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On the basis of the Gibbs free energy minimization principle, the dry autothermal reforming performance of crude glycerol in situ hydrogen separation is investigated via thermodynamic analysis. The impact of hydrogen separation fraction on gas composition in product, carbon formation and reaction heat is studied. It can be found that the hydrogen separation promotes the hydrogen production and hinders methane formation. The hydrogen removal is selective to the reduction of carbon deposition, which improves the carbon formation at a low feed CO 2 to glycerol molar ratio and the impact is reverse for high feed CO 2 to glycerol molar ratio. When the reaction temperature varies from 850 K to 900 K, the required oxygen to glycerol molar ratio of thermal neutral condition is obviously increased from 0.15 to 0.4 with hydrogen removal. Meanwhile, the glycerol impurities evaluation indicates that the syngas yield is significantly reduced with the increase of the glycerol impurities. At a high temperature, the hydrogen removal is in favor of the achievement of autothermal process.

The performance of glycerol autothermal reforming in membrane reactors with in situ hydrogen separation is investigated by means of thermodynamic analysis based on Gibbs free energy minimization method. The influence of operational parameters such as reaction temperatures and oxygen to glycerol ratios under different hydrogen separation fractions is evaluated. It is found that reaction temperatures have a more significant impact on hydrogen yield compared to other parameters. The hydrogen removal can promote the hydrogen production obviously and reduce the required temperature of the maximum hydrogen yield. The hydrogen separation effect on carbon formation is discussed. Meanwhile, the performance of ethanol–glycerol mixture autothermal reforming process is also analyzed.

Glycerol reforming technology provides an efficient means for the hydrogen production industry and the utilization of biodiesel-derived crude glycerol. Fluidized bed reactors have potential in interphase mass/heat transfer and mitigating catalyst deactivation. In this study, computational fluid dynamics is used to investigate the performance of glycerol steam reforming in a fluidized bed system. A bubble-structure-dependent drag model is implemented into the two-fluid model to reflect the bubble effect. A three-dimensional simulation is conducted. The model is verified by experimental data. By analysis of the influence of operating conditions and property parameters, it is found that the reaction temperature plays a vital role in the enhancement of hydrogen production.

The steam absorption process in a fluidized bed of binary mixture is investigated to study the mass transfer performance of active particles surrounding inert particles by means of CFD approaches. A bubble-based drag model is incorporated to the multi-fluid model to account for the bubble effect on mixing and segregation behaviors of binary mixture in a fluidized bed system. The predictions using different drag models are compared with experimental results. The effect of mixing and segregation behaviors of inert particles and active particles on mass transfer performance is evaluated. The sensitivity of mass transfer process to operating conditions is also analyzed. The results reveal that the bubble-based drag model can give a better prediction with measured data. The enhancement of mixing degree of inert particles and active particles can promote the mass transfer performance.