A comprehensive study of sawdust torrefaction in a dual-compartment slot-rectangular spouted bed reactor. (15th December 2019)

• Record Type: Journal Article
• Authors: Wang, Ziliang; Lim, C. Jim; Grace, John R.
• Is Part Of: Energy. Volume 189(2019)
• Publication Date: 2019-12-15
• Subjects: Torrefaction -- Dual-compartment slot-rectangular spouted bed -- Temperature -- Sawdust -- Oxygen -- Reactor design; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2019.116306
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: A dual-compartment slot-rectangular spouted bed (DSRSB) reactor was designed and built to torrefy sawdust. The effects on torrefaction performance of temperature from 240 to 300 °C, sawdust feedrate from 600 to 1400 g/h and oxygen concentration from 0 to 9 vol% were explored. The temperature difference between the adjacent compartments was limited. Pressure drop across the reactor was affected by biomass feedrate, and was higher for the downstream compartment than for the upstream one. The weight loss of the sawdust was 9.3–38.2 wt%, while the energy yield was 65.7–99.6%. Oxidative torrefaction resulted in greater weight loss and lower energy yield than non-oxidative torrefaction. The product properties were significantly affected by the reactor temperature and oxygen concentration. Solids, liquid and gaseous products were characterized. The results showed that the DSRSB is a promising reactor for biomass torrefaction. Highlights: Spouted bed proved to be a promising torrefaction reactor. Adjacent compartments of DSRSB reactor had small differences in temperature. Sawdust lost 9.3–38.2% weight and retained 65.7–99.6% energy during torrefaction. Oxygen concentration and temperature were two important factors for torrefaction. Produced torrefied sawdust was comparable to that from other types of reactor.