title: Evolution of char structure during steam gasification of the chars produced from rapid pyrolysis of rice husk.
abstract: The structural evolution of rice husk char particles during steam gasification was studied by ultimate analysis, inductively coupled plasma atomic emission spectroscopy, scanning electronic microscope, N(2) physisorption method and X-ray diffraction. Drastic changes in char structure occurred even when the char conversion was minimal. The C, H and O content decreased by more than 85%, 67% and 91%, respectively. The H/C atomic ratio always increased, while the O/C exhibited a "∼" shape. The maximum porosity appeared at char conversion of 48.6%. D(s) and d(ave) showed a good linear relationship. Aliphatic structures and smaller aromatic rings tended to be preferentially consumed to left the char more ordered and enriched with larger aromatic ring systems. The presence of steam favored the volatilization of Na. K, Mg and Ca showed a similar behavior and their concentrations reached maxima at 60.3%. Great loss of O-containing structures caused significant volatilization of K, Mg and Ca.
authors.affiliation: State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China. fupengsklcc@gmail.com
authors.forename: Peng
authors.initials: P
authors.lastname: Fu
authors.forename: Song
authors.initials: S
authors.lastname: Hu
authors.forename: Jun
authors.initials: J
authors.lastname: Xiang
authors.forename: Weiming
authors.initials: W
authors.lastname: Yi
authors.forename: Xueyuan
authors.initials: X
authors.lastname: Bai
authors.forename: Lushi
authors.initials: L
authors.lastname: Sun
authors.forename: Sheng
authors.initials: S
authors.lastname: Su
mesh_terms: D002606:Charcoal / Q000032:analysis* / Q000138:chemical synthesis*; D005740:Gases / Q000737:chemistry*; D017745:Incineration / Q000379:methods*; D012275:Oryza / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D013227:Steam
chemical_list: D005740:Gases; D013227:Steam; C540010:biochar; D002606:Charcoal