Energy Conversion and Management, Vol.151, 457-464, 2017
High quality syngas production from catalytic gasification of woodchip char
This work aims on the production of high quality syngas suitable for widely applications from catalytic woodchip char gasification in a lab-scale fixed bed reactor. Using the absorption of the char to load catalysts was conducted in this study. The results showed that the char conversion and hydrogen yield were increased significantly after impregnation with potassium salts. The catalytic activity of the four catalysts is in the order: K2CO3 approximate to KOH > CH3COOK > KCI. In addition, when 6 wt% of KOH solution was used to impregnate, the maximum hydrogen yield of 197.2 g/kg char can be obtained, but further increasing the mass fraction of impregnation solution had an adverse impact on hydrogen yield and H-2/CO. Moreover, the influence of particle size, reaction temperature and gasifying agent were investigated. The particle size of the char had little effect on gasification characteristics. Increasing temperature and steam amount were beneficial to improve char conversion and hydrogen yield, and the high quality syngas (H-2 + CO) with the ratio of 91.8% was obtained at 950 degrees C while the ratio of H-2/CO decreased from 3.7 to 1.65 with increasing temperature. Additionally, continuously increasing steam had little influence on gasification consequences and was poor in economy. Introducing oxygen can improve the char conversion and adjusted the ratio of H-2/CO in an economical way, but higher ER would weaken the quality of syngas.