ABSTRACT
The separation of valuable chemicals from raw products, where a great number of chemicals coexist, is the key technology in biomass refinery. In this study, the applicability of membrane separation of valuable chemicals from our currently developed portable superheated steam (SHS) biomass pyrolysis process was demonstrated. Phenols (phenol, p-cresol, guaiacol, methyl guaiacol, and ethyl guaiacol), furfural, and acetone were successfully separated by pervaporation using the silicone rubber membrane from model solutions and an actual SHS derived aqueous solution. The solution was also concentrated effectively by reverse osmosis separation using a polyamide membrane. When a high concentration of SHS solution was fed to the pervaporation process, a phase-separated permeate was obtained, which indicated that the reverse osmosis concentration combined with pervaporation separation is useful for the superheated steam process.
Subject(s)
Chemical Fractionation/methods , Furaldehyde/isolation & purification , Hot Temperature , Membranes, Artificial , Phenols/isolation & purification , Acetone/chemistry , Acetone/isolation & purification , Biomass , Chemical Fractionation/instrumentation , Furaldehyde/chemistry , Osmosis , Phenols/chemistry , Solutions/chemistry , SteamABSTRACT
To develop a novel noncatalytic biomass refinery process that can be used as a portable process, superheated steam pyrolysis was investigated to produce both carbonized solid fuels and chemicals using a large-scale reactor. Individual biomass components and native biomass (Sugi, Japanese cedar) were pyrolyzed. Between 150 and 400 degrees C, the vaporizing fractions of cellulose, xylan, and kraft lignin were summarized using a numerical model. Cellulose was converted to glycolaldehyde, furfural, 5-hydroxymethyl furfural and levoglucosan, whereas xylan was converted to glycolaldehyde, furfural, and acetic acid. Kraft lignin produced a slight yield of phenol and guaiacol. The total vaporization fraction of Sugi and its vaporizing rate were explained sufficiently using a numerical model based on the weighted average of the vaporizing properties of the individual components. However, the yields of phenol, guaiacol, and acetic acid were underestimated, while the yields of furfurals and levoglucosan were overestimated. Possible synergetic effects among chemicals in the superheated steam pyrolysis of native biomass were also discussed.
