Optimized mixed reforming of biogas with O_2 addition in spark-discharge plasma

摘要

Adding O_2 into biogas to achieve partial oxidation and CO_2 mixed reforming can not only increase H_2 + CO concentration, but also reduce energy cost for H_2 production. In this study, optimized mixed reforming of biogas with O_2 addition in spark-discharge plasma was pursued in combination with thermodynamic-equilibrium calculation. With respect to mixed reforming of biogas with O_2 addition in spark-discharge plasma, combination coefficients of independent reactions were given to quantitatively evaluate the mixed extent at various O_2/(CH_4-CO_2) ratios. Compared thermodynamic-equilibrium with experimental results, it can be concluded that the optimal O_2/(CH_4-CO_2) ratio for optimized mixed reforming of biogas in spark-discharge plasma was about 0.7. When total-carbon conversion was relatively high (>75%), H_2 + CO concentration on wet basis was the highest and energy cost for H_2 production was the lowest at O_2/(CH_4-CO_2) = 0.7, and their experimental results were closest to their thermodynamic-equilibrium values.