Chemical looping reforming of toluene via Fe2O3@SBA-15 based on controlling reaction microenvironments

Chemical looping technology is one of the most promising approaches in the fields of fuel conversion, pollution removal, energy conservation, and carbon dioxide capture and utilization and has been extensively investigated for more than two decades. A majority of the chemical looping process is achieved through the migration and transformation of lattice oxygen. Thus, exploring the migration and transformation of lattice oxygen is critical to clarify chemical looping’s reaction rules to allow for further control of reaction selectivity and yield. Herein, recent advances in the exploration of lattice oxygen’s migration mechanism are systematically reviewed, with a focus on structure–activity relationships. The great roles that characterization techniques perform to address the challenges in exploring the migration mechanism of lattice oxygen activities are discussed first. We then outline the categories of oxygen carrier materials and the migration mechanism of lattice oxygen. Lastly, the most promising research directions that design high-performance oxygen carriers with well-regulated lattice oxygen activity through the redox reaction mechanism are overviewed. We infer that the research on the relationship between lattice oxygen activity and target products is challenging but essentialit is a direction worthy of our efforts in the future.

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Section: Design Of Ocmentioning

confidence: 99%

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Song

Lin

et al. 2023

Energy Fuels

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“…6,7 A decoupling-based strategy for the chemical looping reforming (CLR) biomass pyrolysis and volatile fraction has been proposed. 7,8 The volatile fraction of biomass could be partial oxidized to hydrogen-rich syngas in the reformer reactor by oxygen carriers (OCs), enabling efficient conversion of biomass. The species of biomass pyrolysis volatiles were diverse, and large molecular components such as aromatic compounds, phenols, acids, and aldehydes could account for 60%−70% of the specimen.…”

Section: ■ Introductionmentioning

confidence: 99%

“…The analysis of the liquid products was quantitatively determined by the internal standard (dodecane).The baseline of toluene could be found from the previous research. 8 Data Analysis Methods. Toluene's conversion of (x, %) is expressed by the ratio of the mass of toluene reacted in the reaction time to the total mass of toluene drummed and was calculated by eq 1: 17,38 (1) where m t is the total mass of introduced toluene and m t ′ is the mass of consumed toluene.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Based on the Tuinstra and Koenig law, the disorder degree of carbon deposition was quantified by using crystallite plane size (L a ). 40 L a is calculated as shown in eq 8: (8) where L a is the microcrystalline plane size, and I G and I D are the G-and D-peak intensities, respectively. Kinetic Analysis Method.…”

Section: ■ Introductionmentioning

confidence: 99%

“…31 Studies have shown that using SBA-15 encapsulated OCs was feasible for CLR technology. 7,8 Therefore, this paper proposes a strategy of SBA-15 encapsulating nanoperovskite OCs to improve the reaction performance.…”

Section: ■ Introductionmentioning

confidence: 99%

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Chemical Looping Reforming of Toluene as Volatile Model Compound over LaFe_xM_1–xO₃@SBA via Encapsulation Strategy

Sun

Zhang

et al. 2023

Ind. Eng. Chem. Res.

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Aiming at the problems of large tar influence and low gasification efficiency in traditional biomass gasification, in this paper, a chemical looping reforming (CLR) of volatiles from biomass pyrolysis based on decoupling strategy is proposed to convert macromolecular volatiles into hydrogen-rich syngas. A series of highly active and selective oxygen carrier (OC) SBA-15 encapsulating LaFe x M1–x O3 (M = Ni, Cu, Co) for the biomass CLR process was developed. Reaction kinetics and cycling performance of toluene CLR process on LaFe0.6Co0.4O3@SBA-15 OCs were explored. Experimental results showed that the encapsulation effect gave the metal oxide a better dispersion, reduced the sintering, and improved the reaction performance. Compared with LaFeO3, the toluene conversion increased from 52.3% to 79.7%, the CO selectivity improved from 57.0% to 87.4%, and the oxygen release (OR) increased by 100% after encapsulation in SBA-15. Due to the substitution of Ni2+, Cu2+ and Co2+ on Fe3+, more oxygen vacancies in OCs were created, and both conversions of toluene and selectivity of CO were improved. Among them, the incorporation of Co had the best performance, the toluene conversion was 81.6%, and the CO selectivity was 96.8%. The kinetics of the LaFe0.6Co0.4O3@SBA-15 reaction was solved using a gas–solid reaction model with an activation energy of 103.9 kJ mol–1 and a pre-exponential factor of 123.8 s–1. The performance of LaFe0.6Co0.4O3@SBA-15 was tested for 10 cycles, and it was found that conversion of toluene and CO selectivity were well-maintained at 90.0%–92.0% and 93.0%–96.0%, respectively. This study could guide the selection of OCs in reforming macromolecular volatiles from biomass pyrolysis to produce hydrogen-rich syngas.

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Chemical looping reforming of the micromolecular component from biomass pyrolysis via Fe2O3@SBA-16

Li,

Zhang,

Yang

et al. 2024

Int J Coal Sci Technol

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To solve the problems of low gasification efficiency and high tar content caused by solid–solid contact between biomass and oxygen carrier in traditional biomass chemical looping gasification process. The decoupling strategy was adopted to decouple the biomass gasification process, and the composite oxygen carrier was prepared by embedding Fe2O3 in molecular sieve SBA-16 for the chemical looping reforming process of pyrolysis micromolecular model compound methane, which was expected to realize the directional reforming of pyrolysis volatiles to prepare hydrogen-rich syngas. Thermodynamic analysis of the reaction system was carried out based on the Gibbs free energy minimization method, and the reforming performance was evaluated by a fixed bed reactor, and the kinetic parameters were solved based on the gas–solid reaction model. Thermodynamic analysis verified the feasibility of the reaction and provided theoretical guidance for experimental design. The experimental results showed that the reaction performance of Fe2O3@SBA-16 was compared with that of pure Fe2O3 and Fe2O3@SBA-15, and the syngas yield was increased by 55.3% and 20.7% respectively, and it had good cycle stability. Kinetic analysis showed that the kinetic model changed from three-dimensional diffusion to first-order reaction with the increase of temperature. The activation energy was 192.79 kJ/mol by fitting. This paper provides basic data for the directional preparation of hydrogen-rich syngas from biomass and the design of oxygen carriers for pyrolysis of all-component chemical looping reforming.

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Chemical looping reforming of toluene via Fe2O3@SBA-15 based on controlling reaction microenvironments

Cited by 20 publications

References 37 publications

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Chemical Looping Reforming of Toluene as Volatile Model Compound over LaFe_xM_1–xO₃@SBA via Encapsulation Strategy

Chemical looping reforming of the micromolecular component from biomass pyrolysis via Fe2O3@SBA-16

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Chemical looping reforming of toluene via Fe2O3@SBA-15 based on controlling reaction microenvironments

Cited by 20 publications

References 37 publications

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Chemical Looping Reforming of Toluene as Volatile Model Compound over LaFexM1–xO3@SBA via Encapsulation Strategy

Chemical looping reforming of the micromolecular component from biomass pyrolysis via Fe2O3@SBA-16

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Chemical Looping Reforming of Toluene as Volatile Model Compound over LaFe_xM_1–xO₃@SBA via Encapsulation Strategy