Diversity of chemical composition and combustion reactivity of various biomass fuels
Journal article, 2015

A simple and fast method for measuring simultaneously the chemical compositions and combustion reactivities of biomasses and evaluating their heterogeneity was developed using a commercial thermo-gravimetric analyzer. Wood, straw, and bark pellets were selected as the biomass fuels. Compared to the variations observed for volatiles and char contents, the variations of moisture and ash contents for the three types of biomass were large in an individual pellet. The straw char was more reactive than the bark char and wood char, probably due to the high ash content of the straw, which is especially rich in potassium. Furthermore, the variations of the characteristic temperatures and kinetics in an individual pellet increased from the wood char to bark char to straw char. The experimental results for char combustion can be described by the two simple reaction models: the volumetric model and the shrinking particle model. For each type of biomass, the differences in predictions between the two reaction models were much smaller than the differences in the accuracy of the measured kinetics for the different particles. For the kinetic parameters, the activation energy E and the natural logarithm of apparent pre-exponential factor A* (lnA*) showed a linear correlation in the two applied models (A* = e((0.2140E-8.713))), while the measured activation energies of the two applied reaction models were also linear (E-shrinkingparticle = 0.8136E(volumetric)). The performed analyses revealed that 10 biomass samples could ably characterize the conversion of a batch of biomass char particles and the average kinetics of the reactions. In addition, the distribution of conversion rates of the different chars in a batch at a specific time or temperature could be estimated from the standard deviation of the average value for the kinetics.

Wood

Char combustion

Pyrolysis

Chemical composition

Devolatilization

Biomass

Residues

Chars

Pellets

Bark

Kinetic-Parameters

Pellets

Quality Properties

Kinetics

Sawdust

Author

Ke Qin

Chalmers, Energy and Environment, Energy Technology

Henrik Thunman

Chalmers, Energy and Environment, Energy Technology

Fuel

0016-2361 (ISSN)

Vol. 147 161-169 8883

Driving Forces

Sustainable development

Subject Categories

Energy Engineering

Areas of Advance

Energy

DOI

10.1016/j.fuel.2015.01.047

More information

Latest update

4/5/2022 7