Analysis of lignocellulose and microcrystalline cellulose densification in the powder bed during gas pressurization

High-pressure gasification of fiber powders is an effective way to produce syngas. Since fiber powders are elastic materials, conveying and discharging under pressurized environment is challenging. In this paper, the compression process of lignocellulose and microcrystalline cellulose under gas pressurization was experimentally studied and the difference of compression behavior was systematically compared. The results showed that particle shape and surface roughness were important factors leading to the high compressibility of the lignocellulose powder bed. The irregular shape and the ductility of filamentous fibers caused the large void fraction of lignocellulose. The compression effect of gas penetration on lignocellulose was higher than that of microcrystalline cellulose. Furthermore, the small surface roughness weakened the difficulty of the relative movement between lignocellulose particles, making the packing state easy to change. The rebound behavior of the lignocellulose bed illustrated the existence of elastic deformation and extended the understanding of compression mechanisms with gas pressurization. The release coefficient of the bed was positively correlated with the degree of densification during the pressurization process.