Steam gasification of cottonwood (branches) in a fluidized bed

Journal Article · Tue Apr 01 04:00:00 EST 1986 · Wood Fiber; (United States)

OSTI ID:5261120

Singh, S K; Walawender, W P; Fan, L T; Geyer, W A

Cottonwood (branches) were gasified in the presence of steam in a 5.08 cm I.D. bench-scale fluidized bed reactor, over a temperature range of 850 to 1075 K. The objective of the study was to investigate the effect of reactor temperature on the produced gas composition, yield, heating value, energy recovery, and carbon conversion. The results were compared with data obtained from ..cap alpha..-cellulose in the same reactor to gain insight into the secondary gas phase reactions that occur in biomass gasification. The major components of the produced gas were CO, CO/sub 2/, H/sub 2/, and CH/sub 4/, which comprised over 90% of the gas. The gas yield, energy recovery, and carbon conversion all increased with increasing temperature: from 0.23 to 1.59 cu.m/kg dry ash-free feed, 15.0 to 96.8% and 16.9 to 87.1%, respectively. The higher heating value of the gas ranged from 12.4 to 11.6 MJ/cu.m. The dependence of the gas composition on temperature indicated the existence of two regimes for the secondary gasification reactions with a transition occurring over the temperature range of 930-950 K. The first regime (below this temperature range) was dominated mainly by the cracking of cellulose tar. The extent of lignin tar cracking was small compared to that of cellulose tar in this regime. The second regime was dominated by the water gas shift reaction. Cellulose tar cracking was essentially complete in the second regime, and the relative amount of lignin tar cracking was small. Thus the gas composition was primarily determined by the shift reaction in the second regime. The observed behavior for wood gasification was similar to that for ..cap alpha..-cellulose, although the transition from one regime to the other was not as sharp. Steam, when present in large amounts, was found to be an active gasification agent in the second regime.

• Research Organization: Kansas State Univ., Manhattan
• OSTI ID: 5261120
• Journal Information: Wood Fiber; (United States), Journal Name: Wood Fiber; (United States) Vol. 18:2; ISSN WOOFA
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090122* -- Hydrocarbon Fuels-- Preparation from Wastes or Biomass-- (1976-1989)
140504 -- Solar Energy Conversion-- Biomass Production & Conversion-- (-1989)
BENCH-SCALE EXPERIMENTS
CALORIFIC VALUE
CARBOHYDRATES
CELLULOSE
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMICAL REACTORS
COMBUSTION PROPERTIES
COTTONWOODS
CRACKING
DECOMPOSITION
ENERGY RECOVERY
FLUIDIZED BEDS
FLUIDS
FUEL GAS
FUELS
GAS FUELS
GAS YIELDS
GASES
GASIFICATION
KINETICS
LIGNIN
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PLANTS
POLYSACCHARIDES
PYROLYSIS
REACTION KINETICS
RECOVERY
SACCHARIDES
STEAM
TAR
TEMPERATURE EFFECTS
THERMOCHEMICAL PROCESSES
TREES
WOOD
YIELDS