Probing Synergies between Lignin-Rich and Cellulose Compounds for Gasification

• Main Authors: Martin J. Taylor, Apostolos K. Michopoulos, Anastasia A. Zabaniotou, Vasiliki Skoulou
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: Energies
• Subjects: gasification; lignocellulosic biomass waste; lignin; cellulose; Na promotion; water gas shift
• Online Access: https://www.mdpi.com/1996-1073/13/10/2590

The fixed-bed gasification of lignin-rich and -deficient mixtures was carried out to probe the synergistic effects between two model compounds, Lignin Pink (LP) rich in Na and Cellulose Microcrystalline (CM). Reaction conditions utilized the most commonly used air ratios in current wood gasifiers at 750 and 850 °C. It was found that by increasing the lignin content in the mixture, there was a selectivity change from solid to gas products, contrary to a similar study previously carried out for pyrolysis. This change in product mix was promoted by the catalytic effect of Na edge recession deposits on the surface of the char. As a result, the water gas shift reaction was enhanced at 850 °C for the LP₄₈CM₅₂ mixture across all air ratios. This was evidenced by a strong correlation between the produced H₂ and CO_x. Meanwhile, by lowering the lignin content in the mixtures, the reactivity of cellulose microcrystalline was found to generate more char at higher temperatures, similar to lignin mixtures when undergoing pyrolysis.