Thermodynamics and kinetics analysis from liquid chemical looping gasification of lignin with bismuth-based oxygen carrier

Abstract

Liquid chemical looping gasification (LCLG) provides a new direction for fuel gasification, which can avoid the technical challenges brought by using solid OCs, such as acting and coking. But the related research ideas and data are few. Here, we have conducted relevant research. Thermodynamics and kinetics analysis of lignin (LG) with bismuth oxide (Bi2O3) during LCLG were investigated. Through thermodynamic analysis, the optimal temperature for LCLG was 800– 850 °C, and the optimal mixing mass ratio of Bi2O3/LG was about 5.00– 6.00. The effects of heating rate and oxygen carrier mass ratio on apparent activation energies were carried out by thermogravimetric analyzer combined with on-line mass spectrometry. The apparent activation energies of lignin samples were 151.333,171.572,199.826, and 127.012 kJ·mol−1. The activation energy of the main gas products was obtained by the isoconversion method. In the LCLG process, with the increase of Bi2O3 mixing ratio, the activation energy of CO, CO2, and H2 formation first increased and then decreased, wherein that of H2 (59.89 kJ·mol−1) was on the peak. The results are conducive to the development of new liquid oxygen carriers and also provide data basis for the multi-way utilization of carbon-based fuels.