Controlling the reaction microenvironments through an embedding strategy to strengthen the chemical looping reforming of methane based on decoupling process

Abstract

Aiming at the complexity of traditional biomass gasification technology with low conversion efficiency and high tar content and realizing the directional conversion of biomass into syngas, this paper proposed a new decoupling process of biomass pyrolysis and chemical looping reforming of volatile components. Designing a high activity and selective oxygen carrier is the key to the chemical looping reforming process. This study used an embedding strategy to develop the oxygen carrier. NiFe2O4 was embedded in SBA-15 to control the reaction microenvironment. The reaction performance of NiFe2O4@SBA-15 under different conditions was investigated via a combination of fixed-bed reactor and on-line mass spectrometry. The results showed that the CO selectivity was close to 100%. The CH4 conversion and CO selectivity of NiFe2O4@SBA-15 were increased by 121.29% and 114.40% than NiFe2O4, respectively. The optimal embedding ratio (20%) and reaction temperature (900 °C) were determined during the experiment, which was consistent with the thermodynamic simulation results. The gas–solid reaction model was used to solve the reaction kinetics of the oxygen carrier, and the activation energy was 118.23 kJ·mol−1. This study gives a research basis for screening oxygen carrier and the design of reactor in the directional conversion of biomass pyrolysis full volatiles into syngas via chemical looping reforming.