A simple expression for the apparent reaction rate of large wood char gasification with steam

• Published in: Bioresource technology Vol. 101; no. 11; pp. 4187 - 4192
• Main Authors: Umeki, Kentaro, Roh, Seon-ah, Min, Tai-jin, Namioka, Tomoaki, Yoshikawa, Kunio
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.06.2010; [New York, NY]: Elsevier Ltd; Elsevier
• Subjects: Agricultural engineering; Apparent reaction rate; Area technology; Areell teknik; Bioengineering; Biological and medical sciences; biomass; Biomass gasification; Bioteknik; Char gasification with steam; Effective factor; FORESTRY, AGRICULTURAL SCIENCES and LANDSCAPE PLANNING; Fundamental and applied biological sciences. Psychology; Gases; gasification; hydrogen production; Jordbruksteknik; Kinetics; SKOGS- och JORDBRUKSVETENSKAP samt LANDSKAPSPLANERING; Steam; TECHNOLOGY; TEKNIKVETENSKAP; Wood; Biomass gasification; Effective factor; Char gasification with steam; Apparent reaction rate; PDEs; LCR; SEM; OCR; Carbonization; Wood; Gasification; Biomass; Water vapor; Reaction rate
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2010.01.051

A simple expression for the apparent reaction rate of large wood char gasification with steam is proposed. Large char samples were gasified under steam atmosphere using a thermo-balance reactor. The apparent reaction rate was expressed as the product of the intrinsic rate and the effective factor. The effective factor was modified to include the effect of change in char diameter and intrinsic reaction rate during the reaction. Assuming uniform conversion ratio throughout a particle, the simplified reaction scheme was divided into three stages. In the initial stage, the local conversion ratio increases without particle shrinkage. In the middle stage, the particle shrinks following the shrinking core model without change in the local conversion ratio. In the final stage, the local conversion ratio increases without particle shrinkage. The validity of the modified effective value was confirmed by comparison with experimental results.