looping gasification: Naphthalene as a model compound. (1st November 2019)

• Record Type: Journal Article
• Authors: Zeng, Jimin; Hu, Jiawei; Qiu, Yu; Zhang, Shuai; Zeng, Dewang; Xiao, Rui
• Is Part Of: Applied energy. Volume 253(2019)
• Publication Date: 2019-11-01
• Subjects: Oxygen carrier -- In-situ tar removal -- Chemical looping gasification -- Naphthalene; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2019.113502
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: In-situ tar removal during chemical looping gasification was studied. Multi-functional oxygen carrier for tar conversion was investigated. Reaction route for the tar removal used by the oxygen carrier was proposed. Abstract: Investigating the multi-functions of the oxygen carrier (OC) on in-situ tar conversion during chemical looping gasification (CLG) is crucial for the improvement of the syngas quality and the efficiency of the operation. In this paper, the tar reactions during the CLG process caused by three different OCs (iron oxide, nickel oxide, and copper oxide) was studied using naphthalene as a model compound. The functions of the metal and the lattice oxygen for the conversion were discussed, respectively. The stoichiometric ratio between the OC and the tar was identified. The reaction route and the oxygen transfer during the process was proposed. The results showed that the tar conversion on the metal-phase OC was 40–50%, while the conversion was over 90% with sufficient lattice oxygen. Reduced OCs led to a typical product composition: 18.49% CO2, 35.84% CO, and 45.67% char. There were at most two different phases of the OC after the reactions, for instance, Fe and FeO, FeO and Fe3 O4, Fe3 O4 and Fe2 O3 . The char composition for three reduced points (A06, A08, and A10) was 44.20%, 45.67%, and 46.19%, respectively. The result improved the reacting understandings of in-situ tar removal during the CLG process.